Journal of— E n g l is h e d i t io n —1720

The Japan Association of Radiological Technologists

Journal of1720— E n g l is h e d it io n —The Japan Association ofRadiological Technologists

CONTENTS
2

Overview of the Japan Association of Radiological Technologists/general principles
Foreword

3

Publication of the English Version of Our Journal
Yasuo Nakazawa, President, The Japan Association of Radiological Technologists

History

4

History of The Japan Association of Radiological Technologists (JART)
Special Feature

7

The Role of Aso Medical Center During and After the Kumamoto Earthquake

16
18

A Report on the Support Provided After the Kumamoto Earthquake

Takafumi Iwamoto, Aso Medical Center Radiology Department

The 32nd Japan Conference of Radiological Technologists: President’s speech

Three Policies and Issues Facing the Japan Association of RadiologicalTechnologists
Yasuo Nakazawa, President, The Japan Association of Radiological Technologists

33

The 32nd Japan Conference of Radiological Technologists: Invited lecture

The Challenge of Teaching MRI in the Future
Dr. Grey Michael Lee, Illinois State University, Associate Professor

44

Hospital Introduction and Current Status of Regional Healthcare with
Progressing Depopulation
Kensuke Ehara, Hokkaido Association of Radiological Technologists Wakkanai Branch / Esashi Hospital52

The 32nd Japan Conference of Radiological Technologists: Keynote lecture

Introduction of Diagnostic Reference Levels to Japan
Makoto Hosono, Institute of Advanced Clinical Medicine, Kindai University

Arts and Sciences

57

material

Proposal for the Unification Labeling Stickers for Emergency Shutdown
System of MRI Equipment
Toshio Tsuchihashi, Koji Matsumoto, Yoshitada Masuda, Fumio Ishimori, Hideaki Sunamori, Isao Fujita, Toshiharu Nakai

64material

Current State of the Ionization Chamber Type Survey Meter Held by Medical
Facilities in the Kyoto Area: Questionnaire Survey and Calibration
Keiji Oosawa, Motohiro Nishitani, Toshinori Yamane, Tetsuya Ookita, Toshiaki Asano, Sousuke Kusu

71

note

Development and Evaluation of the Safety Grid Holder
Yoshinori Takao, Minoru Hosogai, Kenji Kishimoto, Shohei Sasaki, Masachika Shogaki, Takao Ichida, Momoyo Horiuchi

78

material

Fundamental Study of Magic Angle in the Meniscus of the Knee Joint
Shinjiro Kugimiya, Shinsuke Katsuki, Hisamitsu Kawasaki, Keiko Kaneko, Hideo Tsuji, Aya Kiyota, Yuusuke Miura

83

note

Volumetry of the Liver: Effect of measurement using fusion images
Chikara Noda, Toshiyuki Takahashi, Hisaya Sato, Yasuhiro Inose, Kyoichi Kato, Yasuo Nakazawa

91

the original work

The Influence of Incubators on Mobile Radiography of Low Birth Weight Infants
Shinichi Awamoto, Masahiro Ooga, Shuhei Ono, Youhei Yotsuji, Toyoyuki Kato, Yoshiyuki Umezu

Note: The contents of this magazine are those that have been published in JART magazine.

Overview of the Japan Association ofRadiological Technologists
The Japan Association of Radiological Technologists, a public interest incorporated
association under the jurisdiction of the Ministry of Health, Labour and Welfare, wasestablished in 1947 with the purpose of contributing to the health of citizens throughraising the professional ethics of members, improving and furthering the study of medical
radiology and medical radiological technology, and enhancing public health.
In light of the startling progress being made in the fields of image diagnostics andradiation therapy where radiological technologists work, it is necessary to stay constantly
aware of the latest know-how and technology. JART collaborates with other certification
agencies to enhance the capacity of all radiological technologists in general throughproviding lifelong learning seminars, short courses, academic conferences and numerous
other learning opportunities. We believe that such activities constitute our obligation as
medical professionals to the general public.
As the only medical profession that has “radiological” in its name, we strive to limit
medical exposure, to raise the standing of our profession, and to realize a professionof specialist technologists that can be advertised. And we are committed to promoting
services with you all for the provision of safe and secure medical care.

general principles
We will render our services to those in need of health care.
We will act as individual members of a health care team.
We will perform our duties in our field of specialty.
We will continue to study for the benefit of mankind.
We will respect and practice the policy of informed consent.

2 ◆ Journal of JART English edition 2017

f o r e w o r dPublication of the English Version of
Our Journal
Yasuo Nakazawa (President)

Approximately 30,000 copies of the Journal of the Japan Association of Radiologic Technologists are
published monthly, and the journal is highly acclaimed by association members. The journal has
three major roles. The first is to serve as a newsletter with information about training classes (i.e.,
continuing education) for association members that will equip them to use high-quality medical
technology in collaboration with the public and medical personnel. The second role of the journal
is to document research papers on clinical radiology that are routinely submitted by association
members and papers regarding specialized technology in various fields. The third is to document
manuscripts based on clinical technology that are contributed by members and non-members.
I will present a summary of the history of the Japan Association of Radiologic Technologists to inform clinical radiologists throughout the world of the work of clinical radiologists in Japan. The Japan Association of Radiologic Technologists was established in 1947 for the purpose of providing
national certification for clinical radiologists. Subsequently, operations were implemented for the national certification to be recognized by the government, congress, the Japan Medical Association,and the General Headquarters of the Allied Powers. Thanks to considerable effort̶truly blood,
sweat, and tears̶, the Clinical X-ray Technologists Act (Act No. 226) was promulgated in June 1951.
Following that, the Clinical X-ray Technologist Law was revised in 1968 in response to various demands. In 1983, the Radiology Technicians Act and part of the Clinical X-ray Technologists Act wererevised. The unification of professions, part of the present Radiology Technicians Act, was also accomplished. The scope of operations at this time includes routine X-ray examinations, X-ray videography, angiography, X-ray CT scans, RI examinations, and radiotherapy. In 1993, the Radiology
Technicians Act was further revised, enabling the performance of MRI examinations, ultrasound examinations, and non-mydriatic fundus photography. In 2010, assistance with the reading of diagnostic images and explanations and consultations for radiology examinations became possible. Furthermore, in April 2015, administration of contrast agents into blood vessels using an automatic contrast
injecting device, needle removal, hemostasis, examination of the lower alimentary tract (proceduresfor inserting a catheter and administering a contrast agent from the anus), and procedures for inserting a catheter and suctioning air from the anus during radiotherapy were added as duties.
The Japan Association of Radiologic Technologists will continue hereafter to expand the scope of
duties of clinical radiologists based on scientific rationale. I plan to promote excellence in the Journal of the Japan Association of Radiologic Technologists by publishing clinical, educational, and re-search results of clinical radiologists on a monthly basis. I pray that the English version of the journal will be useful to clinical radiologists all over the world.

foreword ◆ 3

History

The Japan Association ofof Radiological Technologists (JART)

1947
1951

Establishment of JART (July 13)
Promulgation of the Act on Medical Radiographers (June 11)

1979

1983

Authorization for Establishment of the Japan
Association of Radiographers (June 13)

1954

1956

1962

1968

1985
First national examination for Medical Radiographers (May 30)

Event to commemorate the 15th anniversaryof founding and 10th anniversary of enactment of the Act on Medical Radiographers,
attended by Her Imperial Highness Princess
Chichibunomiya
Promulgation of the Act to Partially Revise
the Act on Medical Radiographers (establishment of two professions) (May 23)
First national examination for radiological
technologists

1969

1975

1987

1989

1991

1993

Renaming as the JART
Staging of the 4th International Society of Radiographers & Radiological Technologist (ISRRT) World Congress at Tokyo Palace Hotel,
attended by Her Imperial Highness Princess
Chichibunomiya
Event to commemorate the 80th anniversaryof the discovery of X-rays, attended by Her
Imperial Highness Princess Chichibunomiya

4 ◆ Journal of JART English edition 2017

Partial revision of the Act on Medical Radiographers and the Act on Radiological Technologists (unification of the professions)
Event to commemorate the 90th anniversaryof the discovery of X-rays, attended by Her
Imperial Highness Princess Chichibunomiya
Staging of the 1st Japan Conference of Radiological Technologiststh

Event to commemorate the 10 anniversaryof founding, attended by Her Imperial Highness Princess Chichibunomiya

Completion of the Education Center for
JART

1994

1995

1996

General assembly resolution for establishment of the New Education Center and afour-year university
Completion of the New Education Center(Suzuka City)
Opening of Suzuka University of Medical
Science
The Act to Partially Revise the Act on Radiological Technologists, and Ministerial Ordinance to Partially Revise the Enforcement
Orders (April 28)
Appointment of the President of JART as the
11th President of ISRRT
Event to commemorate the 100th anniversaryof the discovery of X-ray, attended by Her
Imperial Highness Prince Akishinomiya
Start of the Medical Imaging and Radiologic
Systems Manager certification system• History of The Japan Association of Radiological Technologists (JART)

1998

1999

2000

2001

2003
2004

2005

2006

Staging of the 11th ISRRT World Congress at
Makuhari
Start of the Radiation Safety Manager certification system

2009

2011

2012
Start of the Radiological Technologists Liability Insurance System

Launch of the Radiological Technologists
Liability Insurance System with participationby all members

2013

2014

Establishment of the committee on Autopsy
imaging (Ai)

Appointment of the President of JART as
chairperson of the Central Social Insurance
Medical Council specialist committee

Signing of the Comprehensive Mutual Cooperation Agreement on Prevention of Radiation Exposure (September 21)
Consignment of work to measure personal
exposure of residents
Revision of the Act on Radiological Technologists, Government Ordinance to Partially
Revise the Enforcement Orders, and Revisionof the Enforcement Regulations (June 25)

Revision to the national examination for radiological technologists
Launch of the Team Medicine Promotion
Conference, with the President of JART as its
representative

Registration of transition to a public interest
incorporated association (April 1)

Renaming as public interest incorporated association JART

Relocation of offices to the World Trade
Center Building in Tokyo

Staging of a joint academic conference between Japan, South Korea, and Taiwan

Support activities following the Great East
Japan Earthquake

Event to mark the 65th anniversary of founding and transition to a public interest incorporated association (June 2)

Enactment of X-Ray Week

Start of the Medical Imaging Information Administrator certification system

Health Policy Bureau Directorʼs notification
concerning promotion of team medicine

Staging of an extraordinary general meeting
concerning transition to a public interest incorporated association” Presentation of the Medical Exposure
Guidelines (Reduction Targets)” for patients

Revision of the Medical Exposure Guidelines

2008

2010

Launch of the radiation exposure advisor
certification system

2015

Event to commemorate the 120th anniversaryof the discovery of X-rays

History of JART ◆ 5

Special Feature
The Role of Aso Medical Center During and After the Kumamoto Earthquake
Takafumi Iwamoto,
Aso Medical Center Radiology Department

A Report on the Support Provided After the Kumamoto Earthquake

The 32nd Japan Conference of Radiological Technologists

Presidentʼs speech

Three Policies and Issues Facing the Japan Association of Radiological Technologists
Yasuo Nakazawa,
President, The Japan Association of Radiological Technologists

The 32nd Japan Conference of Radiological Technologists

Invited lecture

The Challenge of Teaching MRI in the Future
Dr. Grey Michael Lee,
Illinois State University, Associate Professor

Hospital Introduction and Current Status of Regional Healthcarewith Progressing Depopulation
Kensuke Ehara,
Hokkaido Association of Radiological Technologists Wakkanai Branch / Esashi Hospital

The 32nd Japan Conference of Radiological Technologists

Keynote lecture

Introduction of Diagnostic Reference Levels to Japan
Makoto Hosono,Institute of Advanced Clinical Medicine, Kindai University

The Role of
Aso Medical Center
During and After the
Kumamoto Earthquake
Takafumi Iwamoto
Aso Medical Center Radiology Department

Introduction
Our condolences to all of those who wereaffected by the Kumamoto Earthquake. We
also extend our most sincere gratitude tothose who are involved in the rebuilding efforts and to all the volunteers.
Upon a request from the Japan Associationof Radiological Technologists, I present here
the activities of our center during the Kumamoto Earthquake, entitled: “The role of Aso
Medical Center during and after the Kumamoto Earthquake.”

Overview of Aso Medical Center
Aso Medical Center（previously Aso Chuo
Hospital）opened in the old Kurokawa Village
in 1950. However, 60 years after its opening, it

could no longer respond to new medical demands as it had become too old. To meet theneeds of cooperating with local medical institutions and enhancing the emergency medical
system, in 2006, we established the “Aso Chuo
Hospital Management Reform Committee,”consisting of experts from Aso Medical Association and associated organizations, and discussions on the direction the hospital shouldtake began.
In 2010, funding from the “Regional Medical
Revitalization Plan (Aso),” which was devised
by Kumamoto Prefecture, was applied as partof the allocated resources, and the plan tobuild the new hospital was put into place.
In January 2013, the construction began. The
main building was completed in June 2014,
and the hospital opened in August after thechangeover was complete.

Overview of the hospital facilities• Structure: reinforced concrete (4 stories)• Hospital buildings: outpatient (seismic

The newly built Aso Medical Center, which openedin August 2014.

resistant structure), central clinic (seismic isolation structure)• Number of beds: 124 (general: 120, acute: 4)• Departments: internal medicine, neurology, cardiology, pediatrics, surgery, orSpecial Feature ◆ 7thopedics, neurosurgery, rehabilitation,dermatology, and anesthesiology• Number of physicians: full-time: 10 (asof August 2016)• Advanced medical equipment: MRI, CT,angiography, etc.
• Emergency response facility: emergency
helipadOverview of the Kumamoto Earthquake
On April 14 (Thursday) at 9:26 p.m., amagnitude 6.5 earthquake (foreshock), withthe epicenter in Kumamoto District in Kumamoto Prefecture, occurred at a depth of 11
km. A seismic coefficient of 7 was observedin Mashiki, in Kumamoto Prefecture. Some
28 hours later, on April 16 (Saturday) at 1:25
a.m., a magnitude 7.3 main shock occurredin Kumamoto District at a depth of 12 km,
and a seismic coefficient of 7 was observedin Nishiharamura and Mashiki. Magnitude 7.3
is similar to the large-scale earthquake, theGreat Hansin earthquake, which occurred in
1995. Initially, the magnitude 6.5 quake on
April 14 was considered as the main shock,and any subsequent quakes were expected tobe aftershocks whose intensities were never
expected to be greater than the initial one.
However, following the above-mentioned
earthquake that occurred in the early morningof the 16th with a magnitude of 7.3, the Japan
Meteorological Agency reported on the same
day that it was the main shock and the earlier
quake (on the 14th) had been the foreshock.
During the 2011 Great East Japan Earthquake,
which was a subduction earthquake, an original report was revised, switching the order ofthe main shock and the aftershock. However,this was the first case of an intra-plate (active
fault) earthquake where a larger quake occurred following a quake with a magnitude of
6.5 or higher since the observation of earthquakes began in Japan in 1885. It was also
the first time that two seismic coefficients of 7

8 ◆ Journal of JART English edition 2017

were observed in one series of seismic activities. The earthquake on the 14th was due toactivities on the northern edge of the Hinagu
fault zone, while the earthquake on the 16th
was due to activities on the Futagawa fault
zone. These are considered to be consolidated earthquakes as the two neighboring fault
zones are linked. Furthermore, after the main
shock on the 16th, earthquakes continued tooccur in the area between Aso, Kumamoto(northeast of Kumamoto District), the western Oita Prefecture, and the central Oita Prefecture (around the Beppu-Haneyama Fault
Zone): Active seismic activities were observedin the three areas, including Kumamoto District.
(from the Wikipedia article on the 2016 Kumamoto Earthquake)

Damage in the Aso area①
From the Aso City official Facebook page

Damage in the Aso area②
From the Aso City official Facebook page

The Role of Aso Medical Center During and After the Kumamoto Earthquake

Damage in the Aso area③
From the Aso City official Facebook page

hospital for Aso area medical care, our hospitalbuilding is a seismic isolation facility (partially seismic resistant) that is resistant to disasters. Since weare equipped with a generator and a water tank,during this major disaster, we were able to provide medical care while maintaining all medical
functions. However, immediately after the disaster,
surrounding roads were destroyed and many staff
were unable to get to the center; thus, a limited
number of doctors (4 out of 9 full-time doctors
were able to arrive) and medical staff diagnosed
and treated emergency patients. In addition, as
many residents were evacuated to our center, itfilled with emergency patients and evacuees. Furthermore, many medical facilities had difficulties
maintaining their functions immediately after thedisaster, and patients gathered at our center. The

Damage in the Aso area④
From the Aso City official Facebook page

Maintaining function as a disasterbase hospital after the Kumamoto
Earthquake
The Aso area during the April 14 earthquake(foreshock of the Kumamoto Earthquake) experienced a seismic coefficient of 5 but did not suffer
severe damage. Subsequently, upon a request from
Kumamoto Prefecture, the DMAT (Disaster Medical
Assistance Team, including myself) was dispatchedfrom this center and conducted fieldwork at Mashiki town office on the instructions of the Japanese
Red Cross Kumamoto Hospital DMAT field headquarters.
During the April 16 earthquake (the Kumamoto
Earthquake main shock), the Aso area experienced
a seismic coefficient of 6 plus, and suffered severe
damage, such as landslides, collapsed homes, anddisruption to daily life, due to the closure of prefectural and national roads. As the disaster base

The DMAT team, members of which arrived fromacross Japan.

A meeting at the DMAT field headquarters.
Special Feature ◆ 9next day, we received support from many DMAT
and rescue teams from across Japan, and we wereable to maintain our role as the disaster base hospital.

DMAT field headquarters provisionof medical support for the Aso area
We set up our base for the field hospital on April
17 to provide medical support to the Aso area andalso to gain an understanding of the situation. Up
to 33 DMAT members were in the base at times,
providing medical support to evacuation sheltersand hospitals in the surrounding Aso area, with ourcenter used as the base. From April 22, the function of DMAT was transferred to public health centers and relief teams, and Kumamoto Prefecture set
up an Aso Disaster Recovery Organization (ADRO).
Our center continued to be the headquarters for

operations.

Free drinks during the disaster
Following the Kumamoto Earthquake, the Asoarea suffered severe damage to its water and sewer
services, and many areas were without these services for a long time; therefore, we provided freedrinks for 30 days based on a cooperation agreement with a vending machine company, APEX
Corporation, West Japan. The company had offeredto provide free drinks for up to 30 days or up to
10,000 cups during a disaster. It was not limited todrinks such as juices, but also included water andhot water, which were used by many people toprepare milk for infants, and this was highly appreciated.

A vending machine with cups, from which freedrinks were provided during the disaster.

ADRO conference.

ADRO headquarters.

10 ◆ Journal of JART English edition 2017

Medical device usage after the disaster（ radiology-related equipment ）Following the earthquake on April 16, medical devices at our center were operated withemergency power from a generator. However, the radiology-related equipment could
not be operated with emergency power, and,thus, diagnoses were based on general imaging with a portable imaging device (flatpanel) and laptop computer-style console atthe beginning (for about two days). On April
17, power companies around Japan provided
repairmen, power supply vehicles, and aerial

The Role of Aso Medical Center During and After the Kumamoto Earthquake

The angiography room immediately after theearthquake.

The seismic isolation structure of our center.

The axis of the arm shifted.

The radiology staff room immediately after theearthquake.
A bookshelf collapsed and the books were scattered around.

Horizontal marking panel after the earthquake.

Testing with a portable unit immediately after theearthquake (general imaging room).

The main building shifted by between 40 cm and 50 cm
in all directions.

Tracing on the horizontal marking panel.

Special Feature ◆ 11

work vehicles, restoring power to our center.
On April 18, the service personnel for thehospital equipment began to visit from earlymorning, and repaired and inspected eachdevice. By the afternoon, all the devices wereoperational. Thanks to the seismic isolation
facility at our center, damage to the medical
devices was minimal, and tests could be restarted promptly. It made us truly appreciate
the power of the seismic isolation facility.
The server room of our center.

Devices used by the Radiology
Department① 1 CT (80 slices)② 1 MRI（1.5T）③ 1 angiography device (biplane)④ 1 general imaging device (two sourcesand one room)④ 3 FPDs (flat panels)⑤ 2 portable imaging devices⑥ 1 X-ray TV⑦ 1 mammogram⑧ 1 bone density measurement device⑨ 2 surgical imaging devices

The medical information system
functioned as normal on emergency
power
The server rack in the server room (the OA
floor) was fixed in place with anchors, and,thus, the rack was undamaged. Furthermore,
the server room was designed to operate withemergency power in mind (including air conditioning); thus, medical care was smoothly
administered following the earthquake using electronic files, PACS, and other systems.
Our center is equipped with free Wi-Fi, andthe Internet could be accessed even after theearthquake. Thus, the DMAT field headquarters was useful for a wide range of people in
conducting various tasks, such as inputting for

12 ◆ Journal of JART English edition 2017

Fixed server rack.
It withstood a seismic coefficient of 6 plus.

the Emergency Medical Information System(EMIS).

Appreciation of compassionate
medical support
With the increase in the number of patientsat the emergency department following the disaster, the number of tests, such as general imaging and CT scans, increased not only during
the day but even at night. Therefore, the testing department had to operate on both 24hour shifts and on overtime during the night,
at weekends, and during holidays. This centerhas five medical radiological technologists(two males and three females) on call for thenight time, weekends, and holidays in normal

The Role of Aso Medical Center During and After the Kumamoto Earthquake

times. In addition, since I was working as amember of DMAT at the disaster headquarters, I was able to respond with a team of four
technologists immediately after the disaster. As
the time went on, the technologists grew increasingly fatigued, and upon consulting withthe hospital director and chief technologist, it
was decided that medical radiological technologists (including the nurses, pharmacists, andclinical technologists) should be dispatched to
the DMAT field headquarters. Mr. Kinya Ono
─ a member of Kanagawa Prefecture DMAT
and a former director of the Japan Association of Radiological Technologists ─ was at the
DMAT field headquarters. Subsequently, with
Mr. Ono acting as the liaison, the Japan Association of Radiological Technologists contact
system allowed for rapid dispatch and support
for all those involved.
The Japan Association of RadiologicalTechnologists, the Kumamoto Association ofRadiological Technologists, the Oita Association of Radiological Technologists, the Saga
Association of Radiological Technologists, theFukuoka Association of Radiological Technologist, Kumamoto City Hospital, DMAT, andthe relief team sent us between one and three
medical radiological technologists in turnfrom April 20 to May 8 (a total of 20 technologists). On April 22, Mr. Kiyoshi Ogawa, theVice-president of the Japan Association ofRadiological Technologists (at present, a supervising specialist) and Mr. Yuji Yasukawa,a specialist, visited our center, confirmed thedisaster situation, and gave encouragement
to the Radiology Department staff. We truly
appreciate everybody who agreed to cometo provide support when much of the normal
communication infrastructure, such as the national and prefectural roads, were closed or
destroyed due to the disaster.

From left to right: Kinya Ono, ex-Director; Kai,
the Hospital Director, Hiroshi Kuwahara, the Oita
Association of Radiological Technologists Vicepresident.
Vice-president Kuwahara rushed to our center to provide
assistance.

Directors of radiologist associations in Kyushu
visited our center.

Vice-president Kiyoshi Ogawa, pictured center（thecurrent supervising specialist）, and specialist Yuji
Yasukawa on the right.

Special Feature ◆ 13

Issues that arose throughexperiencing the earthquake
After the earthquake, an information session on the disaster was held at the center(for each department), and the most common
comment made was the necessity for disasterprevention and a response manual for thecenter. This should be prepared immediately,
and upon completion, all staff should be fully
informed. There also was a request for regulardisaster training.
The challenge for the Radiology Department
was the need for devices that can function on
emergency power. Observing the emergency
outpatients immediately after the earthquake,it could be seen that the majority of the cases
were head trauma ones (due to falling furniture, etc.), and there were many requests for
CT scans by diagnosing doctors. Two days
after the main shock, the CT was functioning
again, and there were nearly double the usu-

After thedisaster

Emergency department:
number of patients

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Number of CT scans
After thedisaster

Emergency department: number of patients
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14 ◆ Journal of JART English edition 2017

The Role of Aso Medical Center During and After the Kumamoto Earthquake

al request for CT scans. Thus, a functioning
CT during a disaster will lead to accurate diagnosis and treatment by doctors. However,since there are issues such as power capacity
at this center, it must be a careful process
conducted in cooperation with the hospital.
We were able to overcome the acute and subacute phases of the disaster with the supportof many medical radiological technologists.
But there is also a future challenge to be met
in that it took time to get familiar with thedifferences in the different makes of devices
we use at our center, the operation method
for the electronic files, and the operation ofdevices. Thus, the Radiology Department prepared a simple operation manual for each device.

Conclusion
I worked in the field as a member of DMAT
from the early stage of this disaster, and following the main shock, I took part in establishing and managing the disaster response
department at our center. Looking back, I
regret my inexperience, but at the same time,

I feel that I did the best I could with the support and cooperation of many people. I amvery grateful to them. At the same time, I am
happy that I met many people and was inspired by them. The Kumamoto Earthquake
was unexpected, reminding me that a disastercan take place anywhere, anytime. We medical radiological technologists may be facing
a time when we need to review what we cando in a disaster and to improve our skills. Allof us medical radiological technologists needto think together.

Acknowledgements
We want to take this opportunity to thankthe Japan Association of Radiological Technologists, the Kumamoto Association of Radiological Technologists, the Oita Association of Radiological Technologists, the Saga Associationof Radiological Technologists, the Fukuoka
Association of Radiological Technologists, Kumamoto City Hospital, the members of DMAT,
and the relief team, who have all cooperated
with and supported this center since the disaster.

DMAT members and the relief team members who worked at our center wrote
messages on these boards.
Special Feature ◆ 15

A Report on the Support Provided
After the Kumamoto Earthquake
On Monday August 1, 2016, the President,
Mr. Nakazawa; Mr. Eto, the Kyushu Regional
Director; Mr. Nakamura, Fukuoka Prefecture
President; and Mr. Kato, the manager, visited
Aso Medical Center, the Department of Medical Care, Medicine, and Drugs, Health, andWelfare, Kumamoto Prefectural Government,
and the Kumamoto Association of Radiological Technologists. They reported on the sup-At the Kumamoto Prefectural Office
Left to right: Mr. Nakamura, Fukuoka Prefecture President; Mr. Hiai,
KART President; Mr. Anan, Assistant Director of the Department ofMedical Care, Medicine, and Drugs, Health, and Welfare, Kumamoto
Prefectural Government; Mr. Nakazawa, the President; Mr. Nakagawa,Councilor at the Department of Medical Care, Medicine, and Drugs,
Health, and Welfare, Kumamoto Prefectural Government; and Mr. Eto,
Kyushu Regional Director.

port efforts that our association has been providing since the Kumamoto Earthquake. They
passed on donations from the technologist
associations of various prefectures and frommembers.
At Aso Medical Center, to which we dispatched medical radiological technologists,
Hospital Director Yutaka Kai, Chief Technologist Nobuaki Anai, and all the staff acknowl-

With the KART President, Yasuhiro Hiai.

Seismic isolation structure at Aso Medical
Center.

With the Hospital Director, Yutaka Kai.

Presentation on the disaster response by the
Hospital Director, Yutaka Kai.

16 ◆ Journal of JART English edition 2017

Presenting a report of our support efforts at the Departmentof Medical Care, Medicine, and Drugs, Health, and Welfare,
Kumamoto Prefectural Government.

edged the support received for the Kumamoto
Earthquake disaster, and Hospital Director Kai
reported on the past efforts of the hospital
since its establishment, as well as the situation, response, and support system during theearthquake. In addition, we toured the seismic
isolation structure that was completed in June
2014, and received an explanation on the usefulness of a seismic isolation structure during
an earthquake.
At the Department of Medical Care, Medicine, and Drugs, Health, and Welfare, Kumamoto Prefectural Government, Councilor
Hiroki Nakagawa and Assistant Manager
Shunzo Anan, who has been the liaison with
our association since the earthquake, relayed
the acknowledgment of our support. We explained and reported on our efforts since theearthquake, and promised that we would actively provide support if there were any futuredisasters.
At the office of the Kumamoto Associationof Radiological Technologists, the President,
Yasuhiro Hiai, the Vice-President, Akihito
Nishiono, and directors Yoshiko Nakajima,
Koji Shimokawa, Toshikazu Fukushima, Yuji
Yano, and Shinnosuke Tagami welcomed us
and expressed their gratitude to our association and the prefectural associations of radiological technologists while passing on storiesof their struggle since the earthquake until
today. We reviewed our support efforts andpresented a donation of 847,986 yen collectedfrom the prefectural associations of radiological technologists and members.

At the office of the Department of Medical Care, Medicine, and Drugs, Health, and Welfare, Kumamoto Prefectural
Government
From left to right: the Kumamoto Prefectural Directors, Mr. Tagami, Mr. Yano, and Mr. Fukushima; the Vice-President, Mr. Nishiono;
the President, Mr. Hiai; the President, Nakazawa; the Kyushu Prefectural Director, Mr. Eto; the Fukuoka Prefectural President, Mr.
Nakamura; and the Kumamoto Prefectural Directors, Mr. Shimokawa and Ms. Nakajima.

Special Feature ◆ 17

The 32nd Japan Conference of Radiological Technologists

Presidentʼs speech

Three Policies and Issues Facing theJapan Association of RadiologicalTechnologists
Yasuo Nakazawa
President, The Japan Association of Radiological Technologists

Conference Chairman Eisuke Yasuda: We will

now hear from President Yasuo Nakazawa,
who has served as the leader of the Japan Association of Radiological Technologists sinceJune 2010. Today, he will share his thoughtson three policies and issues that will affectour future.
Ladies and gentlemen, President Yasuo Nakazawa.
President Yasuo Nakazawa: Thank you forthe introduction. My name is Yasuo Nakazawa of the Japan Association of RadiologicalTechnologists. The theme of my speech today
is “three policies and issues facing the Japan
Association of Radiological Technologists.” My
address is divided into five sections. First, I
will report on JARTʼs initiatives after the Kumamoto earthquake. Second, I will introduce
the policies that concern JART. Thirdly, I will
discuss the thorough reforms of the Radiological Technologist Law, which is one of todayʼs
three policies. Fourth, I will discuss the regulations for the education of radiological technologists and the shape that clinical training
should take. This is the second policy, andis an area we are struggling with right now.
Fifth, I will explore the shape the educational
system should take with an eye to the future,
which is todayʼs third policy.

18 ◆ Journal of JART English edition 2017

1. Report on the associationʼs initiatives
after the Kumamoto earthquake
Before discussing our associationʼs activities
in response to the Kumamoto earthquake, I
would like to express my deep sorrow overthe earthquake victims, and my sincere sympathy for everyone who was affected by thedisaster. The Kumamoto earthquake struckat 9:26 p.m. on April 14. Around 9:30 p.m., I
received a call from JART director Naoki Kodama, who informed me of the crisis in Kumamoto Prefecture. I quickly asked our vicepresidents to gather more information. The
next day, April 15, the first disaster responsemeeting was held. The president of the Kumamoto association, Yasuhiro Hiai, happened
to be in Yokohama for the Japan Radiological
Congress, so we were able to contact him
quickly and ask him for information and reports. He also took part in the meeting.
At the meeting, decisions were made on
various matters including our response to thedisaster, information gathering, dispatching afact-finding team, and collecting donations fordisaster victims. Six more disaster response
meetings were held. On April 18, I attended
the 22nd meeting of the Disaster Victims HealthSupport Council to report on our associationʼsdisaster response. This council is composedof 19 organizations and 38 groups involved in
medicine and nursing. It is chaired by Yoshitake Yokokura, head of the Japan Medical Organization. Its meetings are attended by section
chief-level officials from multiple government
ministries and agencies including the Ministryof Health, Labour and Welfare (MHLW) ; theMinistry of Education, Culture, Sports, Scienceand Technology (MEXT); the Ministry of Internal Affairs and Communications; the Cabinet Office; and the Environment Ministry. The
councilʼs first meeting was in April after thedisaster struck on March 11, 2011, and havecontinued convening ever since. Its role is toserve as a liaison for Japanese medical professionals involved in health support. At themeeting, we asked the government to thoroughly investigate whether the earthquake
had caused any radiation leaks at the Sendia
nuclear power plant in Kagoshima Prefecture,
the Genkai nuclear plant in Saga Prefecture,or the Ikata nuclear plant in Ehime Prefecture.
If such a possibility existed, we stated that
JART was ready to send surveyors. On April
22, a survey team was dispatched to the disaster response headquarters in Kumamoto Prefecture under the leadership of specialist andformer JART vice president Kiyoshi Ogawa,director Shogo Azemoto, and specialist Yuji
Yasukawa. We told the team that JART was
prepared to provide assistance for any damages caused by the disaster. The team visitedthe Japanese Red Cross Kumamoto Hospitaland the Aso Medical Center to inquire about
the situation on the day of the disaster andwhat had happened since, as well as to discuss arrangements for communications andsupport at the Aso Medical Center. The Aso
Medical Center is a seismically isolated structure, so it sustained very little damage. It wasarranged so that medical activities in the Aso
region were focused around the Aso Medical
Center. As the large number of patients left
the local radiological technologists exhausted, the association received a request to sendmore staff. JART regional director Akinori
Hiroki, Oita association president Yoshihiro
Eto, Fukuoka association president YasuhikoNakamura, and Kumamoto association president Yasuhiro Hiai discussed the matter anddecided that support should come from thetechnologist associations closest to the disaster
Special Feature ◆ 19

Kumamoto prefecture disaster

Diagram of the system for dispatching
診療放射線技師派遣体制図radiological
technologists

headquarters
熊本県災害対策本部

The disaster medical assistance team
阿蘇医療センターに参集したＤＭＡＴ(DMAT) meets at the Aso Medical Center

4

Fig.1

area. This picture shows Kumamoto disaster
response headquarters assistant section chief
Shuzo Anan speaking with former JART vicepresident Kiyoshi Ogawa (Fig.1). This picture
shows some of the damage in Kumamoto thatpresident Yasuhiro Hiai described to us. You
can see that an X-ray tube has fallen down
onto the bed, a control box has fallen over,
and an X-ray monitor is off kilter. After hearing a report on the situation and discussing itat the Aso Medical Center, work began on atechnologist dispatch system. In this system,
when a request for a radiological technologist
came in from a medical institution, the Aso
Disaster Recovery Organization (ADRO), thenorthern Kumamoto Prefecture branch, and
JART would decide on which staff to dispatch.
Radiological technologists from the JART
team entered the area on April 22, and waspreceded by Oita association vice president
Hiroshi Kuwahara. Also on April 22, requests
for support were sent out to Oita, Fukuoka, Saga, Kumamoto, and other prefectures,
which responded by sending staff. I would

20 ◆ Journal of JART English edition 2017like to express my sincere gratitude to the radiological technologists who provided support
and to the chief radiological technologists andhospital directors at the medical institutions
involved.
JART collected donations until July 31. On
August 1, I visited the Kumamoto prefectural
office to meet with assistant secretary Hironori
Nakagawa and assistant section chief Shuzo
Anan to report on our activities. The meeting
was also attended by president Yoshihiro Eto,
president Yasuhiro Hiai, and president Yasuhiko Nakamura (Fig.2).
In the morning before the meeting at theprefectural office, we visited the Aso Medical
Center to give director Yutaka Kai a report on
JARTʼs activities. Hospital Director Yutaka Kaigave us a 45-minute explanation of the Centerʼs initiatives. We then visited the Japanese
Red Cross Kumamoto Hospital where theKumamoto radiological technologist association office is located, and presented president
Yasuhiro Hiai with approximately ¥840,000 in
donations collected from around the country.

Three Policies and Issues Facing the Japan Association of Radiological Technologists

Visiting the
Aso Medical Center
Director Yutaka Kai
阿蘇医療センター
甲斐院長を訪問

Visiting
assistantsecretary Hironori Nakagawa and assistant
熊本県庁
中川審議官・阿南課長補佐を訪問
section chief Shuzo Anan at the Kumamoto prefectural office
Visiting the office of the Kumamoto Association of
熊本県放射線技師会事務所を訪問Radiological Technologists

Presenting
donations to support recovery from the
熊本地震震災支援金交付式
Kumamoto earthquake

6

Fig.2

This picture shows the Kumamoto association
board members (Fig.2). We are grateful to everyone who donated from around the country.

2. Introduction to policies thatconcern JART
Next, I would like to discuss policies thatconcern JART. Since I became president of theassociation in June 2010, the executive team,
who worked together with the membership,
has studied and drawn up various policies,
particularly ones related to the government.
The first involves upgrading education for radiological technologists and improving theirenvironment based on the Basic Plan to Promote Cancer Control Programs. In 2011, a survey was conducted on cancer hub hospitals
nationwide. Based on this, I have requested
that three radiological technologists be assigned to each linear particle accelerator. The
second involves the activities of radiological
technologists in promoting team medical care.

In April 2011, we formed a committee to promote team medical care in cooperation with
the Ministry of Health, Labour and Welfare .
Prior to this, a national survey on JARTʼs situation was conducted from January to March
2011. Based on the surveyʼs results, the committee discussed how to promote team medical care so that ʻgray zoneʼ duties performedby radiological technologists would be clearly
within the scope of the law. After three years,
we were finally able to amend the law, andare currently holding standardization lectures
based on these amendments.
However, not all of our proposed job expansions were realized, so we would like toreopen discussions on promoting team medical care with the MHLW on the remaining
issues.
The third involves creating a suitable work
management system to ensure medical safety.
Using a system to manage medical radiation
exposure, we have been certifying institutions
that successfully reduce radiation exposure.
About 30 facilities nationwide have been certiSpecial Feature ◆ 21

fied since I became president. There are now
66 such institutions, which is an increase of
36 over the last six years. Today, I would liketo urge those from other institutions to seek
certification for reducing radiation exposure.
I once asked Takeshi Sasaki, the former headof planning at the ministryʼs medical department, if certification for reducing medical
radiation exposure could be reflected in compensation for medical services. His response
was that the number of institutions was still
too small. He told me that if there were three
to five certified institutions in each prefecture,
increasing the number of institutions certified
for reducing medical radiation exposure could
become a matter of policy. We formed a commission to look into the issue, and found that
one issue is the fees needed to obtain certification. I therefore urge your institutions tobudget for certification and to prepare a year
and a half or two years in advance.
A management system for medical equipment was created when the revised Medical
Services Law was enforced on April 1, 2007,
which represented a major change to Japanese medical policy. This was centered onfour pillars: medical safety, infection control,
management of medical products, and man-

22 ◆ Journal of JART English edition 2017

agement of medical equipment. Regulations
for these areas were clearly laid out in the
Medical Services Law. We have undertaken
the task of drawing up policies for systems to
manage medical equipment in radiology departments. Currently, Yasuhiko Nakamura isheading the radiology equipment supervisor
section, which conducts an annual nationwide
survey on medical and radiology equipment
malfunctions. The yearly totals are then reported to the MHLWʼs economy section. We
have asked that the CT, MRI, isotope, and other equipment we use be included when thescope of the “medical equipment safety management fees – 1” is expanded. People at institutions that would like to participate in these
initiatives can contact Yasuhiko Nakamura at
the radiology equipment supervisor section.
Next is a management system for image
quality control. We have obtained data on thisfrom the medical compensation policy planning committee, and are currently discussing
the matter with the MHLW.
Fourth is the composition of the national
examination committee. When I became president, it had been 60 years since the national
examination system began. Over those 60
years, all the chairs and vice chairs of the na-

Three Policies and Issues Facing the Japan Association of Radiological Technologists

tional exam committee had been physiciansfrom the Japan Radiological Society. Our opinion is that the education of radiological technologists should be carried out by radiological
technologists. We believe that radiological
technologists should play a leading role in thenational exam to the MHLW, and asked themto allow radiological technologists to be chairs
or vice chairs of the national exam committee.
However, the response we received in 2011was harsh. The person in charge of the matter
asked us, “Do you have that kind of ability?”and rejected our written request. A year later, in 2012, we tried to renegotiate with the
MHLW. We asked what was needed for themto consider our request, and were told that
we needed to provide evidence. We surveyed
the number of radiological technologists who
were professors, associate professors, lecturers, and assistant professors in universities
nationwide, as well as how many of these
individuals had doctorates; we then included
these findings in a written request to the Ministry in 2013. However, the number of doctorates was a bit too low. Compared to 98%
of doctors and 89% of scientists and technologists, only 69% of radiological technologists
were doctorates. In the end, we reached acompromise to add one vice chair to the national exam committee. I urge professors andassociate professors at educational institutions

who do not have doctorates to pursue higher
degrees. Having a large number of radiological technologists with doctorates is an extremely valuable tool we can use when dealing with the MHLW. I ask everyone working
at educational institutions to cooperate with
us in this.
Fifth is transitioning to four-year universities
and systematizing postgraduate clinical training,which falls under the second of todayʼs threepolicies. At our general meeting, we decided
to move toward four-year universities, and are
currently working to make this happen. Three
years ago, I visited technical schools aroundthe country to ask three-year schools to become universities, or if that was not possible,
to switch to four-year programs.
Sixth is the posting of civil servants who
specialize in addressing acute radiation exposure and medical radiation exposure. After the
March 11 disaster, we asked that civil servantsin charge of radiation management stationed
within 30 kilometers of nuclear power plants
to be certified radiological technologists.
Seventh is the activities of radiological technologists in education and public relations
about radiation. The pioneering work being
done in Oita Prefecture should serve as amodel for this.
Eighth is amending the Radiological Technologist Law, which is one of todayʼs threepolicies and something we have also requested from the MHLW. Ninth is the proper roleof medical physicists, and tenth is work-lifebalance. We need the relevant stakeholders toaddress these areas in evidence-based ways.

3. Policy 1 – Thorough reform of theRadiological Technologist Law
The first of the three major policies is carrying out a thorough reform of the RadiologicalTechnologist Law. Our profession was given
legal standing in 1951 by the Medical X-Ray
Technician Law. It has been 60 years sinceSpecial Feature ◆ 23

our qualifications were established, and now
a number of major reforms are necessary. In
2012, a committee was formed to study how
the Radiological Technologist Law should be
amended. The committee held discussions for
one year, then submitted a report on September 21, 2013. This report was made available
for public comments, and is now being used
as a basis to create the necessary documents.
This fiscal year, the matter is being considered
once again. In particular, the report addressed
article 2 of the Radiological Technologist Law,
which concerns definitions.
The report stated that three articles neededthorough reform: article 20 on the qualifications for the national exam, article 24 on examinations, and article 26 on instructions fromdoctors and dentists.
The following points are important. First,
amending the Radiological Technologist Law
is necessary when the Medical Services Law
is amended. Second, the Radiological Technologist Law needs to be amended to reflect
the expanded scope of our duties. Third, theeducational curriculum needs strengthening tofurther develop our radiology duties, and theRadiological Technologist Law needs to reflect this. Fourth, prescription verifications areneeded to ensure medical safety, and the lawneeds to be amended to reflect this. And lastly, the Radiological Technologist Law needs tobe amended to reflect compliance and othermatters.

all medical equipment needs to have maintenance and inspection plans by 2015. Data
from JIRA surveys shows this was achieved in
77.4% of cases in 2009 and in 90.1% of casesin 2015, indicating that while it has not beenachieved for all medical equipment, the situation is gradually improving. It also became
compulsory to appoint safety officers for medical equipment. By number of beds, this was
93.1% accomplished around 2012 and 90.1%
currently, indicating that the level is hovering
around 90%. I would urge everyone to makesure safety officers are appointed. The proportion of medical equipment safety officers
who are radiological technologists went from
27.6% to 27.7%, then 22.7% in 2015; those
who were clinical engineers went from 31.1%
to 31.2%, and those who were doctors wentfrom 30.9% to 34.3%. While the proportion ofclinical engineers is around 30%, only around
20% are radiological technologists. Nationwide, only about 20% of the medical equipment safety officers appointed based on therevised Medical Services Law are radiological
technologists. However, we believe that weshould be responsible for the radiation weuse. Therefore, we want to change article 2 of
the Radiological Technologist Law by adding
to the existing definition (“A person who exposes human bodies to radiation.”) with thefollowing: “A person who maintains and manages equipment and performs quality control
during medical care.”1）Amending the Radiological Technologist

2）Amending the Radiological Technologist Law

Law to align with the Medical Services Law

to reflect the expanded scope of our duties

The first matter is amending the Radiological Technologist Law to align with theMedical Services Law. In the revised Medical
Services Law implemented in 2007, formulating maintenance and inspection plans for
medical equipment was one of the specificpolicies on safety management for medical
equipment, which is one of the four pillars
I mentioned previously. The law states that

The next matter concerns amending theRadiological Technologist Law to reflect the
expanded scope of our duties. The committee
for promoting team medical care worked forthree years, and we are now holding standardization lectures. Everyone is well awareof the content of these lectures: intravascularadministration of contrast agents and additional duties concerning the lower digestive tract

24 ◆ Journal of JART English edition 2017

Three Policies and Issues Facing the Japan Association of Radiological Technologists

3）Strengthening the educational curriculum todevelop our radiology duties, and amending theRadiological Technologist Law to reflect thisand image-guided radiotherapy.
In addition, we have submitted a written
request concerning our duties during healthscreenings. This request concerns the attendance of doctors or dentists during screenings
for gastric cancer, breast cancer, and lungcancer. Unfortunately, screenings for gastriccancer and breast cancer were excluded fromthe latest evaluations, so our request was notrealized. We thus believe it is necessary to
drastically change article 26 of the Radiological Technologist Law so the law reflects the
expanded scope of our duties.
Furthermore, this law has not been changed
since 1951. Since it states that doctors anddentists are to provide “specific” instructions,doctors need to be present at screenings for
gastric cancer and breast cancer. Even though
it is the radiological technologist who is doing the actual work, if a doctor is not present,
the screening cannot be performed. Resolving
this would require amending article 26 of theRadiological Technologist Law. Removing the“ specific” and amending the law so it only
requires comprehensive instructions would
allow us to comprehensively carry out screenings for gastric cancer and breast cancer.
We believe this change is necessary for thewell-being of the public.

This matter involves strengthening the educational curriculum to further develop our radiology duties, as well as amending the Radiological Technologist Law to reflect this. When
the Radiological Technologist Law was written
in 1951, it laid out a two-year educational system. In 1968, a three-year education system
was launched. Looking at our duties around1970, they mainly involved simple X-ray imaging, as well as X-ray TV of the digestive tract
and other areas, angiography, radioisotope
exams, cobalt therapy, and superficial treatments. A three-year educational system was inplace at this time. However, as you all know,
our duties have substantially increased sincethen. The arrival of X-ray CT was followed
by SPECT/CT and PET/CT, and then therapies that use radioisotopes internally wereintroduced. Our duties have also expanded
to include removing needles, stopping bleeding, explaining the exams, assisting in image
interpretation, ultrasonography, non-mydriatic
fundus cameras, nuclear medicine diagnostic equipment, and inserting tubes for IGRT.
In the years since the three-year educational
system began in 1968, our duties have continued to expand, their quality and quantity has
increased, the times have gone from analog todigital, and things are continuing to progress.
In fact, while the law is still based around thethree-year system, our survey showed that
70% of institutions are already providing university education. One junior college is going
to become a university next April, which will
increase this figure to 72%. When we consider
the facts along with the increase and changes
to our clinical duties, it is clear that we should
transition to a four-year university system.
At present, the foundation of the three-year
system is still in article 20, which lays out thequalifications for taking the radiological technologist exam. We would like to amend article
Special Feature ◆ 25

20 by exchanging item 1 for item 2, and item
2 for item 3.
4）Prescription verifications to ensure medical
safety and amending the law to reflect thisThe next matter concerns prescribing verifications for ensuring medical safety andamending the law to reflect this. When radiological technologists receive an order from a
doctor in a clinical department, they always
confirm the order before carrying out the
test. For example, confirming whether it is
the right or left knee, or if it is an upper abdominal or lower abdominal CT. In order toverify the actual situation, from December 1,
2012 until February 14, 2013, surveys wereconducted on 1,129 hospitals and clinics randomly selected, and responses were obtained
from 647 facilities. What was found was thatradiological technologists at many medical institutions were actually carrying out certifications in the form of verifications.
However, we also learned that these were
not being reported. I urge all of your institutions to file incident reports when a prescription verification finds that right should havebeen left, left should have been right, or up-

26 ◆ Journal of JART English edition 2017

per should have been lower.
The survey also received 246 responses saying that “order slips are issued disproportionately by a specific person” and 222 responses
saying they are issued “disproportionately by aspecific department.” We conducted a survey
last year at Showa University Dental Hospitalwhere I work. Verifications are required at
pharmacies based on article 24 of the Pharmacist Law, so surveys of verifications are always
discussed at meetings. We similarly performeda survey of the radiation office. There were
181 verifications over one year, about 35.9%
involving the pharmacy. From a medical safety standpoint, I encourage all clinical departments to do the same. I do not think verifications are just a problem for radiological technologists or pharmacists. Instead, they need tobe carried out for examination and treatment
requests by all medical professionals. At present, prescription verifications are not part ofthe law, so I would like to add an article 25
to stipulate that if a radiological technologist
is unsure about an examination or treatment
request, irradiation cannot be performed until
the uncertainty has been resolved with thedoctor or dentist who issued the request.

Three Policies and Issues Facing the Japan Association of Radiological Technologists5）Amend the Radiological Technologist Law
to reflect compliance and other matters

To understand how to amend the Radiological Technologist Law to reflect compliance,
we studied how this is handled by other professions. We found that public health nurses,
maternity nurses, nurses, and assistant nurses
must submit a report every two years to thegovernor of the prefecture where they work.
This provision comes with a penalty. Doctors,
dentists, pharmacists, dental hygienists, anddental lab technicians must submit a report
every two years to Minister of Health, Labourand Welfare via the governor of the prefecture where they work. Dentists and dental lab
technicians must also submit a report to thegovernor. Similarly, I believe our profession
needs to submit reports based on compliance.
This year we launched a committee to study
this information, which is also being examined by a panel that is looking at the problems with the Radiological Technologist Law.
Conditions governing the relationships between doctors and other medical professions
are laid out in article 17 of the Medical Practitioners Law. Medical care cannot be carriedout by anyone except a doctor. Therefore, thecurrent Radiological Technologist Law lays out
subordinate legal relationships with respect
to doctors and the Medical Practitioners Law.
This is also seen in the laws governing otherspecialized medical professions, which highlights the need for drastic reforms.

4. Policy 2 – Regulations for the educationof radiological technologists and theshape that clinical training should take
The second policy concerns regulations
governing the education of radiological technologists and the shape that clinical training
should take. In 2014, we asked MEXT and
MHLW to reexamine our regulations andclinical training. As a result, JART and six
teachers from the national association for ra-

diological technologist training studied how
the Radiological Technologist Law should address clinical training regulations. Considering
the achievements of team medical care andthe aforementioned expansion in our duties,
MHLW officials took part in reexamining theregulations to reflect our expanded duties in2014 and 2015.
Along with pathophysiology, clinical anatomy, and clinical pharmacology, the committee
to promote team medical care instructed us
to include medical safety management, so wecame up with 99 credits. However, due to opposition from the Japan Radiological Society,only the current 95 credits were accepted inmeetings with the MHLW.
The regulations governing our profession
are now 15 years old, and are in need ofsubstantial reform. We asked the MHLW for
assistance, which officials there agreed toprovide. However, they asked that JART andpeople from radiological technologist training
institutes around the country examine the regulations together, so a committee comprising
six people form the national association andfive people from JART spent a year examining
the issue. During the discussions, we came up
with a total of 105 credits: 14 credits on basic
disciplines; 13 credits on the structure andfunctions of the human body, and the origins
of disease; 15 credits on technical basics inhealth, medicine, and welfare, and the scienceand technology of radiation; 17 credits on diagnostic imaging technology; 7 credits on radioisotope examination technology; 7 credits
on radiation therapy technology; 6 credits on
medical image information; 4 credits on radiation safety management; 2 credits on medical
safety management; 5 new credits on imaging
diagnostics; and the credits for clinical training
were increased from 10 to 15. The content of
the joint meetings between the national association and JART were reported to the national association in June. Unfortunately, the joint
report on the 105-credit proposal ̶ which
Special Feature ◆ 27

included new credits on imaging diagnostics
and 15 credits of clinical training ̶ became a
JART proposal. Keigo Endo, president of the
Kyoto College of Medical Science, which was
the new duty school, formed a group to reexamine the issue. This group then proposedthat 97 credits are sufficient. They eliminatedthe 5 credits we had allotted for imaging diagnostics and replaced it with two credits of“imaging diagnostic technology.” Over the last
15 years, the field of radiological technology
has grown both qualitatively and quantitatively. How is it possible to look back on these
15 years and only add two credits? These 97
credits will not be changed again for another 10 or 15 years. Is keeping a low numberof credits for such a long time really the best
way to educate radiological technologists forthe benefit of the public?
Concerning clinical practice, doctors aretransitioning from a primarily observationalmodel to a participatory model, and othermedical professionals are facing the same issue. I cannot understand how just two credits
is adequate for addressing the expansion andqualitative changes in our duties over the last
15 years.
I would like to discuss clinical training forother specialists, particularly physical therapists and occupational therapists. On May 30of this year, the topic of clinical training came28 ◆ Journal of JART English edition 2017

up before the Diet. The person who initiatedthe conversation was Toshiko Abe, a memberof the House of Representatives and the Japanese Nursing Association. She asked about theeducational objectives of clinical training forphysical therapists and other professionals.
The educational objectives of clinical training are to foster studentsʼ clinical observational and analytical abilities so they can address
an array of societal needs, possess the ability
to create treatment plans, and gain skills inreal settings. These objectives require a participatory model. Abe then asked about the
specific clinical training that physical therapists and occupational therapists receive fortechnical items that are not very invasive.
These involve using motions designed to help
patients recover basic movements like sitting
and standing to disease situations ̶ things
that certainly require participatory training.
She also asked about the qualifications of theteachers who conduct participatory clinicaltraining and about the instructional system. An
MHLW official replied that each training institution should have a two-to-one ratio of trainees to trainers. These are the kind of specificanswers that were given during questioning
in the Diet this May. All medical professionals
are being asked to change from observational
to participatory training. Currently, we have
10 credits of observational training. Even if wechange this to 10 credits of participatory training, who can say that it will be sufficient? If
we are going to do this, we need to increase
the training hours.
Do you know what is happening withother medical professionals? Massage therapists, acupuncturists, and moxibustion practitioners must currently take 77, 86, and 93
credits, respectively; after an MHLW study,
these numbers may increase to 85, 94, and100 credits. Even acupuncturists, moxibustion
practitioners, and massage therapists take 100
credits, and these professions are even thinking about further increasing their clinical train-

Three Policies and Issues Facing the Japan Association of Radiological Technologists

ing. The same changes are happening to judo
healing therapists. A newspaper article fromthe August 19 issue of the Yomiuri Shimbun
stated that judo therapists needed 85 credits
to graduate from training institutions 15 years
ago. Now, 99 credits are required, whichmeans that as the quality and quantity of ajudo therapistʼs duties increased over the last
15 years, 14 credits were added. How is it thatradiological technologists need just two additional credits in 15 years? I am always fighting for the profession, but this is something I
cannot accept. Even judo therapists added 14
credits over the last 15 years. However, afterreconsidering the matter, the new draft submitted to the national association only added
two credits. What is this? It is unbelievable.

5. Policy 3 – The shape the educational
system should take with an eye tothe future
Next is the third policy: the shape the educational system should take with an eye to the
future. The Radiological Technologist Law wasbrought before the House of Councillors in
1951. It was proposed by Yasaburo Taniguchi,
the then head of the Japan Medical Association, and was brought before the Diet by six

other lawmakers. At the time, it was decided
to have a two-year educational curriculum
consisting of 2,195 hours.
Based on this law, the two-year educational
system began in 1951. In the following year,
two-year programs were launched by Osaka
University and Shimadzu Roentgen Technical
School. A three-year system was proposed toand approved by the Diet in 1968. Three-year
programs started in 1968. These were governed by both the Medical X-Ray Technician
Law and Radiological Technologist Law, andrequired 2,985 hours of education. I have already discussed our duties back when we hada three-year system, which was mainly simple
X-ray imaging, as well as X-ray TV, angiography, radioisotope exams, cobalt therapy, andsuperficial treatments. However, our duties
have since grown. New diagnostic imaging
equipment for clinical use was developed in
the form of X-ray CT, and our jobs have transitioned from analog to digital with the appearance of methods such as PET, MRI, DSA,
and CR. Our work has expanded so muchthat we eventually began considering a fouryear educational system. Thanks to the hard
work of our predecessors, in 1983, the laws
were integrated under a single RadiologicalTechnologist Law. Along with integrating thelaws, they also thought four-year education
was something that needed to be implemented. Four-year universities and graduate
schools thus began to appear, starting in April
1987 when Fujita Health University launcheda program to train radiological technologists.
Suzuka University of Medical Science ̶ backthen, its name also included “and Technology”
̶ established a four-year university centeredon JART. As for the national universities, Osaka University launched a program in 1993.
Graduate school education began in 1996
with Suzuka University ʼ s course on medical imaging information, followed by Osaka
Universityʼs Division of Health Sciences in its
Graduate School of Medicine. Four-year edSpecial Feature ◆ 29

ucational systems thus spread and graduate
school programs were launched in both nameand reality. Looking at how our duties havecontinued to expand, in 1993, there was theappearance of MRI, along with ultrasonography, non-mydriatic fundus cameras, and confidentiality requirements; then in 2005, proton
beams, heavy particle beams, and neutronscame into the picture; in 2010, assisting withimage interpretation, providing explanations
and consultations about exams were included;
and in 2015, our duties involved removing
needles, stopping bleeding, lower gastrointestinal exams, nuclear medicine diagnostic
equipment, comprehensive instructions forchest screenings, and inserting tubes during
IGRT. If things continue in this vein, our education will become too broad for the scope ofa three-year education, and we will need toturn to four-year programs or even more studies.
In 2014, MEXT launched a problem-solving orientated training program for advanced
medical professionals, and sought participantsfrom educational programs around the country for research. The issue was related to doctors and dentists, in particular the lack of advanced medical specialists, the diversificationof societyʼs medical needs, and the changes
to dental and medical needs due to an aging
society. Our involvement has been in threeareas: promoting team medical care, strengthening ties between educational and clinicalsettings, and promoting regional medical networks. We need to pay particular attention
to developing pre-graduate and postgraduate
continuing education programs and to building a faculty development system, as well as
training instructors in the clinic and carryingout personnel exchanges between university teachers and instructors. Individuals whoteach in universities need at least a masterʼsdegree, so to have personnel exchanges withthese educators, the radiological technologists
who work in the clinic and oversee clinical30 ◆ Journal of JART English edition 2017training must also minimally have a masterʼsdegree.
In MEXT ʼs problem-solving orientated training program for advanced medical professionals, instructors from educational institutions
and clinical settings need to be on the samelevel in order to exchange views. In particular,
we need to improve educational programs infields that support biological function diagnostics (i.e. radiological technologists, clinical laboratory technicians, clinical engineers). Morehours are needed for education, and we needto build strong relationships between communities and universities. The people who areresponsible for the clinical training for 2,500
annual graduates nationwide minimally needa masterʼs degree, I think. I believe this will
become a major requirement for educationin our field. At this yearʼs general meeting,
I proposed a six-year educational system,
which was adopted by the assembly. Goingforward, four-year education should be seenas the minimum; we should also start looking
at masterʼs level education or six-year educational systems. Last year, the president of theJapan Pharmaceutical Association spoke about
the successes and problems with six-year
pharmacy programs. Our three-year programswith 95 or 97 credits are just not adequate forThree Policies and Issues Facing the Japan Association of Radiological Technologists

the times. Globally, Britain already has a profession called radiographer practitioners who
perform reporting. In the United States, thecourse to be a radiology practitioner assistantor radiologist assistant is 93 credits, whichallows them to assist in image interpretation.
In Japan, we are working with a system thatis about 15 years behind. I believe this ispreventing development in our educational
system and our profession. We need to lookat the matter of education seriously. As the
medical community develops, all specialized
professions, not just radiological technologists, have a growing number of duties. It is
not acceptable for just the profession to grow.
The educational system that guarantees our
profession is also extremely important. Looking at the history of our education, we started
in 1951 with a two-year educational system,
followed by three-year and four-year systems
in 1968 and 1987, respectively. Furthermore,
looking at what the current duties are, it
seems obvious that in order to train people
with advanced problem-solving skills, a sixyear educational system is needed. More thananything, we need to provide medical education that meets global standards. Therefore, I
believe the time has come for us to thoroughly reexamine how we conduct clinical training.
Japanese medical school graduates willswitch to a participatory model of clinicaltraining in 2023. If the current 51 weeks are
not increased to 72 weeks, degrees from Japan will not be accepted around the world.
The deadline for medical schools to meetglobal standards is 2023. Medical schools
in Japan currently provide an average of 51
weeks of clinical training. If this is not increased to meet the minimal global standardof 72 weeks, as of 2023, graduates from Japanese medical schools will not be accepted atforeign study destinations (places that accept
medical school graduates).
As medical professionals, we also need tolive up to global standards by switching fromobservational training to participatory training.
On this point, we have long required 10 credits of clinical training. To take these 10 credits
and move to a participatory model, it was
proposed to increase to 15 credits. Unfortunately, the national association did not deem
this necessary, and decided to retain the 10
credits. On top of this, we were told that thefruits of the last 15 years, quantitatively andqualitatively, mean we only need to increase
our education by 2 credits. Judo therapists
have added 14 credits over the last 15 years.
How in the world can this difference be explained? The development of our profession
is nothing if not for the development of oureducation. Our future depends on perfecting
these educational developments. I want thenational association group and professors atnational universities to clearly understand thispoint: I believe that the report I submitted to
the national association should be sent to the
MHLW for consideration. The next generationof radiological technologists will serve during
a time where chief radiological technologists
and radiological technologist professors willplay an active role. The chief radiological
technologists and technical department heads
Special Feature ◆ 31

at university hospitals around the country arepart of the university hospital mission to beinstitutes of care, education, and research.
Therefore, I would like chief radiological
technologists at university hospitals to at least
have a doctorate. Then, when they participate
in personnel exchanges with educational institutions, information from clinical settings canbe quickly communicated to the educational
arena. Professors as well, through exchanges
between themselves and with the heads ofclinical departments, need to usher in a new
age of education for radiological technologists. I would urge them to play an active role.
At the moment, we see a bachelorʼs degree asa matter of course. Please, do not be satisfied
with just a bachelorʼs degree. Get a masterʼsdegree. Furthermore, instructors should notstop with a masterʼs degree. Please obtain adoctorate and help generate evidence-based
data to submit to the MHLW. Unfortunately,
Approximately 30% of the instructors have
not yet a doctorates. I hope that all instructors will obtain doctorates so students canbe educated by professors with doctorates.

32 ◆ Journal of JART English edition 2017

I hope that chief radiological technologists
will strive to become department chiefs andvice hospital directors, and that leaders of radiological technologist departments will play
active roles within their hospitals. I hope thisage will come, and to get there, I believe weneed to develop a proper educational plan. I
have said some harsh things in this talk, but I
hope I have convinced you on this point. Let
us work together. Thank you for your understanding and support. I appreciate your courteous attention during my speech.
Chairman Yasuda: Thank you very much,President Yasuo Nakazawa.
Thank you for your report on the rapid response to the Kumamoto earthquake, and thedetailed description of the path our field hastaken since 1951. Regarding education, thankyou for your careful explanation on how we
differ from other professions. President Yasuo
Nakazawa has excellent teaching skills, andas the leader of Japanʼs 50,000 radiological
technologists, I hope he continues to play anactive role in our profession.

The 32nd Japan Conference of Radiological Technologists

Invited lecture

The Challenge of Teaching MRI
in the Future
Dr. Grey Michael Lee
Illinois State University, Associate Professor

Michael Grey:

My presentation today is about the challenge of magnetic resonance imaging (MRI)in the United States. As you know, there aremany areas of radiology, e.g., radiation therapy, ultrasound, nuclear medicine, vascularcatheterization; thus, there are different areasof radiology and medical imaging as a whole.
MRI is very new, whereas radiation therapy
ultrasound and nuclear medicine has been in
existence for many years. Thus, it was challenging to develop MRI in the United States.
Any program that is developed requires funding from a university and from the government to help to start the program. In the context of this challenge, I today want to discuss
program development, course development,
and how to go about setting up programs inthis respect.

In the beginning, MRI was not called magnetic resonance imaging. It was called nuclear
magnetic resonance imaging. Thus, the abbreviation was originally NMR imaging. Therefore, when, performing any kind of literaturesearch to prepare a paper or talk about anything historical, it will be necessary to searchusing the word ʻnuclear magnetic resonanceimagingʼ; not the abbreviation, but the entire

Historical Past – In the Beginning• Nuclear Magnetic Resonance Imaging (NMR)• Greater than 90% Brain and Spine• Musculoskeletal, Breast and Cardiac

1st commercially made MRI unit in the world
TECHNICARE NMR – 0.15TSpecial Feature ◆ 33

phrase. Using only “magnetic resonance imaging” will not include the very beginning of
the history. This is a picture of the system thatwas the very first commercially made unit in
the world. This is a 0.15-Tesla resistant unit
and this is me, back about 1984. This was thefirst commercially made unit and the company was called Technicare Corporation. GE
bought Technicare and thus Technicare nolonger exists, it is now part of GE.
In the beginning, many of the studies thatwere performed focused on imaging the brain
and the spine. We performed some musculoskeletal, some breast, and some cardiac,
imaging, but only very little. Additionally, inthe beginning, we had to introduce a brandnew imaging modality to the public. We had
to introduce a brand new imaging modality to
the world. Our facility was at the University of
Kentucky Medical Center, which has a greatbasketball team. Previously I have worked in
CT; trauma CT, routine CT, all aspects of CT.
Among the problems we had in CT at thattime was that patients would get sick if wegave them IV contrast. They would have nausea and may vomit. Therefore, many people
did not embrace the idea of undergoing a CT
examination because they expected that theywould feel sick.

the public and advertised the technique as involving nonionizing radiation that would not
hurt the individual. We also explained that itwas noninvasive, requiring no contrast agent,
as gadolinium had not been approved foruse at that time. It would still be a few more
years until gadolinium was approved for use
as an MRI contrast agent. We also advertised
it as having, excellent soft-tissue contrast, andtoday that is still true. Of all available imaging
modalities, MRI gives the best soft tissue contrast.
MRI yields no bone artifacts. Because weoriginally did so much brain and spine imaging, the doctors realized the benefit of
MRI, especially in the posterior fossa region,
which would be back in this area here, or inthis area here. There is no bone artefacts due
to beam hardening. Thus, the modality wasvery useful for looking at infratentorial-based
lesions. It also multi-planar imaging. We obtained axial, sagittal, and coronal images,
giving doctors a three-dimensional view ofwhere a lesion might be located. Thus, it wasvery good in brain and spine imaging. So,
these are – Some conditions, such as this is
Dandy-Walker syndrome was very easy to diagnose on MRI. This is agenesis of the corpus
callosum. There is no white matter connection
here.

When MRI became available, we educatedIN THE BEGINNING…
NMR Imaging Was ADVERTISED AS…
• Nonionizing• Noninvasive• Excellent self‐tissue contrast• No bone artifacts• Multiplanar Imaging

Agenesis of the Corpus Callosum
Dandy‐Walker Syndrome34 ◆ Journal of JART English edition 2017

The Challenge of Teaching MRI in the Future

We initially did much work to help introduce MRI to patients, to doctors, to communities around the world on a regular basis. I canremember people coming to our facility fromother hospitals and other universities. Manytimes they were from Japan. They would
come to the USA to visit our facility to comeand see what MRI was. It was an interesting
and an exciting time in my history.
Shortly after MRI started, several companies
begain to manufacture MRI units, shown inthis long list. Companies called Wang NMR
and Toshiba are still here today; Technicare
is gone; Siemens is still here; Shimadzu; Advanced NMR systems; Picker is no longer;
around GE; Diasonics; Fonar, still produce
today, (Dr. Damadian is President and CEO
of Fonar;) Elscint; Philips; and Bruker. Thus,
today there are fewer companies that are producing MRI machines. They have been bought
out and consolidated to where we have Toshiba, Shimadzu, GE, Philips, Siemens, which areprobably the main MRI machine manufacturers around the world.
Now, when I was working in MRI, I decided that I needed a new challenge. I enjoyedworking with patients, I enjoyed being inthe spotlight having people come by and ask
questions, but pushing the buttons began tobore me. I wanted something new to do andso I went back to school and I obtained my
Bachelorʼs degree in Health Science. There
was a very strong education content to that
Bachelorʼs degree. I then considered that both
MRI and are new, but there were no education programs for either as yet. I therefore
resigned as a technologist and moved to theuniversity at which I am based now, Southern
Illinois University. At that time we were transitioning from an associate degree, which was a
2-year education program on X-ray only to a
4-year baccalaureate (BS) degree. And in the
fourth year, the senior year, we were going toinclude advanced specialization such as MRI
and CT.
Now I donʼt know how many of you arefaculty professors, but at that time, there wasno MRI or CT program anywhere that I could
find to look at what courses were being used,
and what was being taught in class. I therefore had to consider what information should
be taught in a program on MRI and CT. I wastold to cover both modalities, which was apretty tough asignment. I decided to develop
four courses for dogmatic classroom instruction. There would be a CT Technology course,which would teach all aspects of CT. There
would be an anatomy course teaching normal
anatomy. There would be an MRI technology

Special Feature ◆ 35

course, covering all aspects of MRI, and thenthere would be the pathology course for CT
and MRI. That was the one area for which I
could not find a textbook or any informationthat was written for technologists that would
help them to learn and develop their skills.
The first problem in the course work wasfinding textbooks that the students could use
to read, to lecture from, and to make the program feel more like program. Remember thatat this time, about 1996, nuclear medicine,radiation therapy, ultrasound, and radiology
were very well, but MRI and CT were not.
Thus, it was a challenge to get approval to
begin a program such as this. One of the challenges was helping to produce the textbooks
for the students. This is me with my very firstbook; it is on display with the publishingcompany McGraw Hill here. This was a big
accomplishment. Later on the first edition ofthat book would be translated into Japanese.
The second edition was translated into Russian. Currently, I am working on a third edition. With each edition, and the number ofcases that will help the technologist to growand be able to discern the difference between
normal and abnormal structures has increased.
Now, the next challenge was in the program that I described earlier: CT technology,
MRI technology, sectional anatomy, CT/MRI
pathology, which was designed to provide an
introduction of MRI and of CT at an entry level. However, MRI technology has advanced.
We now have higher field strips, we have abetter gradient system, we have a better RF
coil, and we have better software. Thus, wehave the ability to perform a greater variety of
examinations today than in the beginning. In
the beginning, over 90% of our studies wereof the brain and spinal cord, but this is not
the case today. Today, we see many musculoskeletal studies, we see cardiac, vascular,
and breast imaging; there is a wide variety of

36 ◆ Journal of JART English edition 2017

examinations being performed today. Hence,
when developing a career path or career ladder, this was something that I think professors
need to think about. They need to monitor
the growth and the variety of examinations
that are being performed maybe in their countries. We do in our country, as I will show.
This allows one to use that data to help guideprograms for developing a career ladder.
MRI has advanced markedly, so that MRI
can do many things today that could not bedone originally. We therefore need to stay
current and keep up to date with the types of
examinations that are being performed. I am
going to show you that in just a little while.
We also need to consider what changes are
occurring in MRI. In my life, there has been
many changes in MRI; that has only been overthe last 35 years. As professors, we need to beaware of those changes and how to integratethem into our program, or consider the needfor two levels in our program a beginner level
and an advanced level.
We also need to think about the new trends
in imaging. Here is an example of something I
found very fascinating. This fracture is termed
an occult fracture. Does anyone know what
an occult fracture is? You cannot see this typeof fracture on a basic X-ray. Years ago, thedoctor would have said, “You should undergo
a nuclear medicine study.” The patient would
then have to be injected with a radioactive
isotope, and would have to sit for a long period of time, but the image would not be nearly
as good as this is. Thus, in current practice,
the trend is that a patient with a normal X-ray,
but with continueing problems should undergo an MRI, without contrast, gadolinium,
radioactive material, or ionizing radiation. The
patient simply undergoes a study and leaves.
Thus, the way in which we order studies onpatients has changed to improve the outcome.
This is a very interesting and good example

The Challenge of Teaching MRI in the Future

The Challenge:
Developing the Career
Path for MRI
Technologists
Keeping current … and Keeping up to
date…
• What changes are occurring in MRI?
• What are new trends in imaging?

FIGURE 2. Fracture of the Medial Femoral Condyle. STIR coronal MR
image of the knee (same patient as in Figure 1 ) shows an obliquefracture of the medial femoral condyle as high signal.

of use as things change and why they change.
This highlights the need to monitor thesetypes of changes as they continue to occur.
Here is the challenge in teaching MRI. Today, we need to think about the career pathof our students, and our technologists. We
need to think about how to advance from theintroductory level. In the United States, formal
education about MRI or CT is not required,unfortunately. The manufacturer will teachthe technologist to push various buttons, but
no formal education is given. However, weare dealing with a piece of equipment that isvery expensive and can have a vast impact
on patientʼs lives. Do you know patients who
have been injured during MRI in your country? Have you ever heard of a patient being
injured during MRI? What about a patient who
was killed during MRI, who died from MRI?
Do you know?
In my country, I do medicolegal work. I
review cases about people who have been
hurt or killed. I do not advertise. They findme. I review cases and I consult. Two years
ago, MRI death should not have occurred.
However, it is very unfortunate that there is
no formal education on MRI given in the US.
Nevertheless, we have a program; students
can choose to come or not. I am glad when
they do. To go to the next level, the advanced

level, we need to think about many things.
We need to consider what types of skills will
be required to do the new procedures, theadvanced procedures. What type of education
will be required? Will it be formal classroom
education? How should this be done in a hospital clinic setting? We need to think about
what are our goals, what are the values ofaccomplishing this task, where is the interest,
what type of doctors, and what type of facilities will benefit from this type of education?
How should we develop these courses?
There is a need for experts in education,
content, and subject matter to write the objectives, to write the instructions, to write thetest questions, as well as for professors who
understand the content, have experience, andcan teach in the correct way. Finally, we needto consider professional growth, involving the
introduction, beginning, and then advanced
level. We need to think about how to proveand verify the change, the trends, and how to
support a proposal for advanced education.
This could involve a job analysis. It is also
called practice analysis or a needs assessment.
It is useful to consider and monitor what
technologists do in your hospital, as this canbe used to determine the type of educationand training support that is needed. If a higher number of examinations are performed, itSpecial Feature ◆ 37

Job Analysis & Needs Assessment• Used to determine:If education / training is neededCause of poor performance
Content & scope of education & training
Desired outcomes & measurement
Gain management support

could support the need for a program modification. If technologists perform poorly because they do not know the anatomy, andthey do not know how to perform a study,
other than simply how to push buttons, education and training could support that. Whatis the content and the scope of the educationand training that needs to be done? This has
two facets. Education is formal instruction in
the classroom. Training occurs in the hospitalenvironment, working with other experienced
people, such as radiologists, physicians, andother technologists, gaining hands-on experience in proper sequencing. At my university,
I do all the coursework first and then when
the student goes into the hospital setting, theyknow everything about technology, pulse
sequences, patients screaming, and contrast
agents. They therefore merely require experience in how to position the patient and perform the studies. Thus, in their 3 week rotation, they constitute extra help, and thus, thehospitals really like the students.
Therefore, at what should be included in
the program. What topics are best discussed
in the classroom? What topics are best dealt
with in the clinic setting. Once we know
and this, we can set assignments, objectives,and questions that support this. In the United States, we are collecting much data on
outcomes, where we have to do program

38 ◆ Journal of JART English edition 2017assessment. The administration looks closely
at program assessment, where we look at thestudents coming in, the students exiting, and12 months later. We consider whether they
are working as MRI technologists and if so,
what their employer thinks about their work.
We have to submit all this information to ouradministration on a yearly basis. In such program assessment, we determine where there
is weak area, to try to improve and strengthen
the program. We also need to obtain the support of management. If my management, myadministration, and the hospitalʼs management
are all working together in teaching the medical students, we have a win-win situation.
It should be considered whether the hospital needs such a program, and whether the
studens require such an education. This is theconcept behind doing a job analysis, practiceanalysis, or needs assessments. For my doctorate, I used data obtained by the American
Registry of Radiologic Technologists. They
needed a subject matter expert, and contactedme, saying, “Hereʼs data. We donʼt know what
to do. Could you look at the data and help us
to decide?” This is what I then did; I based mydoctorate research on that data, and I wrote
an article and submitted it to our professional journal in the US, Radiologic Technology,
and it was published. Here is the title. It wasa preliminary study, the very first one ever

The Challenge of Teaching MRI in the Future

done, and this was something that I think thatprofessors and faculties should consider.
I see many people, such as technologists
doing clinical research. In our country, medical doctors do the clinical research. They havethe authority to say what is good and whatneeds to be changed. In terms of education, I
should focus on education research. This was
the first study that I know of that consideredadvanced level MRI. We had done a survey
much earlier that was published to support
only the introductory level, which had been
performed around 1996. From that study, I
was able to identify that there were some specialty areas. We saw a large number of examinations being performed in those areas. If I
were to put this together into what could be acourse, I would call one course Cardiovascular; it would deal with the heart and heart coronaries. I would call another course, central
nervous system imaging; this would more include doing functional MRI, MR spectroscopy,
diffusion tensor imaging, and fiber tracking,in the brain. We see those areas growing. I
think technologists need to be better educatedin those areas. The third area would involve
everything else. Thus, in body imaging, focus
in greater detail on musculoskeletal imaging,include breast imaging, do more vascular imaging, and more abdominal pelvic studies. We
cannot teach everything about MRI in an introductory level course; it is necessary to separate the introductory and advanced levels.
It is therefore necessary to decide whatshould be included in the basic introductory
course and what should be included in theadvanced level. In doing a task analysis, theintent is to begin a program and use a task
analysis to help implement or start it. Items
to consider when developing your survey isidentifying the various types of examinations
that are performed. Those could be the tasks
that are set. In identifying these tasks, thefrequency with which, you want to look atthese examinations are performed should beconsidered. In the US, some hospitals havean MRI unit for performing cardiac imaging
only; other hospitals do no cardiac imaging,and yet other hospitals do, a little bit of cardiac imaging. Thus, while we can do cardiac
imaging, not all places do cardiac imaging.
In our healthcare system, the insurance companies do not reimburse for cardiac MRI although they reimburse for cardiac CT. There
are therefore other issues that come into playhere.
In addition to frequency, what is the importance of such a study? For example, althoughreimbursement is more likely for cardiac CT
than for cardiac MRI, it is still necessary torecord how frequently these studies are performed. Similarly, how frequently is breast imaging performed? In musculoskeletal imaging,what is the most common joint that is imaged;
is it the shoulder, elbow, or wrist? It is most
likely the shoulder. In the lower extremities,
is it the hip, knee, or ankle? In the US, it is
the knee. Besides recording frequencies, we
also need to develop a scale of difficulty.
How difficult is it to perform the procedure?
Is it low, medium, or high difficulty? Some
MRI procedures are easy to do, while someare very challenging and much more difficult
to do. The more difficult procedures may require more time for teaching while those thatSpecial Feature ◆ 39

Task Analysis … to … Implementation• Frequency• Importance• Difficulty• Performance standard

are easy may require less time. In addition, aperformance standard is needed. How goodshould the study be? Ideally, we would want
the study to be perfect. However, as this is
implausible, we require a standard that determines the requirements that a study shouldmeet in order to pass, and for the education
to be good. In each type of task, it is necessary to identify the knowledge, skills, andabilities that should be acquired.
What does a technologist need to know,what do they need to know how to do, andare they able to do it? When you include
these three things into the writing objectives,it allows evaluation of each student, on theirknowledge, their skills, and their abilities.
Thus, these items help us with our assessment
program. We therefore see the beginning and
we see the end, and then 12 months after
graduation, what does their employer, their
manager, their director think of them? It is important to monitor whether they are satisfied
or not and whether there is an area in which
they see the need for improvement.
Now, in the United States, a company, IMVinfo.com, track data including data on thegrowth in MRI sites in the US. It is very helpful to managers and administrators to have avast amount of data to help them make decisions on trends, or even to help them in buy-

40 ◆ Journal of JART English edition 2017

• Knowledge• Skills• Abilities

ing a brand new piece of equipment. Thus, inlooking at the data in some years, in 1998, forexample, there were over 4000 MRI units in
the United States in 1998. In 2004, there were
almost 7000, indicating a steep growth in thenumber of MRI units purchased. In 2007, thenumber dropped a little bit. Today, the mostrecent data for 2015, shows about 8500 MRI
facilities in the US. Some hospitals have two,some have three, some have four. Not all hospitals have MRI, very small hospitals have no
MRI. Nevertheless, we observe a growth in
the number of MRI units from the beginningto the present day.
Likewise, we see growth in the number of
MRI procedures that are performed. Starting inthe same year, 1998, about 12 million examinations were performed, and this number has
grown; in 2015, about 38 million procedures
were performed in the US. What can one tellan educator in a university about the needs oftechnologists working in MRI? The technologists workforce is predicted to show a mean
increase of almost 25% between 2012 and2022. Therefore, the type of data I have been
investigating and data on other trends shouldbe put together into a proposal to submit to
the administration, as something needs to bedone to meet the needs of the field. If I simply go to my administration, and I sit down
and talk to them, and say to my Dean, “WeThe Challenge of Teaching MRI in the Future

Workforce Preparationneed to develop our program further”, theyʼll say, “Why? Where is the proof? Why should
we do this?” Talk alone is insufficient. You
need to have the data that support what you
want to do to help meet the needs of the people in your nation. Therefore, having accessto that information is excellent, and when you
do not have access to it, then you have to be
the person that goes and gathers it.
The company shown here is only for theUS, but you could put together a survey anddo your own study for your country. You
then to write that up as a manuscript for publication in a journal, to make it a record of
history. We predict the needfor an increaseof almost 25% in the next few years, for MRI
technologists only. We also see a need ofabout 20% for x-ray and MRI combined. All
students that participate in my program, havealready been trained and accredited in X-ray.
The have already been through the basic radiology program; now they come into theadvanced level, MRI and CT. By the time they
have done three credentials, i.e., X-ray, MRI,
and CT. They are very remarkable, and theyusually have a job before they leave the program, which pleases me. It looks good on theassessment report.
So, this comes out of a federal organization
called the US Bureau of Labor Statistics andeven though this is probably pointed projection, the word “projection” means they consider that there will be this type of need infuture. We can use this type of data to supporta change today for what is being looked at in
the future, which is very helpful. Here again,
when you would do a study in your country,
that kind of gives an overview of what typeof procedures are performed, how frequently
those procedures are performed. Next, you
should write that up and submit it to a journal, a professional journal, for publication.
You could be the first for your country maybe. Work with your government, work withyour professional society. For me, emerging
specialty areas in MRI and the initial study. If
someone 10 years from now is doing a study
on education trends in MRI, if they are doing
a search for literature review, it will take themto the Radiologic Technology journal, andtheyʼll see my work there. So I will encourage
you to do these types of studies, write themup, and submit them for publication. Manytimes, professors, managers in different areasof medical imaging need to work for promotion, to climb the career ladder. This is a very
good way of helping you obtain publications,to help with presentations, to share what goeson in your country. So, I have read a little bit
about some of this in other countries but notvery much in all the countries in the world.
Special Feature ◆ 41

So think about this and sharing what goes onin your country. It can also be beneficial in
doing time course studies. Was there growth?
Was there change in trends? So it can be very
helpful in your nation.
And when I was here in April, I was introduced to your journal here in Japan and I wasvery excited that there is an English version
I would be very interested in working witha professor here in Japan if he would like tocollaborate and write a manuscript and submit
it for publication. I think it would be good.

Emerging Specialty Areas in MRI Imaging:
An Initial Study

1. Cardiovascular Imaging
2. Central Nervous System Imaging
3. Body Imaging

42 ◆ Journal of JART English edition 2017

It would be good for both nations and very
good for professional status. This is from myvisit in April and again Dr. Osawa and Yasu,
who took care of me, getting me from theairport to the train station to my hotel to thismeeting to the train station back to the airport, I cannot thank you enough. I appreciate
all the help that they gave, I had a very good
visit in April, and very good visit this trip here.
So I am very thankful for my friends in Japanand on this trip here meeting other friends
that I have not seen in a few years from othercountries, Taiwan and Singapore and Macau,

The Challenge of Teaching MRI in the Future

Thank You!

Questions???

I am very thankful to my friends from othercountries.
Even though I am from the US, we share
a common interest, medical imaging. Thus,
brothers and sisters in the healthcare fieldwould like to say thank you and if you haveany questions, I would like to take thosequestions now. Thank you.

Chair Person:

Thank you so much Dr. Michael. Today,
you delivered a very good lecture. Thank you.
Iʼd like it for Vietnam.
Michael Grey:

Vietnam, thatʼs right, yes.
Okay. Thank you. Thank you very much.

Special Feature ◆ 43

Hospital Introduction andCurrent Status of Regional
Healthcare with Progressing
Depopulation
Kensuke Ehara
Hokkaido Association of Radiological Technologists Wakkanai Branch
Esashi Hospital

Introduction
My name is Kensuke Ehara and I work in
Esashi town in the Souya region of Hokkaido.
Esashi Hospital where I work in a secondary
emergency medical institution, which performs clinical services; it has83 beds (general
beds: 46, long-term care beds: 37), and clinical departments that include the Department
of Internal Medicine, Department of Cardiovascular Internal Medicine, Department ofSurgery, Department of Orthopedics, Department of Pediatrics, Department of Psychiatry,
Department of Neurosurgery, Department of
Gynecology, Department of Ophthalmology,
as well as 17 beds for artificial dialysis (including isolation). The current equipment for the
Department of Radiology includes a generalimaging device, x-ray TV, angiography equipment, 64-slice CT, 1.5T MRI, MMG, DEXA, US,
and WS. As a local government-run hospital,
we are fortunate to have a favorable environment in terms of equipment and facilities.
There are currently three radiological technologists.
In 2006 Esashi was amalgamated with the

44 ◆ Journal of JART English edition 2017neighboring Utanobori town. In the ten years
since the amalgamation, the population has
decreased by 1,500 people, and the current
population is approximately 8,500 people.
The region faces the Sea of Okhotsk and has
an area of 1,115 km2, making it the ninth largest local government region in Hokkaido. In
Hokkaido there are two Esashis: there is one
located in the Donan Hiyama Subprefecture,
which is well-known, but our Esashi in the
Dohoku Souya region is very obscure. The
main industries are fishing and dairy, and the

Wakkanai (120 km)

Esashi-cho
Monbetsu (95 km)
Nayoro(approx.
90 km)
Asahikawa(approx. 160 km)
Sapporo(approx. 300 km)

town has a particularly large catch of hairy
crab and salmon. Distances from typical cities/towns are: 300 km from Sapporo, 160 km
from Asahikawa, and 90 km from Nayoro
where the nearest general hospital is located.
Thus we are separated by distances unthinkable anywhere else in Japan but Hokkaido.
Public transport consists of intercity buses.
There is one round-trip bus to Sapporo oncea day (the journey takes 5 hours), and tworound-trip buses to Asahikawa a day (thejourney takes 3.5 hours). There is no railway
line in the town (discontinued in 1985), andthe nearest railway station is the JR Otoineppu
Station, which is approximately 50 km away.
Currently there are three direct express trains
to Sapporo a day, but it is uncertain how long
this will continue, which is making residents
living along the train line anxious. If driving
toward Sapporo or Asahikawa the Hokkaido
Expressway is used, but the nearest entrance
to the expressway is 110 km away at the Shibetsukenbuchi interchange. However, Esashi
is not an especially remote region; I would saythat all regions of Hokkaido are in a similar
situation. For me, born, raised, and employedin the southern district of Saitama, Hokkaido
was very desirable, and 18 years ago I madeup my mind and moved here. While living fora number of years in a number of towns in
Hokkaido I was astounded at the uniquenessof the local healthcare in Hokkaido; thus I
started working in Esashi with the feeling that“when embarking on a great project, start withsmall steps.” It has been 15 years since I cameto Esashi. Now, I would like to give my personal account of my impressions of workingin Esashi, which is so remote from an urban
area, and where there is progressive depopulation.

grounds were opened under the direct controlof the Matsumae clan. In 1878 with the declaration by the Hokkaido Development Commissioner there were four villages established:
Esashi village, Utanobori village, Tonbetsu village, and Rebun village. After that time there
was enforcement of village amalgamation,
separation and reorganization, and the current
conditions were subsequently reached in 2006
when the former Esashi was amalgamatedwith the former Utanobori (from Esashi-cho
history).
The population peaked in 1960 at 18,541
people but has since continued to decline. In
2015, the population was 8,500 people, making Esashi the epitome of a depopulated area
(Fig.1). The number of households has notchanged very much but shows the progression of the nuclear family, with approximately 4,300 households at the peak and around
4,000 households at present. When we compare 1960 and 2015 in terms of increases anddecreases by age group, there has been a 53%
reduction in population while there has beena 255% increase in people aged 65 years andolder; the 15 – 64 age group has decreased by
56% while the 0 – 14 age group has decreased
by 85% indicating a rapidly progressing aging
population combined with a low birth rate(from Esashi population vision).

Changesin Esashi
population
Total population≥ 65 years
15 to 64 years

Esashi has a comparatively long history
within Hokkaido, and in the 1680ʼs fishing

2010

2000

1990

1980

1970

About Esashi

1960

0 to 14 years

Fig.1 Changes in Esashi-cho population
Special Feature ◆ 45

There is only one hospital in theregionWhen I was employed by Esashi-cho, thepeople in the town kindly and warmly welcomed me and, needless to say, so did thehospital employees. My worries that outsiders
would not be well-received were unfounded.
There are many employees and residents who
move here from outside the town and fromoutside Hokkaido, and almost all the current
clinical radiological technologists, clinical laboratory technologists, and clinical engineers
are originally from places other than Esashi.
The first thing that surprised me when I
moved to this town was that people cannot
choose their own hospital. Until a few years
ago, there was a private health clinic but it
was closed because the physician was very
old. For me, who had been accustomed tohaving the option of going to hospital A for
this illness, going to clinic B for that symptom, going to a duty hospital if something
happened outside hours, I had never considered that people would not have a choiceof different medical institutions. However,this hospital is responsible for all outpatientsduring the day, after-hours treatment during
the night and on holidays, and emergencies.
After the amalgamation of local governments
Esashi ended up with only one hospital andone clinic, but this is only a transitional measure. There is the opinion that only one hospital should be enough owing to the depopulation, and there may also be some people
who think that having one hospital is better
than nothing, given the remoteness of thetown. All the towns and villages that makeup the Wakkanai Association of RadiologicalTechnologists are in the same situation, with
one hospital for one local government area.
The patient flow is often to the local hospital, to the Wakkanai city medical institution
if they live in northern Souya/Rumoi, or the
medical institution in Nayoro if they live in46 ◆ Journal of JART English edition 2017

southern Souya, and as decisions are madebased on distance rather than on the available
clinical departments, it is rare for patients tocommute to a hospital in a neighboring town.
Almost all the patients are local residents, andI was surprised by the high rate of encountering acquaintances. It is 90 km to Nayoro
City General Hospital from Esashi, and 120
km to Wakkanai City Hospital. Half the year
studless winter tires are required, and there isdaily compacted snow ice burns. Frequently
this region also has drifting snow which hampers visibility. For the town residents who arebecoming increasingly more elderly, commuting to hospitals over long distances in theirown cars is very difficult, so they must relyon their local hospital. However, for patients
who need the departments of dermatology,
ear, nose and throat, or ophthalmology, it isa 180 km round journey to the hospital in
Nayoro and a round journey exceeding 300
km to the hospital in Asahikawa. This hospital is attempting to provide treatment to suitthe needs of the local populace, but on days
when there are no doctors deployed to thevarious clinics, and after hours, the regular
doctors treat all the patients.

Shortage of doctors
When I came to Esashi there were five fulltime doctors. This number decreased over theyears and four years ago it became two doctors. From April of this year we gained one
doctor, so now there is a three-doctor system,with two cardiologists and one surgeon. Outpatient clinics other than internal medicine,cardiology, and surgery are dispatched from
Asahikawa Medical University Hospital andNayoro City General Hospital, and we also
request visiting care from hospitals in Sapporo
and Asahikawa (Table 1). After-hours treatment at the weekend and emergencies arealso requested of visiting doctors in the same
way as the outpatient clinics. We are foreverHospital Introduction and Current Status of Regional Healthcare with Progressing Depopulation

Table 1 Number of days with visiting
outpatient clinician
Pediatrics

3 days / week

Orthopedics

1 day / week

Gynecology

4 days / month

Gastroenterology

2 days / month

Neurosurgery

1 day / month

Ophthalmology

2 days / month

Psychiatry

1 day / monthgrateful to these doctors, who travel vast distances to our hospital.
Esashi-cho is located within the southern
district of the Hokkaido Government Souya
General Subprefectural Bureau, and even in
Wakkanai City Hospital in Wakkanai, which is
the only city within the jurisdiction of Souya,a shortage of doctors is not unusual; there isalso closure of clinical departments, and staff
are beginning to find it difficult to accommodate patients from this hospital. Therefore, interms of medical districts, secondary to tertiary
treatment is requested of Nayoro City General
Hospital, which belongs to the Kamikawahokubu district, but the acceptance system to
the Nayoro City General Hospital is becoming
stricter, and it is not unusual for patients to betransferred to medical institutions within Asahikawa over 160 km away from this hospital.
If there should be 200 doctors for every
100,000 people, then there should be 17 doctors for this town with a population of 8,500
people…
In Esashi-cho there was a change in the
medical care system with the appointmentof a cardiologist in 2005, who is the current
hospital director. In 2006 MDCT and AG wereintroduced, which made it possible to diagnose and treat cardiovascular conditions, andthen in 2009 one cardiologist was appointed
to the hospital. There were originally eight
beds allocated for dialysis, but the number ofbeds was increased to 17 to meet the needs ofthe local community, and the cardiologist can
now deal with shunt problems with a shunt

PTA. We now conduct around 100 coronary
artery CT scans and cardiac catheter tests per
year. In this town that has always had a highsalt diet, there is a large proportion of patientswith cerebrovascular disease, so we requested
the introduction of an MRI machine for proper diagnosis and transport of patients to neurosurgical departments. In 2011 we were able
to introduce our desired MRI machine. Since
the retirement of the previous hospital director, who was a gastroenterologist, the uppergastroenterological examinations, which werepreviously implemented as endoscopic examinations, were almost all replaced with gastricbarium examinations and 200 to 300 of these
examinations are performed each year. Twoyears ago we managed to secure a visitingendoscopic specialist two days a month, so
not only have endoscopic examinations been
revived, we can now also perform ERCP, EST,and EBD using the x-ray TV equipment (updated FPD in 2015), which had been used forbarium examinations.
The regional cooperation system (Northern
Dohoku Medical Cooperation Network System: Polaris Network), which shares treatment
information and imaging data during emergencies, has been running since June 2013,
and we participate in the network centeredaround Nayoro City General Hospital. The
hospital has also benefited greatly from thissystem. Not only has the overburdened emergency transport been reduced, we are also
now able to seek the accurate instructions ofexperts. A remote radiogram interpretation
system was also introduced in this hospital,
and we are endeavoring to improve the accuracy of image reading for general treatment
and medical checkups. Looking over the pastfinancial year, the Esashi-cho healthcare system was overwhelmed with an average of 200
outpatient treatments per day; if emergencies
came in, they were also treated, while also
coping with wards running at 80% capacity.
Once or twice a week the regular doctors are
Special Feature ◆ 47

Table 2 Number of patients（FY2015）
Total number of outpatients
Number of clinic days

21

18

22

22

21

17

21

19

20

18

20

22

241

Total

Clinical department

Apr

May

Jun

Jul

Aug

Sept

Oct

Nov

Dec

Jan

Feb

Mar

Internal medicine

1,620

1,526

1,667

1,761

1,227

1,675

1,650

1,561

1,630

1,460

1,595

1,768 19,140

Psychiatry

106

107

128

127

137

162

135

147

144

133

142

136

1,604

Cardiology

559

543

602

648

537

654

622

568

663

599

592

655

7,242

Pediatrics

243

259

290

166

144

240

327

585

596

250

255

239

3,594

Surgery

987

799

1,022

821

933

924

1,044

1,207

1,129

917

1,163

Orthopedics

219

178

212

256

197

242

249

237

212

214

234

248

2,698

Neurosurgery

30

34

25

38

23

32

32

37

34

29

31

37

382

Gynecology

43

49

37

51

39

31

39

62

47

38

32

45

513

91

1,107

Ophthalmology

50

86

146

46

81

105

112

97

98

92

103

3,857

3,581

4,129

3,914

3,318

4,065

4,210

4,501

4,553

3,732

4,147

972 11,918

4,191 48,198

Mean number of patients per day
Number of clinic days

21

18

22

22

21

17

21

19

20

18

20

22

241

Apr

May

Jun

Jul

Aug

Sept

Oct

Nov

Dec

Jan

Feb

Mar

Total

184

199

188

178

158

239

200

237

228

207

207

191

201

on call ─ I think there are some doctors who
are on call even more frequently ─ so we are
only able to stay afloat with the support of
doctors who travel long distances as visiting
clinicians (Table 2).

is that young people tend to be lured by big
cities. Moreover, as there is no mid-sized orlarge hospital potential nearby, candidates areprobably concerned they will be left behindby the ever-advancing medical technology.
Furthermore, as this hospital is the only hospital on emergency notice (designated as secondary medical care), one of the reasons fortheir hesitation is probably that they would
be called in to work irrespective of whether it
is at night or on holidays. However, there are
few tests conducted outside of normal hours(Table 3), and the current topic of the oncall system shifting to a two-shift system or athree-shift system is a problem of different dimensions.
We are on duty every day, even on weekends; we are on duty day and night, so weare basically on duty all year round. Even if
there are only a few tests, the expectationthat we may be called in at any time is continuous day in and day out. The best thing

Shortage of technologists
This hospital became a three-technologist
system (one assistant) a number of years ago.
The previous head technologist who retired
because of age limits operated the system
alone for approximately 20 years. After that I
was employed and a two-person system wasin place for ten years or so; currently, there
are three technologists. Almost all Esashi-choʼsneighboring towns and villages operate with
only one technologist, and even if positions
are advertised there are few technologists willing to relocate to the regional area (known as
the backcountry). I believe there are various
reasons, but the first reason to come to mind

Table 3 FY2015 Number of outside hours tests
Test month

Apr

May

Jun

Jul

Aug

Sept

Oct

Nov

Dec

Jan

Feb

Mar

Total

Outside hours（cases） 30

48

33

39

48

40

50

24

42

32

55

54

495

48 ◆ Journal of JART English edition 2017

Hospital Introduction and Current Status of Regional Healthcare with Progressing Depopulation

about having three technologists is that weare able to rotate our on-duty times. There
are some regions that do not recruit a second
clinical radiological technologist owing to thesmall number of tests and small variety of machines. I love my job as a clinical radiological
technologist; I also feel comfortable with the
responsibility that I (we) am the only radiological technologist in the area, and I certainly
do not feel discontent at being on duty, butsometimes this degree of constraint is wearisome. In most cases, if I attend lectures ortraining sessions I need to stay away overnight although it does depend on the distanceand the transport situation. When I need to beaway from the region, I make arrangementsfor other technologists to be on duty. Sometimes I can ask the clinical radiological technologist, who retired in the local area to takeover, but if it is not convenient then I must
request the dispatch of technologists myself,
and oftentimes I am unable to make thesearrangements. I often need to cancel my engagements because, despite searching among
my personal friends and acquaintances, I am
unable to locate a replacement. I usually makerequests for replacement technologists to
those who live in cities where a large numberof them work; however, they need to travel along distance, and they use their own cars, so
accidents while they are in transit are a constant worry ─ in addition to normal traffic accidents, there are frequent collision accidents
with Ezo deer on Hokkaido roads. Then, even
if I have the good fortune to have a technologist dispatched, in addition to taking images, my job description has recently come toinclude operations that are hospital-specificand machine manufacturer-specific, including
HIS/RIS information system operations, image
processing after taking an image, etc., which
creates new problems. Therefore, I am always
thinking that we should be able to build adispatch system like that seen in other occupations ─ if anyone has any examples of suchoperations, I would love to see them.
It is not that every day is so busy that I am
constantly taking images… and patients are
not forced to wait for hours on end in one
modality, but there are more machines thantechnologists, so I am often engaged in work
running from one machine to the next, andsometimes I am nostalgic for the old machines
where testing took time. I manage with myworkload because not all clinical departments
are treating patients constantly, but if there
were more doctors working and orders coming in from multiple clinical departments, I
would probably not be able to cope with theworkload. Rather than making sure there aresufficient numbers of technologists despite ashortage of doctors… the shortage of doctors
ensures that even with a shortage of technologists it is possible to work through the dayʼs work without a backlog. As stated in the
Shortage of doctors section above, there areclinical radiological technologists and testingmachines even in regions where depopulation
is progressing, so if preparations are made referencing courses in association with journals
and allowing doctors to participate in training
courses held by the Japan Association of Radiological Technologists, then it would possible to supply standard tests simply by having
a doctor attend these courses.
I am often asked for advice about the test
results and I often offer my opinions on thesematters, so this constant interaction with doctors is also thanks to the shortage of doctors.

Appeal of the local area
I have only described the negatives of thelocal area, but I love this town. Half of Esashi-choʼs scenery is the sea, while the otherhalf is mountain forests, the sun and the moonrise from the horizon, the stars are bright atnight, the inland temperature in the summer
exceeds 30 °C, while in the winter it falls below -30°C. Even along the coast, temperatures
Special Feature ◆ 49

Esashi Hospitalof -20°C are not unusual. Ice floes come close
to the coast, and sea angels (Clione) also
make an appearance (they can be captured
and admired). Once the ice floes retreat andthe sea is accessible again there is a wide
range of delicious seafood on offer, ranging
from hairy crabs to sea urchins, whelks, octopus, scallops, herring, flounder, salmon, trout,and mackerel. Unfortunately, I have an allergy
to crustaceans and cannot eat crab. There are
as many mountain vegetables and mushrooms
as one can eat, and encounters with brown
bears and Ezo deer, and the Stellerʼs sea eagles and white-tailed sea eagles that fly above
the mountainsides along the coast are notuncommon. There are no railway lines, expressways, or tall buildings, but there is a vast
sky with clear air and no noise. For a while
after I moved here the nighttime was so quiet
it frightened me so I slept with the television
on. There is also a cellular phone base stationand internet environment. It would be a lie
to say that I do not notice the inconveniences of living in Esashi, but there is more thanenough appeal to offset the inconveniences.
Despite saying this, there is no tourism office,and people visiting Hokkaido almost always
simply pass through while traveling up thecoast, but this place is appealing because it
is increasingly depopulated and is retaining
its natural beauty without becoming a tourist
attraction. Of course, this is not limited to Esashi, or even to Hokkaido ─ there are many

50 ◆ Journal of JART English edition 2017

areas of beauty in all regions of Japan. If you
have the qualifications and skills of a clinicalradiological technologist, then you can move
anywhere there is a hospital. To all the people
working in regional areas of Japan let us work
hard together with our local communities, andI hope that we find the ideal land that local
regions are aiming for …

In conclusion
I would like to express my heartfelt gratitude to Yasuo Nakazawa, the president of theJapan Association of Radiological Technologists, for coming to Wakkanai in the northern end of the country and giving me thisopportunity. I am also grateful to Shun Mori,the director of the former Tokyo Associationof Radiological Technologists, who took thetrouble to hold a Wakkanai special lecture for
President Nakazawa.
Thank you also to Michio Bando the chairof the Hokkaido Association of RadiologicalTechnologists, director Nobuo Tomita, director
Fujihiro Akitaya, Yuichi Sekito the vice chairof the Sapporo Association of RadiologicalTechnologists and Toshifumi Goto the chair of
the Tokachi Association of Radiological Technologists, who provided their cooperation and
who all traveled over 300 km to attend thislecture.
Thank you to the clinical radiological technologists at the Nayoro City General HospitalHospital Introduction and Current Status of Regional Healthcare with Progressing Depopulationand Shibetsu City Hospital, to whom I am
indebted for their daily guidance and cooperation through the Northern Dohoku Imaging
Research Group.
The technologists from the Souya region
and northern Rumoi region are registeredmembers of the Hokkaido Association of Radiological Technologists Wakkanai Branch,and there are 24 members in total (including
retired technologists), which is a smaller number of technologists than that of a slightly larger hospital. I am indebted to Hajime Ohno,
the vice chair of the Hokkaido Association ofRadiological Technologists and the directorsof the Hokkaido Association of RadiologicalTechnologists and everyone else who provided their cooperation.
The region that makes up the branch has
an area of approximately 5,000 km2, which
is about the same size as Chiba prefecture.
The population in this region is small, and intowns and villages other than Wakkanai andEsashi-cho, there is probably only one technologist employed who, almost every day, isprobably taken up with waiting on standby.
The distance between hospitals means thatapart from general meetings we are usuallyunable to see each other; however, we work
hard every day and can take pride in our roleof protecting the region in the far north ofJapan. The elderly residents living in increasingly depopulated regions require even better
healthcare. Under the Wakkanai City Hospitalbranch chief Yasuyuki Hayakawa, who is incharge of the Wakkanai Association of Radiological Technologists, we clinical radiological
technologists of the Wakkanai Association ofRadiological Technologists will further improve our skills and, with determination, willprotect the residents living in the region, andcontinue to contribute to the regionʼs healthcare.

Acknowledgments
I would like to express my heartfelt gratitude to Yasuyuki Hayakawa, Chairman of the
Wakkanai Association of Radiological Technologists, Director Naomi Konta, Director Kenji
Tsuda, technologists at this hospital Yoshito
Takaya, Seiya Hayakawa, and all the membersof the Wakkanai Association of RadiologicalTechnologists, who provided their cooperation during the drafting of this paper.

Special Feature ◆ 51

Japan Association of Radiological Technologists Symposium 6（Committee on Safety Controls for Medical Radiation Exposure）

Understanding Diagnostic Reference Levels（DRLs）
Chair: Rikichi Fujiwara（Chair of the Committee on Safety Controls for Medical Radiation Exposure/Yokote Municipal Hospital）

KeynotelectureIntroduction of Diagnostic Reference Levels
to Japan
Makoto Hosono （Institute of Advanced Clinical Medicine, Kindai University）

1. Introduction
In Japan, diagnostic reference levels (DRL)
were initially established and published as the
Diagnostic Reference Levels on June 7, 2015
(DRLs 2015). There are 11 groups associatedwith medical radiation, namely the Japan Association on Radiological Protection in Medicine, the Japan Society of Medical Physics, theJapan Radiological Society, the Japan Societyof Nuclear Medicine, the Japan Society of Nuclear Medicine Technology, the Japan Society
for Oral and Maxillofacial Radiology, the Japa-

nese Society of Pediatric Radiology, the Japan
Association of Radiological Technologists, theJapanese Radiation Research Society, the Japanese Society of Radiological Technology, andthe Japan Network for Research and Information on Medical Exposure (J-RIME) (in random
order). These groups, with the cooperation of
the Japan Medical Imaging and Radiological
Systems Industries Association and the National Institute of Radiological Sciences, built an
all-Japan system, and DRLs were created on
the basis of a survey of practices in Japan forcomputed tomography (CT), general radiography, mammography, intraoral radiographic
imaging, IVR, and nuclear medicine. These
DRLs have been published with the approvalof each of the participating bodies.

2. What are diagnostic reference levels（DRLs）?
To put it simply, DRLs are the criteria medical organizations refer to in order to determine if a higher-than-necessary dose of radiation is being used for diagnoses in the medical field. According to international guidelines,

52 ◆ Journal of JART English edition 2017

including various recommendations from theInternational Commission on RadiologicalProtection (ICRP) and the international basic
safety standards set by the International Atomic Energy Agency (IAEA), DRL is an optimized
tool for protection against medical radiationin the field of diagnostics. DRL is closely tied
to the quality assurance of the equipment andmethods, as well as training and education of
the operators. These factors are considered toplay an important role in optimization. The
status of DRL overseas includes establishmentof a medical radiation protection frameworkin Europe by the European Union (EU) Council Directive 97/43/Euratom (June 1997). Within that established framework of DRL, association with the diagnostic field is required of EU
countries; therefore, based on this direction,
many countries have incorporated DRLs. In
the United States (US), the DRL presented by
the American College of Radiology (ACR),
American Association of Physicists in Medicine(AAPM), and National Council on Radiation
Protection and Measurements (NCRP) havebecome a practical standard. Note that DRL isnormally determined using the absorbed dosein the air and/or the standard phantom absorbed dose, which can be easily measured.

3. Establishing and publishing the diagnostic reference levels（DRLs 2015）
Previously in Japan a survey was conductedon the doses autonomously used for diagnosis
by J-RIME affiliated bodies, as well as various
academic institutions, organizations, and researchers. A standard diagnostic dose was advocated; however, a large number of affiliatedpersonnel were not fully cooperative with theimplementation of this standard. Therefore,
no standard DRL existed across the entire nation and it was difficult to claim that the DRL
was being implemented in medical practice inJapan.
Subsequently, in March 2010, J-RIME wasestablished as an organization to share andlink research data on medical exposure compiled by the affiliated bodies. In August 2014,as a part of these activities, a chairperson fromeach affiliated body was dispatched to forma DRL working group; thus, steps were taken
to set the DRL. The affiliated bodies jointly set
up a single platform and after investigating
the definition of a dose using the DRL anddetailed research methodologies, the working
group implemented, organized, and analyzed
the results of a large-scale, nationwide survey,
while driving discussion among the members
and referencing comments from both Japanese and international specialists. The dose
data for setting the DRL includes newly surveyed data, as well as, data from closely scrutinized existing survey results (Fig.1).
The actual DRL is posted on the J-RIME
website (http://www.radher.jp/J-RIME/) as,“Diagnostic Reference Levels Based on Latest
Surveys in Japan−Japan DRLs 2015.” Pleasereference this data.
Furthermore, Japanʼs DRL have been introduced via the websites of international institutions, such as IAEA, ISR, IOMP, and others.
Only the main points are presented for each
modality. CT targeted volume CT dose index(CTDI vol ) and dose length product (DLP)
were based on the results of two surveys on
adults. One survey targeted 712 organizations
with medical training of specialists, while theother targeted 307 facilities through a questionnaire that was included in the journal of
the Japan Association of Radiological Technologists. Subsequently, the involved professors
created the DRLs by combining the results ofthese two surveys. In addition, forward thinking was incorporated into the developmentof the DRL for dynamic liver CT scans. With anormal DRL, the dose is often based on one
image or scan. However, with dynamic liver
CT scans, a DLP of 1800 mGy/cm is the total
exposure for the entire test. For example, fora four phase equivalent protocol, each phase
Special Feature ◆ 53

Japan Network for Research and Information on
Medical Exposures（J-RIME）
・ Aim of J-RIME activities: Organized and share research data on

the actual situation of medical exposure and medical radiation
protection and contribute to the development of medical radiation exposure research, both in Japan and overseas.
・ Established in March 2010
・ Office: Medical Exposure Research Project, National Institute ofRadiological Sciences
・ 12 Organization members:− Japan Association of Radiological Technologists− Japanese Society of Radiological Technology, others
Fig.1

would equate to 450 mGy/cm. However, theDLP-based controls are for the entire test, so
the DRL can be operated for each phase irrespective of which phase protocol is being
tested, even if the target resolution differs.
With general radiography, the incidence
surface dose was set as the dose index and
the DRL was set on the basis of the results of
the latest nationwide survey (Questionnaire
Results Summary from the Survey Study ofPatient Doses during X-ray Diagnosis (2011)
presented in Asada et al . (Focusing on Factors
Relating to Imaging Conditions ─ Japanese
Journal of Radiological Technology 2012; 68(9): 1261-1268).
With mammography, the mean glandular
dose was set as the dose index and was basedon the survey results of 4816 radiographic
equipment systems for breast scans, certified
as A or B under the facility imaging certification conducted by the NPO Japan Central
Organization on Quality Assurance of Breast
Cancer Screening. A point to note include thatin other modalities the DRL is set at the 75th
percentile, but the DRL for mammography is
set at the 95th due to strict accuracy controls
already in place.
With intraoral radiographic imaging, the54 ◆ Journal of JART English edition 2017

patientʼs incident dose is set as the dose index. The DRL is based on the results of afield survey targeting 29 university dentistry
departments and dental university hospitals
conducted by the Japan Society for Oral andMaxillofacial Radiology.
For IVR, the standard point dose rate is
set as the dose index and is based on a fieldsurvey conducted at facilities with registered
technologists certified by the Japan Professional Accreditation Board of RadiologicalTechnologists for Angiography and Intervention. Data from the surveys obtained in 2008
and 2013 showed that the 2013 survey reported a lower dose than the 2008 survey.
With nuclear medicine, the actual dose is
set as the dose index and the DRL was set
based on the results of a new survey of nationwide nuclear medicine facilities. In thissurvey the 75th percentile value was used as areference, but the DRL was set after investigations conducted by the Radiological Protection
Commission of the Japanese Society of Nuclear Medicine and was based on considerationsof the actual situation and resolution of nuclear medicine scans in Japan.

Introduction of Diagnostic Reference Levels to Japan

4. The future
Encouraging the widespread application of
the DRLs set through this study in Japan is anurgent issue. Thus, it is important to repeatedly bring up this topic in workshops and scientific meetings to promote their application,
focusing on the affiliated organizations. Fostering a culture that emphasizes quality assurance, quality control, education, and training
for application of the DRLs is absolutely vital.
In December 2015, after this lecture, explanatory documents will be published by
the J-RIME DRL working group (http://www.
radher.jp/J-RIME/index.html), so please shareand actively utilize this information.
Looking into the future, the dose index
used as the basis for DRL is based on the eas-

ily measured absorbed dose in the air and/or
the standard phantom absorbed dose. This isa valid method for standardization. However,there is currently an international movement
towards finding a method that will enable thecalculation of a dose that is closer to the actual dose required for each individual patient.

5. Summary
Setting DRLs for the first time in Japan withthe cooperation of organizations involved
with medical radiation is a monumental event.
Now, it is our duty to strive for an improvement in the quality of medical radiation in
the diagnostic field and continuous utilization
through application of the DRLs.

Special Feature ◆ 55

Arts and Sciencesmaterial

Proposal for the Unification Labeling Stickers for
Emergency Shutdown System of MRI Equipment
Toshio Tsuchihashi, Koji Matsumoto, Yoshitada Masuda, Fumio Ishimori,
Hideaki Sunamori, Isao Fujita, Toshiharu Nakai

material

Current State of the Ionization Chamber Type Survey Meter Held by Medical Facilities
in the Kyoto Area: Questionnaire Survey and Calibration
Keiji Oosawa, Motohiro Nishitani, Toshinori Yamane,
Tetsuya Ookita, Toshiaki Asano, Sousuke Kusu

note

Development and Evaluation of the Safety Grid Holder
Yoshinori Takao, Minoru Hosogai, Kenji Kishimoto, Shohei Sasaki,
Masachika Shogaki, Takao Ichida, Momoyo Horiuchi

material

Fundamental Study of Magic Angle in the Meniscus of the Knee Joint
Shinjiro Kugimiya, Shinsuke Katsuki, Hisamitsu Kawasaki,
Keiko Kaneko, Hideo Tsuji, Aya Kiyota, Yuusuke Miura

note

Volumetry of the Liver: Effect of measurement using fusion images
Chikara Noda, Toshiyuki Takahashi, Hisaya Sato,
Yasuhiro Inose, Kyoichi Kato, Yasuo Nakazawa

the original work

The Influence of Incubators on Mobile Radiography of Low Birth Weight Infants
Shinichi Awamoto, Masahiro Ooga, Shuhei Ono,
Youhei Yotsuji, Toyoyuki Kato, Yoshiyuki Umezu

Arts and Sciencesmaterial

Proposal for the Unification Labeling Stickers for
Emergency Shutdown System of MRI Equipment
Toshio Tsuchihashi1）, Koji Matsumoto2）, Yoshitada Masuda2）, Fumio Ishimori3）,
Hideaki Sunamori4）, Isao Fujita5）, Toshiharu Nakai6）1）Nippon Medical School Hospital
2）Chiba University Hospital3）Seirei Memorial Hospital4）Mito Saiseikai General Hospital5）Saitama City Hospital6）Neuroimaging and Informatics, National Center for Geriatrics and Gerontology

Key words: MRI, safety, emergency shutdown system【Summary】

A magnetic resonance imaging (MRI) scanner has several buttons for safety such as an emergency stop button oran emergency operation button. In case of an emergency, the MRI operator should be able to properly operate thesebuttons. The locations and specifications of emergency buttons vary depending on the MR scanner manufacturer.
Standardization of their designs and functions will be helpful for MR operators. However, it will be difficult to change
the hardware components immediately. Thus, we designed notations in Japanese. The labeling stickers we designed
were attached beside the emergency button to represent their functions, which made it easy for MR operators tocomprehend them at a glance.

1. Introduction
Many medical institutions were affected by
the strong tremors and tsunami generated by
the Great East Japan Earthquake (magnitude
9.0, maximum JMA seismic intensity 7, JMAdata) that occurred on March 11, 2011 at 2:46
PM. This included significant damage to theexisting medical equipment. A survey was performed to reveal the state of damage to magnetic resonance imaging (MRI) equipment because of the earthquake for application in
emergency measures during disasters as wellas prevention measures (the “MRI Device Damage Questionnaire Survey” conducted from
June 14 to August 31, 2012)1), 2).
Among the responses to this questionnaire
survey, there were seven cases of problem in
immobilizing the patient table, resulting in difficulty in evacuating the patient. There havealso been reports that the emergency button
could not be located or there was confusion as

to which emergency button should be operated. It was also noted that the criteria for operating the emergency button were unclear1).
To safely evacuate patients during an emergency such as an earthquake, it is necessary toappropriately operate the emergency shutdown system (various emergency buttons).
However, compared to other medical devices,
MRI machines have a greater number of emergency-use buttons.
Looking at the multiple computed tomography (CT) devices and RI devices installed at
the authorsʼ facility, the CT devices have an
emergency stop button and a scan stop button
while the RI devices only have an emergency
stop button.
Devices using superconducting magnets arealways provided with a quench button. Other
buttons include an emergency power-off button, an emergency imaging-stop button, andan emergency exhaust fan operation button.
These buttons differ in shape (design) and inArts and Sciences ◆ 57

stallation location depending on the manufacturer. It is desirable that the specifications be
made consistent among the various manufacturers to foster an appropriate response intimes of emergency. Nevertheless, this is not
currently the case.
Reports on the status of damage to MRI machines during a large-scale earthquake include
the survey by Kamei and Noguchi after theGreat-Hanshin Earthquake3), 4), the report on
prompt quenching during the 2001 Geiyo
earthquake5), and the 2004 Mid-Niigata Prefecture Earthquake6). These reports focus on damage such as magnet displacement and mountdamage, and do not investigate the various
buttons used during the emergencies.
A rescue during the unusual situation of sustained vigorous tremors as experienced during
the Great East Japan Earthquake would place
the MRI operators under extreme stress. This
would likely put them in a psychological statein which they would be more prone to making
different errors from ordinary circumstances
because they were distracted by factors otherthan the MRI machine itself, such as the collapse of buildings, a power outage caused byinterruption of the power supply, and the occurrence of a quench7). If there are multiple
MRI machines from different manufacturers (inthe MRI Device Damage Questionnaire Survey,
94 of the 458 respondent facilities (21%) had atleast two machines installed1), 2)) or if a newmachine has recently been installed, there is
the possibility that differences in specifications
among manufacturers could lead to confusion
among operators under pressure. Those who
do not normally specialize in MRI devices
could also be forced to operate the emergency
buttons in emergency situations.
Thus, this study reports on an investigationof the emergency buttons on MRI devices thatare to be operated during emergencies. The
primary emergency situation considered in thisreport is strong tremors due to an earthquake.

58 ◆ Journal of JART English edition 2017

2. Methods
We investigated and compared the various
emergency buttons (quench button, emergency power-off button, emergency exhaust fan
operation button, etc.) on MRI devices madeby various manufacturers. We also created proposals for unified labeling stickers to supplement the emergency buttons as an interim
measure until the specifications can be unified
among the various manufacturers.

3. Results
The emergency buttons on MRI machines
differ in specifications and installation location
depending on the manufacturer but can be categorized into the following four types.
3-1. Quench (demagnetization) button

During emergencies, such as accidents involving the sticking of a large ferromagnetic
object, this button demagnetizes the strong
magnetic field (Fig.1). Depending on the manufacturer, it is installed in the MRI room or in
the control room. It includes battery power incase it must be operated during a power outage, and the batteries are checked and replaced during periodic inspections or at regular intervals.
3-2. Emergency power-off button / emergency
imaging-stop button

These buttons are usually installed on ornear the operation console, but they differ indesign and position depending on the manufacturer (Fig.2). In addition, despite having thesame naming among manufacturers, there aredifferences in the extent to which power isshut off. Furthermore, when operated, there
are models that lock the patient table and thosethat release the patient table. These differences
are shown in Tables 1 and 2.
The machines from company A release thepatient table when the emergency power-off

material
Proposal for the Uniﬁcation Labeling Stickers for Emergency Shutdown System of MRI Equipment

Fig.1 Various kinds of quench buttons
The structure and colors of the buttons aredifferent depending on the manufacturer.

Fig.2 Emergency stop button
The location of the emergency button is different
depending on the manufacturer. The color anddesign of the buttons are similar to each other.

Table 1 Emergency power-off button
The results differ by the manufacturer. In the magnetic resonance imaging (MRI) equipment in which
the bed gets locked, it is necessary to confirm the release method.

Company A

Company B

Company C

Power shutoff status

Patient table state

All the power supplied to the MRI device is shut off. The
chiller is not shut off.

Table is unlocked. However,vertical movement is notpossible.

The main breaker on the power distribution panel is tripped.
The power to the entire MRI system is shut off.
Power is not cut off to the compressor of the coolingsystem, the oxygen sensor, or the quench button.
All the power to the MRI device is shut off. The magnet
cooling mechanism also stops.

Company D All the power except to the chiller is shut off.
Company E

Patient table is locked.

Patient table is unlocked.
Patient table is unlocked.

Supply of the gradient magnetic field pulse to the gradientmagnetic field coil is shut off. Supply of the radiofrequency(RF) pulse to the transmitting RF coil is shut off.

Patient table is locked.

Power supply to the patient table is shut off.

Table 2 Emergency imaging-stop button
The results differed depending on the manufacturer. In the magnetic resonance imaging (MRI)
equipment in which the bed gets locked, it is necessary to confirm the release method.
Power shutoff status

Patient table statePower supply is shut off to the gradient amp system,
Company A radiofrequency (RF) amp system, and imaging chambermagnet device in the machine room cabinet.

Patient table is locked.

Company B Power is not shut off. Imaging stops.

Patient table is unlocked.

Company C Power is not shut off. Imaging stops.

Patient table is unlocked.

Company D Power is not shut off. Imaging stops.

Patient table is unlocked.

Company E

Patient table is locked. If pressedagain, it can be moved electrically.

Power is not shut off. Imaging stops.

button is used, but lock the patient table whenthe emergency imaging-stop button is used.
Conversely, those from company B lock thepatient table when the emergency power-off
button is used but release the patient table
when the emergency imaging-stop button isArts and Sciences ◆ 59

used. Both buttons released the patient table inmachines made by companies C and D. In thecase of company E, both emergency buttons
lock the patient table, but pressing the emergency imaging-stop button again releases thelock so that the table can be moved underelectric power.
The primary application for the emergency
imaging-stop button is to immediately halt imaging. However, the emergency power-off button immediately cuts off power to the entire
MRI device aside from the cooling system.
There are devices where this halts the coolingdevice without performing a forced quench.
3-3. Forced ventilation switch

This is linked to an oxygen concentration
meter (oxygen monitor) so it operates automatically during a quench. It is frequently installed in the wall of the control room.
3-4. Testing table lock release button

This button releases the lock on the patient
table that is imposed when there has been apower outage or the emergency power-off button or emergency imaging-stop button has
been operated. It differs in installation position, shape, and manner of operation depending on the manufacturer (Fig.3).

4. Proposal for unified labelingstickers for emergency buttons
Figs.4 and 5 show the proposals for the uni-

fied labeling stickers in Japanese. An example
of a sticker in actual use is shown in Fig.6,
where the sticker is attached beside a quench
button. The sticker includes precautions for using the quench button (Fig.7).

5. Discussion
During emergencies such as earthquakes,
rescuing the patient is the initial primary concern. The emergency response for rescuing the

60 ◆ Journal of JART English edition 2017

patient during an emergency requires appropriately operating the various emergency buttons in the manner described in the operating
instructions or documentation for the device tosafely remove the patient. However, theseemergency buttons currently do not have consistent specifications. MRI devices have many
types of emergency buttons compared to othermedical devices, and many of these buttons
are located at a certain distance. In our survey,
we found significant differences in specifications and installation locations among the
emergency buttons of MRI machines. The
quench buttons had entirely different forms.
To ensure reliable operation under stress, itwould be considered significant to standardize
the specifications and create uniformity at the
hardware level. While keeping this goal inmind, we believe that it would be useful as ashort-term measure to add consistent supplemental indications to the various emergency
buttons with inconsistent specifications.
According to the “Eleventh Survey Report on
the Status of Introduction and Status of Securing Safety for Medical Imaging Systems” (issued in March, 2014) by the Japan Medical Imaging and Radiological Systems Industries Association, the replacement period for medical
devices is at least 10 years. Looking at MRI devices that are at least 1.5 T (n=588), 18.9% of
devices have been operating for at least 11
years, and the average number of years at replacement is 11.1 years. In addition, looking at
the oldest devices at each facility (n=358),
10.3% had been installed in 1999 or earlier.
Thus, it is not uncommon for MRI devices tooperate for long periods after installation. In
addition, we expect that suddenly changing
hardware would be difficult for the various
manufacturers. Thus, we believe it would be
useful to decide on easy-to-understand Japanese text and to create rules for how it is displayed. Specifically, we investigated the creation of unified rules for use in Japan for thevarious emergency buttons to be displayed be-material
Proposal for the Uniﬁcation Labeling Stickers for Emergency Shutdown System of MRI Equipment

Enlarged images

Company A

Company B

Fig.3 Lock release button（lever）of the bed
The location and design of the buttons are different depending on the manufacturer.

Quench Button

SystemOFF

・The entire MRI will stop
MRI magnetism
will disappear

Fig.4 The design of the unified labeling sticker ofa quench button（Draft）

ExhaustEmergency power-oﬀ
buttonForcedexhaustswitchEmergency
imaging-stop
buttonFig.5 The design of the unified labeling sticker ofan emergency power-off button and an emergency imaging-stop button（Draft）

The magnetic field will
disappear.

Quench Button

Restoring the system will require tremendous cost and time.

【Examples of use】
When a ferromagnetic body cannot be
removed by human strength alone.
When a person is immobilized between
the magnet and a ferromagnetic body,such that this may cause bodily harm.
If the building housing the MRI device
is collapsing, and there is a high probability that the machine will become
unusable.

Fig.6 An example of a quench button with the unifiedlabeling sticker.
The function of the button becomes clear with theunified labeling sticker.

Fig.7 Criteria for use of the quench button.
By displaying the function and criteria for use of the button, it
becomes useful under emergency situations.

Arts and Sciences ◆ 61

side those buttons to be easily understood byeveryone. Eventually, it will be necessary to
make proposals to the industry for this to bereflected at the hardware level.
The labeling stickers should enable anyone
who sees them to understand the result ofpressing the associated button. However, theemergency power-off buttons and emergency
imaging-stop buttons differ in the extent towhich they cut off power as well as the final
state of the patient table (locked or free). Thus,
the unified labeling stickers must also include
information unique to each device.
The emergency power-off button locks thepatient table in some devices but unlocks it inothers. The emergency imaging-stop button
only stops imaging but leaves the power supply otherwise unchanged in some devices,while it halts imaging as well as shuts down
the power supply in other devices. Furthermore, just as with the emergency power-off
button, it locks the patient table in some devices but unlocks it in others (Tables 1, 2).
Thus, emergency buttons with the same
name have different results upon use depending on the manufacturer, and so there is thepossibility of confusion during emergencies. In
particular, if the patient table becomes locked
as a result of operating one of the emergency
buttons, it becomes difficult to extract the patient if the location for the button for unlocking
the table is not known.
Since the specifications and installation locations are not consistent between manufacturers, we believe that using the unified labelingstickers to list information for each individualmachine when the emergency buttons are used
is a method to reduce confusion during emergencies.
As seen in the examples of actual use (Figs.6,
7), despite differences in shape and installation
location depending on manufacturer, the location of the quench button can be made clear
by using the unified labeling stickers. In addition, we believe that by listing examples of sit-

62 ◆ Journal of JART English edition 2017

uations where the quench button should be
used, confusion during emergencies can be
reduced.
The MRI machine disaster questionnaire survey1), 2) asked about whether the quench button was used immediately after an earthquake,but only one facility of the 332 respondents
actually used the button. The reason given was
panic caused by the strong tremors1). Conversely, the reasons for not pushing the quench
button included “lack of opportunity to consider it due to the emergency” and “lack of clear
guidelines for making the decision.” Since theunified labeling stickers that we are proposing
clarify the criteria for use, we believe that theywould be useful in making decisions during
emergencies.
We implemented the unified labeling sticker
for the quench button on a trial basis at a facility (the authorsʼ facility) at which multiple MRI
machines from different manufacturers are installed. As a result, we heard from the clinicalradiologists specializing in MRIs that they paid
attention to the quench buttons and becameaware of their installation locations. In addition, the clinical radiologists not specializing in
MRIs (rotating specialists and those who only
work the night shift) stated that since the labels
state the function of the quench button and thecriteria for its use, they would be useful during
emergencies in conjunction with regular training. However, it was also noted that the label
needed to be revised to enable fast decision-making during an emergency.
It is believed to be extremely rare for thequench button to actually be pressed by an
MRI operator. As stated earlier, the disasterquestionnaire survey only included one such
response1), 2). However, there is also a casewhen a nurse using ankle weights become
magnetically stuck to the MRI machine and unable to move, after which the quench button
was pressed on the operatorʼs judgment8).
Thus, there are situations in which the quench
button must be used based on the MRI opera-

material
Proposal for the Unification Labeling Stickers for Emergency Shutdown System of MRI Equipment

torʼs judgment during an emergency; therefore,
the unified labeling seals that we propose areuseful in clearly listing the criteria for use.
Finally, the various emergency buttons usedduring emergencies currently differ greatly infunction and installation location among thevarious manufacturers. At each facility, it isnecessary to confirm the position of each
emergency button on the machines currently
in use and to reconfirm the resulting state of
the machine when the buttons are operated.
To this end, it is important to conduct thorough training for the MRI operators and implement full measures for occupational safety.

6. Conclusions
This study confirmed the specifications forthe emergency buttons used during emergencies on the MRI devices produced by the five
major manufacturers and investigated an interim plan of action until the specifications can be
unified among these manufacturers.
The emergency response for patient evacuation requires appropriately operating the various emergency buttons. The specifications andform factors of these emergency buttons differ
by manufacturer, and hence, their appropriate
operation will require unifying the specifications and installation locations.
We expect that considerable time will be required before there is consistency in the industrial specifications. Thus, this must be preceded by efforts to tackle the current situation.
Our report proposes unified labeling stickers,
but we hope the efforts to tackle the current
situation will continue to progress.

References
1） Toshiharu Nakai : Health and Labour Sciences Research Grant, Local Medical Foundation Development/Promotion Research Program “ Formulationof anti-disaster guidelines to minimize damage andprevent secondary disaster effects in MRI devices
caused by large earthquakes.” 2012 Sokatsu Buntan
Kenkyusho. 2013. 3．
2） Toshiharu Nakai, Sachiko Yamaguchi, Toshio Tsuchihashi, et al.: Report on the damage situation of 602
MRI devices after the Great East Japan Earthquake.
Japanese Journal of Magnetic Resonance in Medicine, 33 (2), 92-119, 2013．
3） Hirotake Kamei: Results of surveying the damage situation of MRI devices after the Great-Hanshin Earthquake. Japanese Journal of Magnetic Resonance in
Medicine, 15, S141-142, 1995．
4） Cryogenics and Superconductivity Society of Japan:
1995 Damage Investigation Special Committee, Damage survey report for cryogenic and superconductive
devices due to the Great-Hanshin Earthquake. Cryogenics and Superconductivity Society of Japan, 1996.
5） Hiroaki Takiguchi: Academic Forum. Risk Manage ment during MRI Testing ─ Experiences of Quenching due to Earthquake. Journal of the Labor Welfare
Corp. Radiological Technologists, 22, 69-73, 2003．
6） Eiji Sato: Special project for preventing/reducing damage due to an earthquake directly below the capital ②: Evaluation of the seismic resistance of city facilities
and study on maintaining functionality. 2007 Report,
9-21, 2008．
7） Toshiharu Nakai: Health and Labour Sciences Research Grant, Local Medical Foundation Development/Promotion Research Program. “ Formulationof anti-disaster guidelines to minimize damage andprevent secondary disaster effects in MRI devices
caused by large earthquakes.” 2013 Sokatsu Buntan
Kenkyusho. 2014. 3．
8） Toshio Tsuchihashi: Latest information on the safe
management of MRI testing. Eizo Joho Medical, 44(14), 78-85, 2013．

Arts and Sciences ◆ 63

Arts and Sciencesmaterial

Current State of the Ionization Chamber Type
Survey Meter Held by Medical Facilities in the
Kyoto Area: Questionnaire Survey and Calibration
Keiji Oosawa1）, Motohiro Nishitani2）, Toshinori Yamane3）, Tetsuya Ookita4）,
Toshiaki Asano4）, Sousuke Kusu4）1）Saiseikai Kyoto Hospital2）Kyoto College of Medical Science3）Nantan General Hospital4）Kyoto College of Medical Science (student)

Key words: Survey meter, calibration, medical facility【Summary】

In the medical field, radiological technologists use many types of survey meters for management of radiation
facilities. However, each facility has different management practices. We performed a questionnaire survey to evaluate
the present conditions of the radiation meters used in medical facilities in the Kyoto area. The results indicatedthat many facilities did not perform periodic calibration of the survey meters. We calibrated 53 units of ionizationchamber type survey meters at the energy levels in the diagnostic areas. The average calibration was 0.996, and thestandard deviation was 0.124. In addition, many ionization chamber type survey meters were old. Verification of theperformance of survey meters is required during regular calibration. Kyoto Association of Radiological Technologists
decided on implementing annual calibration of ionization chamber type survey meters.

1. Present conditions of survey
meters in medical facilities
1-1. Introduction

Since the Fukushima Daiichi Nuclear Power
Station accident caused by the Great East Japan
Earthquake in March 2011, an increasing number of laypersons are purchasing radiation meters for personal use. It is unclear whether
these devices are properly managed and used
to measure radiation accurately. In addition,
each medical facility has different management
practices for survey meters, including calibration, and the actual condition of their use isunknown. The use of an unknown calibration
constant when measuring scattered dose andleakage dose results in inaccurate measurements. The “Act on Prevention of Radiation
Hazards due to Radioisotopes, etc.” and “Medical Care Act” recommend annual calibration ofsurvey meters that are used in medical facilities
to measure leakage doses, etc1), 2).

64 ◆ Journal of JART English edition 2017

To understand the present condition of survey meters used in medical facilities, we conducted a questionnaire survey in facilities within the Kyoto Prefecture. Based on the results ofanalyses, practical measures were proposed.
1-2. Questionnaire method

We mailed the questionnaire to the directorsof all facilities who employed The Kyoto Association of Radiological Technologists member
affiliates (132 facilities) and requested returnmail of the anonymous response.
Responses were received from 75 facilities,
with a recovery rate of 56.8%. Table 1 shows
the questions and responses associated withthe study.
1-3. Questionnaire results

The questionnaire results indicated the presence of 73 units of survey meters at 33 facilities; of these, about half (37 units) were ionization chamber-type survey meters. Fig.1 showsmaterial
Current State of the Ionization Chamber Type Survey Meter Held by Medical Facilities in the Kyoto Area: Questionnaire Survey and Calibration

Table 1 Questions and answers of the questionnaire related to this study
Answer and questionnaire（I have excerpted those used in the contents of this paper.）Q1 Do you own a survey meter?
yes
33facilities
no39facilities
3facilities
Rent from suppliers or related hospital
Q2 Answered "yes" Please tell me the number and types
Ionization chamber type 1unit 25facilities
2units ４facilities 4units 1facility
GM tube type 1unit １３facilities 2units ４facilities 3units １facility
Scintillation type 1unit ８facilities 2units １facility
Proportional counter tube type2facilities
Q3 Frequency of use How much is?
Ionization chamber type
GM tube type
Scintillation type
Proportional counter tube type
Ｑ4 Who do you use?
Radiological technologists
Other(Appendix）

33facilities
2facilities

Ｑ5 Who will manage?
Radiological technologists
Other

33facilities
4facilities

Ｑ6 Interval of calibration How much?
Every year
7facilities
Every two to three years
11facilities
1）
Irregular
11facilities
Do not have calibration
3facilities
Plan to calibrate future
4facilities
1）1facility plan to change to be calibrated every year under the guidance from the Insurance office.

Scintillation
14%

ＧＭ
33%

proportionalcounter3%

Have notbeen
calibration
8%

Ionizationchamber
50%

Plan tocalibrate
future11%
Every year
19%
Every three
years fromtwo years
31%

Irregular
31%

Fig.1 Type of survey meter that each facility
is held
Fig.1 Type of survey meter that each facility is held

Fig.2 Calibration interval of the survey meter
thateachinterval
facility
is meterheld
Fig.2 Calibrationof the surveythat each facility is held

Appendix Usage of various survey meter that each facility is held
Every day Once a week Once a month Several times a year rarely use
Ionization chamber type
GM tube type
Scintillation type
Proportional counter tube type1

the types of survey meters at surveyed facilities.
Although medical radiological technologists
were involved in management and use of survey meters at all facilities, annual calibration
was not conducted in more than half of these

3
1

9
4
3

20
5
2
1

3
2
1

facilities. As shown in Fig.2, annual calibration
was conducted in only 19% of the facilities.
Three facilities did not conduct any calibration,
due to the high cost involved.
As for the usage, some facilities responded
that they “hardly ever use” GM - and scintillaArts and Sciences ◆ 65

tion-type survey meters; however, all facilities
responded that they used the ionization chamber-type survey meters at least several times ayear. The details are shown in the Appendix.

2. Toward practical measures
To understand the performance, purchasetiming, and management status of the ionization chamber-type survey meters (hereafter referred to as “survey meters”) that were mostcommonly used at all responding facilities, andto examine whether The Kyoto Association ofRadiological Technologists and Kyoto Collegeof Medical Science could lead regular calibrations, we gathered survey data from medical
facilities in and around the Kyoto Prefecture.
2-1. To participate in “Attempt of Questionnaire
Survey and Calibration”

We aimed to determine the characteristics ofsurvey meters by manufacturing companies
and models. In December 2012, we mailed inquiries on willingness to participate in “Attemptof Questionnaire Survey and Calibration,” tothe directors of 132 facilities with which members of The Kyoto Association of RadiologicalTechnologists were affiliated and approachedmedical facilities and offices in neighboring
prefectures as well. On principle, survey meters were to be brought to our facility for no-

ROTEM
Ouyougiken, Ltd.
【Sangyo ROTEM
Kagaku Co., Ltd.】 OUYOU【Applied Engineering Inc.】
GIKEN
4%
Fuji
Electric,Ltd.
FUJIDENKI
4%
5%

FLUKE
33%

ALOKA
54%

cost testing.
2-2. Results

From the Kyoto Prefecture, 69 facilities responded including those without survey meters. Before performing calibrations, we confirmed the performance of the target survey
meters using a 226Ra check source. Results showedthat instrument readings of several survey meters was abnormal, and these were excluded
from calibrated models. Twenty-six facilities
provided 38 units that were functioning normally; additionally, we received 15 units used
regularly by nearby prefectures. The final tallyof survey meters to be calibrated was 53.
The most common manufacturer was Hitachi
Aloka Medical, Ltd. (including Aloka) at 54%,
followed by FLUKE Inc. (including Victreen,
INOVISION, and Cardinal Health) at 33%, andothers (three Fuji Electric, Ltd. two ROTEM,
Inc. Sangyo Kagaku Co., Ltd.: Sales agent of
the product , and two Ouyougiken, Ltd. Applied Engineering Inc. ) at 13% (Fig.3). On adjusting the schedule based on each facility, we
conducted measurements within a total of fourdays between late February to early April 2013.

3. Attempt of Questionnaire
Survey and Calibration
Highly precise and stable X-ray devices are
required for calibration of survey meters. X-ray
devices for calibration and measurement devices owned by Kyoto College of Medical Science had the capability to comparatively calibrate ionization chamber type survey meterswith diagnostic range of energy according to
the JIS standard. Hence, we used these devices
for comparative calibration of survey meters.
3-1. Devices in use

Fig.3 The ratio of Manufacturers）
surveymeterin provided
this instudy
Fig.3 （Thecalibrated
ratio of Manufacturers（Survey meterthat has been
this study）

66 ◆ Journal of JART English edition 2017

X-ray device: TAITAN 225S
(GE Inspection Technologies)
X-ray tube voltage, 5–225 kV (0.1
kV step); X-ray tube current, 0.1–

material
Current State of the Ionization Chamber Type Survey Meter Held by Medical Facilities in the Kyoto Area: Questionnaire Survey and Calibration

Table 2 Main models of survey meter wascalibrated（by manufacturers）

2
1.8
1.6
1.4

Ｓｖ／Ｇｙ

Manufacturer
The main models
Hitachi Aloka Medical, Ltd. ICS301.311.315.321.331
FLUKE, Inc.
450B.450P.451B.451P
Fuji Electric, Ltd.
NDR131.NHAROTEM, Inc.
RAM DA 2000
Ouyougiken, Ltd.
AE-133

1.2
1
0.8
0.6
0.4

Table 3 The measurement accuracy of the X-ray
equipment and a reference dosimeter thatwas used to this study
Voltage of X-ray tube 70kV Voltage of X-ray tube 120kV

Number ofmeasurements

1
2
3
4
5
6
7
8
9
10

First time

119.1
119.3
119.4
119.4
119.4
119.3
119.3
118.9
119.4
119.4
Average value（ｍＲ）
119.3
Standard deviation
0.1663
Coefficient of variation 0.1394%

Second timeFirst time

Second time

119.2
119.1
119.1
119.4
119.3
119.2
119.2
119.5
119.3
119.2
119.3
0.12690.1064%

169.8
170.0
169.9
170.1
170.0
169.9
170.2
170.2
170.0
169.9
170.0
0.13330.07840%

166.9
167.0
166.9
166.8
166.9
166.9
167.0
167.0
167.1
166.7
166.9
0.11350.0680%45 mA (0.1 mA step); and the stability and reproducibility of tube voltage and current, within ± 0.05%.
Dosimeter: RAMTEC 1500B (Toyo Medic)
Detector: DC300 (Wellhöfer)Ionization chamber-type survey meters to becalibrated: Hitachi Aloka Medical,
Ltd., FLUKE, Inc., ROTEM, Inc.,
Fuji Electric, Ltd., and Ouyougiken, Ltd. The major models areshown in Table 2.
Standard dosimeter used for comparative
calibration belonged to Japanese Society of Radiological Technology Diagnostic DosimeterStandardizing Center (Kinki Region Center),and was calibrated by Japan Quality Assurance
Organization (JQA).
3-2. Method to examine accuracy of standard
dose measurement

To examine the measurement accuracy when
X-ray device and standard dosimeter are combined, measurements were taken 10 times each

0.2

10

20

30

40

50

60

70

keV

Fig.4 1cm dose equivalent conversion factor
Fig.4 tables
1cm dose inequivalent
conversion
factor tables in 20keV to 60keV
20keV
to 60keVwith the following settings: tube voltage, 70 kV
and 120 kV; tube current, 40 mA; irradiation
distance, 3.25 m and 5.0 m; and irradiation
time, 5 s. Average, standard deviation and coefficient of variation (%) were obtained. Results are shown in Table 3. The measurement
distance of 3.25 m is the reference point for thedose measurement for the specification of ourcalibration site. Actual calibration of the survey
meter was performed at 5.0 m. Results showedthat reproducibility of the dose measurement
was favorable, and coefficient of variation was
stable within 0.15%.
3-3. Calibration methods
3-3-1. To obtain 1 cm dose equivalent

Calibration of the survey meter was performed according to the JIS Z 4511 “Methods ofCalibration for Exposure Meters, Air Kerma
Meters, Air Absorbed Dose Meters and Dose
Equivalent Meters”3).
The standard dose for the calibration sitewas measured by Air Kerma (Gy) at the calibration point. To convert the obtained Air Kerma to the survey meter display of 1 cm dose
equivalent (Sv), it was multiplied with the coefficient obtained from 1 cm dose equivalent
conversion coefficient (1 cm dose equivalent
for a site) shown in JIS Z 45113). Fig.4 shows
the graph of 1 cm dose equivalent conversion
coefficient at 20-60 keV obtained from JIS.
Since conversion coefficient changes rapidly atArts and Sciences ◆ 67

Shutter(roof ) reference measurement device orcalibrated measurement device
beam focus
additional ﬁlter

the centerof the beam(side wall)(side wall)(back wall)the central axis of
X-ray beam

(roof )

X-ray tube
(ﬂoor): distance between the source and the measurement device: dimension of the detection area in the measurement device: distance between the measurement device and the back wall

(ﬂoor): distance between the central axis of the beam and the ﬂoor
: distance between the central axis and the side wall (including the roof): beam divergence angle

Fig.5 Geometry of JIS and placement of theexperiment（reprinted from JIS Z 4511: 2005）
Fig.5 Geometry of JIS and placement of the experiment (reprinted from JISz4511:2005)

the energy in the diagnostic range, X-ray energy used for irradiation must be measured accurately. Therefore, we used high purity (99.99%)
aluminum to obtain half-value layer and in
turn, equivalent energy. The value of absorption coefficient to obtain the equivalent energy
was as reported by Seltzer and Hubbell 4).
Results showed that X-ray used for calibration had equivalent energy of 33.2 keV andconversion coefficient of 1.21 at the tube voltage of 70 kV, and equivalent energy of 42 keV
and conversion coefficient of 1.50 at the tube
voltage of 120 kV.
3-3-2. Calibration arrangements

The calibration site was arranged according
to the geometry of JIS Z 4511 “A case of X-ray
Irradiation”3) shown in Fig.5. Calibration was
performed with the substitution method at thereference point (5.0 m), where the reference
dose was measured at the calibration site. Considering the time constant of the survey meter,
measured values were obtained 40 s after starting the irradiation.

Fig.6 X-ray equipment used for calibration

Fig.7 The placement of the survey meter at thetime of calibrationfrom the side wall could be ignored. Scattered
X-ray from the back wall could also be ignored
since it was 4.65 m away from the back wall.
Though JIS uses a circular irradiation field, in
this study, we used a 5 × 5 cm focus at 1 mfrom the X-ray tube focus, which forms a 25 ×
25 cm square at the irradiation position of 5.0
m. The photograph of the X-ray device used in
the study is shown in Fig.6, while Fig.7 shows
the arrangement of the survey meter.
3-4. Calibration results

3-3-3. Calibration methods

With the present arrangement, the left wall
direction was 1.3 m, which was shorter than in
JIS; however, since the beam angle θ was extremely acute at 2.86 degrees, there was no
scattered X-ray from the wall, and the impact

68 ◆ Journal of JART English edition 2017

Calibration results of all 53 units survey meters at 70 kV had a mean calibration constantof 0.996, with a standard deviation of 0.124.
Fig.8 shows the calibration constants obtained
from the experiment.

material
Current State of the Ionization Chamber Type Survey Meter Held by Medical Facilities in the Kyoto Area: Questionnaire Survey and Calibration

1.5

Within five
years
13%

1.4

Unknown34%

1.3
Ｃａｌｉｂｒａｔｉｏｎ factor

1.2

ALOKA

1.1

FLUKE type‐P

1

FUJIDENKI

0.8
0.7

OUYOUGIKEN

0.6

ROTEM

0.5

Over tenyears
34%

FLUKEtype‐B

0.9

0

10

20

10 Within 5
years or
more
19%

30

Ｕｎｉｔｓ

Fig.8 Calibration factor of the survey meter
Fig.8 Calibration factor of the survey meter obtained from experiments
obtained from experiments

Fig.9 The time when the survey meter was
Fig.9 The
time when the survey
meter was purchased（
meter
that has（Surveypurchased
meterSurvey
that
has
been
been provided in this study ）provided in this study）

3-4-1. Results by manufacturers

Mean calibration constants of the survey meter (Fig.8) from each manufacturer are shown
below.
Twenty-eight units from Hitachi Aloka Medical, Ltd. showed little difference between eachmodel, and the mean calibration constant was
0.957 with a standard deviation of 0.079.
Eighteen units from FLUKE Inc. had a meancalibration constant of 1.095 with a standard
deviation of 0.13.
Devices from FLUKE Inc. can be divided into
two groups: P-type, wherein the gas is sealedin the ionization chamber and pressurized; andB-type, wherein no pressure is applied.
Eleven FLUKE Inc. P-type (pressurized ionization chamber) had a mean calibration constant of 1.147 with a standard deviation of
0.105.
Seven FLUKE Inc. B-type (normal ionizationchamber) had a mean calibration constant of
1.013 with a standard deviation of 0.129.
Overall, P-type survey meters tended to havea higher calibration constant.
3-4-2. Purchase timing

Of the 38 units survey meters belonging to
medical facilities in the Kyoto Prefecture
brought in for the present “attempt of calibrate”, 26 units (68%) were purchased at least
10 years ago, or their purchase timing was unknown; 5 units (13%) were purchased within

Or unknown
for more than
10 years
29%

Calibrated
within 3 years
47%

Calibrated
within 5 years
more than
3 years
19%
Calibrated
within 10
years morethan 5 years
5%

Fig.10 The time of calibrated the most recent
Fig.10 The time of calibrated the most recent（ Survey meter that has been provided in this study ）（Survey meter that has been provided inthis study）

the last 5 years (Fig.9).
3-4-3. Calibration timing

Similarly, the final calibration of 38 units belonging to medical facilities in Kyoto Prefecture was at least 10 years ago or unknown in
11 units (29%); 18 units (47%) were calibrated
within the last 3 years (Fig.10).

4. Discussion
The results from the present “Attempt ofQuestionnaire Survey and Calibration” confirmed that many survey meters were not regularly calibrated. Specific characteristics bymanufacturers and models, as well as individual differences between each model were observed.
Arts and Sciences ◆ 69

In the past, many survey meters (including
those calibrated irregularly) were calibrated
with 137Cs. Hence, caution is required when using these meters to measure leakage dose andscattered dose distribution in the diagnostic
range. For example, based on the manufacturer specifications5), the relative sensitivity of
FLUKE Inc. 451P-type does not show muchdifference in measuring 137Cs between the frontand sides of the survey meter, but for measurements in the diagnostic range (around theequivalent energy of 30 keV), the front andside surfaces show more than the two-fold difference and energy-dependence is significant.
More accurate values can be obtained byconsidering the calibration constant at the energy range that matches actual usage.
Regular confirmation of the performance isnecessary, since many in-use survey meters areold. Especially, the types wherein pressure isapplied to the ionization chamber may lose thegas over time, which could lead to decreased
sensitivity. Among survey meters that were included in the current study, some showed anormal background range but a 50% reduction
in sensitivity in actual measurement of the calibration sites was observed (excluded from thedata analyses).
Performance can be maintained by calibrating every year and confirming the change. Furthermore, each facility is required to consider
the characteristics its own survey meter anduse the calibration constant that is suitable forthe target energy, in order to maintain precision of dose measurement, which leads to appropriate measurement of environmental radiation.

5. Conclusion
Due to occupational exposure to radiation,
sufficient knowledge and skills for measure-70 ◆ Journal of JART English edition 2017

ments and use of survey devices based on thecharacteristics of dosimeters is required. Calibration of dosimeters is required for reliablemeasurement results.
Based on the results of the present study,
comparative calibration training that has beenoffered irregularly in the past would be provided as an annual event of The Kyoto Association of Radiological Technologists as of 2014,
to confirm performances of survey meters at
facilities where annual calibration by consultants is difficult due factors such as budgets,etc.

Acknowledgements
We would like to extend our sincere gratitude to personnel from facilities that participated in the questionnaire and generously provided survey meters.

References
1） October 23, 2000, Notification from the Director of theRadiology Department, Nuclear and Industrial Safety
Agency, Science and Technology Agency “Revisionon the Radiation Hazards Prevention Act due to Incorporation of Recommendations of the International
Commission on Radiological Protection (ICRP Pub.60)(Notification)”, 2000.
2） March 12, 2001, Notice of the Director-General of
Pharmaceutical and Medical Safety Bureau, Ministryof Health, Labour and Welfare to Governors of All Prefectures: Note #188, Enforcement of Ministerial Ordinance to Revise Part of the Medical Care Act, 2001.
3） Japanese Industrial Standards: JIS Z 4511 Methodsof Calibration for Exposure Meters, Air Kerma Meters,
Air Absorbed Dose Meters and Dose-Equivalent Meters, 12-16, 2005.
4） S. M. Seltzer and J. H. Hubbell Hisashi Maekoshi
eds.: Tables and Graphs of Photon Mass Attenuation
Coefficients and Mass Energy Absorption Coefficientsfor Photon Energies 1 keV to 20 MeV for Elements
Z=1 to 92 and Some Dosimetric Materials. JapaneseSociety of Radiological Technology (11), 43, 1995.
5） Victreen 451P&451P-DE-SI Operators Manual, 4.

Arts and Sciences
note

Development and Evaluation of the Safety Grid
HolderYoshinori Takao1）, Minoru Hosogai1）, Kenji Kishimoto1）, Shohei Sasaki1）,
Masachika Shogaki1）, Takao Ichida1）, Momoyo Horiuchi2）
1）Osaka City University Hospital, Department of Radiology, Radiological Technologist
2）SHEEN MAN CO., LTD. Head Office Sales GroupKey words: Safety grid holder, Anti-scatter grid, ABS, X-ray imaging, Support tool
【Summary】

X-ray imaging using an anti-scatter grid has various problems associated with it. Though devised as a support tool,
the safety grid holder may also be used to improve imaging in clinical use. The safety grid holder has a structurethat covers both the grid and the cassette so that the patient does not come into contact with the grid. The prototype
was created using a polyvinyl chloride based resin, which demonstrated excellent durability. However, an improved
version created with a strong lightweight ABS resin, resulted in improved visibility along with improved X-ray
transmittance and impact resistance.
Thus, the safety grid holder both provides support for portable imaging and is an important support tool for
obtaining images quickly and safely.

1. Introduction
The anti-scatter grid (hereinafter, referred toas the “grid”) is a device positioned in front of
the X-ray receiving surface1) that is used to obtain clear images while preventing degradationin the quality of the X-ray images due to scattered radiation. Grids that are used for generalimaging are usually made of metal, such asaluminum or lead. In general, a higher gridweight results in a higher anti-scatter capability(the grid ratio). Various issues have occurred
when using grids for emergency or hospitalward imaging. There are concerns of the grids
having extremely hard and sharp corners that
correspond to the shape of the cassette2). The
most common issue is discomfort caused bygrids made of hard metal inserted with the cassette behind the subject. Less frequently, butwith more impact on the subject, abrasions
and even lacerations can occur from skin coming into contact with sharp metal corners. In
particular, it is not easy to provide protection
from the metal that pierces vulnerable skinwhere there is decreased resistance. Further-more, it is not rare to see damage to the gridcorner as a result of the grind being dropped,or misalignment when the grid and cassette areinserted behind the patient.
These grids are tools designed to improveimage quality and are used with the assumption that the user will ensure the safety of thesubject, which requires the user to pay close
attention to the safe use of these grids in a clinical setting. By resolving various issues that occur during grid photography, we devised asafety grid holder to use as an auxiliary tool forclinical application that ensures the subjectʼs
safety during rapid imaging. Two types of resins were used to create the safety grid holders,which were then compared. Various modifications to the materials and shape were made inorder to create these improved resin-based
grid holders that have superior X-ray transmittance to previously used devices.
In this report, we present our results concerning the development, evaluation, andspecifications of the modified safety grid holders.

Arts and Sciences ◆ 71

2. Method
The specifications for the resin safety gridholders are described in the following sections:materials, structure, and performance.
2-1. Materials

Plastic was chosen as the construction material considering its high durability, the ability tomaintain a clean surface, ease in processing,and various other factors. Initially, we usedhighly durable polyvinyl chloride type resin(PVC) to create a prototype. Later, we used adurable and lightweight ABS resin (ABS) to
create an improved structure3). Additionally,
the base color was also changed from off-white

to yellow. The color change to yellow wasmade after consulting the evaluation team,which was comprised of five in-house medical
radiology technicians and coordinators fromthe manufacturer. Below, we present data thatcompare the two materials discussed in thissection.
2-2. Structure

The prototype (PVC) and the improved version (ABS) have identical structures. A structure was chosen that would cover both the cassette and the grid in order to ensure that the
subject does not come into contact with thegrid (Fig.1). In the clinic, the grid would be
attached to the inner side of the safety gridab

Fig.1 Structure of the safety grid holdera）Exterior and cross section of the safety grid holderb）Usage of the safety grid holder

Table 1 Parameters of the X-ray
transmittanceFig.2 Alignment of experiment（X-ray transmittance）

72 ◆ Journal of JART English edition 2017

note
Development and Evaluation of the Safety Grid Holder

holder using double-sided tape. A gap of 1 mm
was present both vertically and horizontally
between the grid and the cassette in order tomake it possible to quickly detach the gridfrom the cassette. Moreover, small wrinkles(emboss processing) were created on the front
surface in order to reduce the friction that occurs during positioning.
2-3. X-ray Transmittance

The arrangement during the test assumed
that the images would be taken using portabledevices (Fig.2). The subject was recreated bystacking 35 cm × 35 cm acrylic boards with athickness of 1 cm. A grid that is proportional to
the thickness of the subject is used in the clinic. Therefore, we used acrylic boards with athickness of 10 cm for a grid having a 3:1 gridratio (grid density of 40) when simulating theimaging of the chest area. We used acrylic
boards with a thickness of 15 cm for a grid
having a 6:1 grid ratio (grid density of 40) to
simulate the imaging of the abdominal area
(Table 1). The parameters used for imaging the
10-cm-thick acrylic boards were a tube voltageof 80 kV, radiographic exposure of 20 mAs,
and SID of 135 cm. For 15-cm-thick acrylic
boards, the parameters were a tube voltage of
80 kV, radiographic exposure of 50 mAs, and
SID of 135 cm. The dosage measurement was
performed using an ionization chamber dosimeter (6cc chamber, Radcal 9501; produced by
Radcal) and three measurements were performed with a 10 cm ×10 cm irradiation fieldon the grid surface. The following equation(Eqn.1) was used to calculate the X-ray transmittance using the average value of the threemeasured values as the transmitted radiation
dosage incurred by these specimens.
Equation 1

Acrylic /grid transmitted radiation dosage

2-4. Impact ResistanceIn the same manner as described for the clinical practice, a grid having a grid ratio of 6:1(grid density of 40) was adhered to the safety
grid holder using double-sided tape. This grid
was then dropped consecutively ten times
from a height of 1 m onto plastic tiles while
pointing the same corner in the downward direction.

3. Results
3-1. Materials

The weight changed from 490 g to 385 g bychanging the material from PVC to ABS. Additionally, after changing the base color from offwhite to yellow, it became easier to perform
positioning during imaging and to recognize
the tube types that are used for drainage andinfusions (Fig.3).
3-2. Structure

The structure that covers the grid and thecassette prevents misalignment of the grid andthe cassette during imaging and is capable ofprotecting the subject from coming into contact with the sharp corners while protecting thecassette and grid. This structure also prevents
the grid body from being damaged and deformed, and can also be used safely with gridsthat have damaged corners due to extended
usage (Fig.4).
3-3. X-ray Transmittance

X-ray transmittance =Acrylic /material grid transmitted radiation dosage

In this evaluation, in addition to the two
types of materials described previously, a calculation was also performed for the X-ray
transmittance of dry carbon (Carbon Cassette:
Toshiba Medical Systems Corporation), which
is widely used in X-ray imaging.

× 100%We have provided a comparison of the X-ray
transmittance for each of the materials. The
X-ray transmittance for the PVC, carbon, andABS was found to be 84.5%, 94.5%, and 96.0%,
Arts and Sciences ◆ 73

Fig.3 Effect of base color changea）Proto type（Off-white）
b）Improve type（Yellow）

ab

Fig.5 Comparison of X-ray transmittance（Voltage：80kV, Acrylic phantom：10cm）
Fig.4 Effect of the safety grid holdera）Corner of the damaged gridb）Example of use the damaged gridc）Corner of the safety grid holderd）Example of use the safety grid holder

a
c

b
d

respectively, when the acrylic thickness was 10
cm (Fig.5), and the X-ray transmittance wasfound to be 86.1%, 94.3%, and 98.2%, respectively, when the acrylic thickness was 15 cm(Fig.6). With respect to both of the acrylic
thicknesses (10 cm and 15 cm), the ABS exhibited a higher X-ray transmittance compared to
the PVC or carbon. The X-ray transmittance increased when the materials were changed.
3-4. Impact Resistance

After being dropped once, the corner of thesafety grid holder of the prototype (PVC) was

74 ◆ Journal of JART English edition 2017

Fig.6 Comparison of X-ray transmittance（Voltage：80kV, Acrylic phantom：15cm）

deformed, and the grid also bent significantly(Fig.7-a, b). After being dropped ten times,
there were no further signs of large deformations. Although the improved-type (ABS) in-note
Development and Evaluation of the Safety Grid Holder

a

b

a

b

Fig.7 Result of impact resistance test（Proto type）
a）Distorted gridb）Distorted the safety grid holder

Fig.8 Result of impact resistance test（Improved type）
a）Grids protected by the safety grid holderb）Cracked safety grid holder

curred a slight bend in the grid after being
dropped three times (Fig.8-a), there were no
noticeable changes in the shape of the safety
grid holder. After being dropped six times, acrack was found on the corner of the safety
grid holder (Fig.8-b); however, there were no
significant changes in the shape after ten drops.

4. Discussion
The structure of the safety grid holder isthought to provide improved protection andprevent misalignment between the grid andthe cassette when used to image diverse areas
and regions of the subject. In particular, withrespect to the imaging of the abdominal areaand pelvic region, it is easy for misalignment tooccur between the grid and the cassette. Now,
it will be possible to use the safety grid holder
to easily insert the grid behind the subject(Fig.9-a). Additionally, safety grid holders areproduced by vacuum molding one plastic
sheet, which provides an easy surface to clean
since there are no joints. Safety grid holders
can also be applied as grid covers when stains
are anticipated on the cassette front, such as inemergency imaging of traumatized areas (Fig.
9-b).
The improvement in the X-ray transmittanceis thought to be attributable to the decrease in
the specific weight of the material. The X-ray
absorption increases as the mass number, density, and thickness increase4). Decreases in thespecific weight, brought about by changing thematerial type, are thought to contribute to theimprovement of the X-ray transmittance andreducing the mass of the grid holder itself 5)(Table 2).
When the acrylic thickness is increased,
hardening of the radiation quality is thought tocause a small difference in the X-ray transmittance between the two thicknesses of carbon
Arts and Sciences ◆ 75

Fig.9 Examples of using the safety grid holdera）X-ray imaging on stretcherb）Emergency X-ray imaging

Table 2 Characteristics of plastic＊ Modified from “Performance list of the major plastic”, Plastic reader

compared to the ABS and PVC.
The improvement in the visibility of linen
and tube types is thought to be attributable tothe use of yellow, which is more easily recognized than white. The contrast is determinedby three factors, namely, hue, saturation, andintensity. It is possible to obtain strong contrast
with colors that are farther apart on the Munsell color scale. It became easier to observe thecontrast with tubes or linen that have a highsaturation and are achromatic by changing thebase color to yellow, which has a higher intensity and is chromatic 6). There is an improvement in recognizing contamination that occurs
during treatment and an overall impression ofcleanliness is given when either white (whichis achromatic and has a high intensity) or asimilar color is used, suggesting significant
benefits associated with using yellow, which is

76 ◆ Journal of JART English edition 2017abeasily recognized.
The grid was better protected when using
the sturdy ABS. However, it was also shownthat harder materials are susceptible to cracks.
Although reinforcing the frame using metal isone method to improve durability, it presents
new problems resulting from interference withwireless systems such as the cassette-type flat
panel detectors (FPD). Metal used in the material for the grid holder is considered counterproductive since the metal will reflect and absorb the electromagnetic waves, possibly leading to problems with transmission instability or
decreased throughput for data transfer 7).
The safety of the subject should increase as aresult of using the safety grid holder, and webelieve that it will also be easier to protect thegrid owing to this. However, caution is stillneeded when handling this grid, as damage
can result in costly expenses. Future plans focus on improving the durability of the device
and refining the factors relating to imaging.

5. Conclusion
In this report, we have provided specifications for the safety grid holder and the modifications relating to its development and evaluation thereof. The safety grid holder, which iscapable of resolving many of the issues associated with portable imaging, is an auxiliary toolthat adequately supports the grid imaging used

note
Development and Evaluation of the Safety Grid Holder

in emergency settings and hospital ward imaging, enabling quick and reliable imaging while
improving the safety of the subject.

6. Acknowledgments
We would like to express our deep gratitude
to the staff of the Osaka City University Hospital Central Radiotherapy Dept. for guidanceand encouragement that was provided for thisreport.
References
1） Japan Medical Imaging and Radiological Systems
Industries Association - QA Committee: JISZ4910:
2000.

2） Japan Organization for Emergency Radiological Technologies: A list of issues that can occur with portable
photography. Japan Organization for Emergency Radiological Technologies Home page. (http://www.jert.
jp/news/portable.html) Viewed on Nov 2015.
3） The Society of the Plastics Technology: The Guidebook to Plastics - revised 7th edition P73-79, P85-95.
Plastic edges, 1969.
4） Takehiro Nishidai: Radiological medical physics. P7885. Bunkodo, 1991.
5） The Society of the Plastics Technology: The Guidebook to Plastics - revised 7th edition
Appendix - List of performance for primary plastics.
Plastic edges, 1969.
6） Tadasu Oyama, et al.: An introduction to color theory:“kansei” and the psychology of color. P2-17, P55-63.
University of Tokyo Press, 2009.
7） Apple Japan: Factors that prevent wireless communication. Apple Japan HP. (https://support.apple.com/
ja-jp/HT201542), Confirmed on Nov 2015.

Arts and Sciences ◆ 77

Arts and Sciencesmaterial

Fundamental Study of Magic Angle in the
Meniscus of the Knee Joint
Shinjiro Kugimiya1）, Shinsuke Katsuki1）, Hisamitsu Kawasaki1）, Keiko Kaneko1）,
Hideo Tsuji1）, Aya Kiyota1）, Yuusuke Miura1）
1）Fukuoka Orthopedic Hospital Radiological Technologist

Key words: MRI, magic angle, meniscus, short-TE【Abstract】

Physicians must be cautious about the magic angle phenomenon in MRI, especially during the imaging of thetendons and ligaments. The magic angle phenomenon occurs when a high signal is produced by a tendon or ligament
at about 55 degrees relative to the static magnetic field. In addition to the tendons and ligaments, the meniscus is also
an object of the magic angle phenomenon, but a clear image is rarely produced. This study examined the magic angle
phenomenon of the meniscus. The magic angle phenomenon was detected in the meniscus. To rule out the magic
angle phenomenon, it is necessary to image the joint using a sequence with a long echo time (TE) or change theorientation of the tissue to avoid the magic angle.

Introduction
Magic angle phenomenon is a problem observed in magnetic resonance imaging (MRI) of
fibrous tissues such as the tendons and ligaments. In particular, the magic angle phenomenon is often observed during imaging of therotator cuff of the shoulder joint and the anterior cruciate ligament of the knee joint1)-3). The
meniscus of the knee joint is histologicallyclassified as fibrocartilages. T2＊-weighted sequences with short echo times (TE), protondensity weighted sequences, or T1-weighted
sequences are typically used to image the meniscus of the knee 4), 5). Therefore, it is highly
likely that the magic angle phenomenon affects the imaging of the meniscus 6). However,
the occurrence of false image findings in clinical settings is reported to be rare because it isbelieved that hyperintensity on the dorsal hornof the meniscus is caused by the degenerationor tear of the meniscus, and not by the magic
angle phenomenon7). In this study, we examined whether the magic angle phenomenon
would occur with respect to the static magnetic field at the meniscus using a phantom

78 ◆ Journal of JART English edition 2017

MRI method.

1. Magic angle phenomenon
Once the angle of a tendon or ligament
reaches the magic angle during acquisition of
an image with a short-TE MRI sequence, sometissues show high signal intensities that may
resemble images of pathological conditions
such as degeneration or bleeding1). The magic
angle is about 55°relative to the z-axis in astatic magnetic field. The equation for determining this angle is as follows 8)，9) : Bz ＝μ0μ(3cos2θ−1)/4πr 3, where Bz represents the zdirection component of a static magnetic field,
μ represents the magnetic moment of an
atomic nucleus, θ represents the angle of rotation around z-axis, and r represents the distance from the atomic nucleus. If Bz ＝ 0, thez-direction component in the magnetic field ona magnetic moment of an atomic nucleus canbe described by the following equation: 3cos2θ
−1 ＝ 0, or cosθ＝ 1/√3, or θ＝ 54.7°or 125.2°.
Fig.1 shows this angle domain for the static
magnetic field. The tendons and ligaments arecomprised of collagen fibers (protein) present

material
Fundamental Study of Magic Angle in the Meniscus of the Knee Joint

Fig.1 Area of 55 degree for the static magnetic
field.

Fig.3 The imaging position

Fig.2 A part of 55 degree for the static magnetic
field in the meniscus.
Fig.4 Direction of the static magnetic
field in the meniscus.

in such a manner that the water molecules surrounding the collagen fiber are constrained
and aligned along the direction of the fiber 10).
The magic angle phenomenon is observed
when that angle approaches the angle of θ.

2. Methods
By acquiring the images with varying TE after placing the phantom of the meniscus atabout 55°to the static magnetic field, changes
in the signal of the phantom were measured at
different TEs.
2-1. Equipment and coil

A 1.5 T Signa HDx MRI scanner, ver. 14 (GE)was used in this study. For evaluation of thephantom images, two 5-inch surface coils wereused as a dual coil.

2-2. 3D imaging parameters

The imaging parameters of the sequence
used in this study were as follows: repetition
time (TR), 4000 ms; TE, 13.8-111.2 ms; flip angle, 90°; matrix, 256 × 256; field of view (FOV),
15 cm × 15 cm; number of excitations (NEX),
2; slice thickness, 1 mm; fat suppression, none;
sensitivity correction, none; bandwidth (BW),
13.16 kHz; number of slices, 25; acquisitiontime, 264 s.
2-3. Phantom

Pig meniscus, which is similar to human meniscus 11), was enclosed in a joint capsule andused as the phantom in this study. Either of theregions could become the magic angle (about55°) once the meniscus is oriented in a similar
direction as in Fig.2. For the positioning, theArts and Sciences ◆ 79

Fig.5 a Meniscus image in short TE
sequence.

Fig.5 c ROI setting of high and low signal area.

（←）：High signal part in the meniscus.

2-4. Examination of phantom images

Fig.5 b Meniscus image in longTE
sequence.

tibial articular surface was placed at the centerof the surface coil and was fixed by securing
the surface coil with two towels (Fig.3). Afteracquiring several images for positioning, we
made fine adjustments so that the tibial articular surface aligned with the direction of thestatic magnetic field (Fig.4). This study was
performed after obtaining the approval of the
medical research ethics committee of our hospital. After the imaging, one orthopedist andsix radiologic technologists examined the joint
and confirmed that the meniscus used for thephantom was normal (without any pathological abnormalities).

80 ◆ Journal of JART English edition 2017

Using a short-TE to long-TE sequence, 3D
images of the region that included the meniscus were acquired. The images acquired forthe evaluation of the meniscus were generated
by reconstruction of the sequence from theoriginal image to compare the signal levels by
each sequence. With the fast spin echo (FSE),
the images were acquired using a sequencethat can change from a short-TE to long-TE byadjusting the TR and BW. The images were acquired at the following TE values (in ms): 13.8,
27.8, 41.7, 55.6, 69.5, 83.4, 97.3, and 111.2. Ineach TE sequence, five regions of interest(ROI) were set in the low signal value region(A) and the high signal value region (B) of themeniscus, and the mean signal value was calculated to measure the contrast ratio of B/A. In
this study, the size of the ROI was defined as 1
± 0.1 mm2 based on the results of the ROI
viewer measurement software. We examined
whether there were differences in the contrast
ratio between the shortest TE and the longest
TE. By determining the TE at which the contrast ratio is close to 1, we also examined
whether the TE value influences the results.
Figs.5a, 5b, and 5c show representative images
that were used for the evaluation.

material
Fundamental Study of Magic Angle in the Meniscus of the Knee Joint

3. Results
With the shortest TE sequence, the mean
ROI value of the low signal region in the meniscus was 361.2, while the mean ROI value ofthe high signal region in the meniscus was
923.2, and its contrast ratio was 2.56. With thelongest TE sequence, the signal value for thesame region was 193.6 to 188, and its contrast
ratio was 0.97. The contrast ratio of the low
signal value to the high signal value in the meniscus in each TE (ms; represented as TE [B/A])
was 13.8 (2.56), 27.8 (1.67), 41.7 (1.32), 55.6
(1.21), 69.5 (1.21), 83.4 (1.08), 97.3 (0.96), and111.2 (0.97).

4. Discussion
Since MRI images with short-TE imaging sequence are often used to visualize the meniscus, hyperintensity caused by the magic angle
may cause an error in a diagnosis that is basedon MRI examination alone. This study examined whether magic angle phenomenon occurred in the tissues of the meniscus by placing the meniscus at approximately 55°relative
to the static magnetic field. The results obtained suggest that a clear magic angle phenomenon was observed in the short-TE sequence images. The low signal value region of
the meniscus more than doubled in signal intensity compared with the initial signal value,
and the contrast ratio was 2.56. Conversely, thesignal/contrast ratio of the same regions using
the long-TE sequence images was 0.97, which
was close to 1. These results imply that inshort-TE imaging sequence of the meniscus tissues, signal values increased in the regions
where collagen fibers of the meniscus were
present at about 55°relative to the static magnetic field. In this study, the region where images for positioning aligned at about 55°relative to the static magnetic field almost corresponds to the region where the signal value
was increased. The arrangement of the menis-cus collagen fibers in this study was radial instructure at the surface, but was circular at theinterior and the radial fibers mixed with thecircular fibers around the circumference12).
Therefore, the region with the high signal value seemed to correspond with the circular fibers present at the interior. Evaluation of thecontrast ratio for each TE revealed that thecontrast ratio was close to 1.00 when the TE
was 83.4 ms or more; at these TE values, themagic angle phenomenon was not observed.
The TE values that rule out the magic angle
phenomenon are expected to vary dependingon the sequence. Nevertheless, TE can be considered an indicator to rule out the magic angle
phenomenon. The magic angle phenomenonshows increased signal value with short-TE at
the region that is about 55°to the static magnetic field. When the tendon and ligamentalign in a particular direction that is not close
to the magic angle, the positions of the protons
are constant, and T2 relaxation may be promoted by dipole interaction. However, when
the position reaches the magic angle, it cannot
be influenced by dipole interaction. Therefore,
extension of T2 occurs and the signal of the tissues can be obtained with a short-TE sequence.
However, T2 of the water molecules that arebound to macromolecules present in the tendon or ligament is considered as < 200 μs 13).
Consequently, TE is very less that even if extension of T2 relaxation occurs in the tendon orligament and decrement occurs before acquiring signals with long-TE, it does not significantly influence the signal strength. The regions with high signal values that are causedby the magic angle phenomenon actually showa normal signal at the tendon or the ligament,
not an abnormal signal. Thus, it may be decayed with relaxation time 14), and its contrast
cannot be detected like other tissues.

5. Conclusion
This study, which evaluated the magic angle
Arts and Sciences ◆ 81

phenomenon of the meniscus revealed that thesignal value with short-TE increased in the region at about 55°relative to the static magnetic
field and that the imaging of the meniscus was
influenced by the magic angle. In the verticalmagnetic field, it is necessary to be cautious
because the meniscus may orient in a directionthat is close to the magic angle. In the horizontal or supine magnetic field, the meniscus is
not close to the magic angle. Since imaging of
the meniscus is not angularly influenced in thehorizontal magnetic field, the meniscus can be

examined using a conventional T2＊-weighted
image with a short-TE, proton density-weighted
image, and a T1-weighted image. However,when meniscal tear occurs and dislocation ordeformation is severe, magic angle phenomenon may be specifically observed15). To avoid
the magic angle phenomenon, the patient
should be placed in a position in which the fiber direction is not close to 55°relative to thestatic magnetic field 1), or images should be acquired with long-TE imaging sequences suchas the T2＊-weighted imaging.

References

ground Physics and Clinical Relevance. Radiology,
188 (1), 23-25, 1993.
9） Karyn E Chappell et al.: Magic Angle Effects in MR
Neurography. AJNR, 25, 431-440, 2004.
10）Jiang Du et al.: Magic angle effect in magnetic resonance imaging of the Achilles tendon and enthesis.
Magnetic Resonance Imaging, 27, 557-564, 2009.
11）Takahashi M. et al.: Antenna technology in the bodyarea network [in Japanese]. Institute of Electronics,
Information and Communication Engineers article
magazine, J96-B (9), 907-915, 2013.
12）Ihara H.: Thoughtful knee [in Japanese]. Zennippon
byouin shuppankai, 42-59, 2002.
13）Araki T.: Definitive and perfect commentary of MRI [inJapanese]. Shujunsha (Tokyo, Japan), 281-325, 2008.
14）Matsuda T.: MR phenomenon; relaxation [in Japa nese]. Japanese Society of Radiological Technology,
58 (7), 895-903, 2002.
15）Hamada H. et al.: A patient with lateral meniscus
bucket handle tear that was transposed behind theanterior cruciate ligament [in Japanese]. Sports injuries, 12: 36-38, 2007．

1） Nishitani M.: MRI of the joint - tips for imaging andinterpretation [in Japanese]. Japanese Society of Radiological Technology, 62 (7), 924-937, 2006.
2） Suehiro M. et al.: Comparison between T2-weighted
MRI Gradient Echo and T2-weighted Fast Spin Echoin the case of cuff tear [in Japanese]. Orthopedics &Traumatology, 48 (3), 904-907, 1999.
3） Niitsu M.: A knee joint; Cross ligament [in Japanese].
Japanese Journal of Diagnostic Imaging, 19 (12),1405-1413, 1999.
4） Kanamori I. et al.: Practice of MR [in Japanese]. Iryokagakusha, 312-320, 2011.
5） Matsumoto M. et al.: Ideal MRI imaging technique [inJapanese]. Bunkodo (Tokyo, Japan), 138-160, 2008.
6） Kamei G. et al.: Structure and function of the meniscus [in Japanese]. MB Orthop, 26 (13), 1-8, 2013.
7） Peterfy CG et al.: Magic angle phenomenon a cause
of increased signal in the normal lateral meniscus onshort-TE MR images of the knee. AJR, 163, 149-154,
1994.
8） Erickson SJ et al.: The “Magic Angle” Effect: Back-82 ◆ Journal of JART English edition 2017

Arts and Sciences
note

Volumetry of the Liver: Effect ofmeasurement using fusion images
Chikara Noda1）, Toshiyuki Takahashi1）, Hisaya Sato1）, Yasuhiro Inose2）,
Kyoichi Kato1）, Yasuo Nakazawa1）
1）Showa University Graduate School of Health Sciences Radiological Technologist2）Showa University Hospital, Division of Radiological Technology Radiological Technologist

Key words: volumetry, liver, single-photon emission computed tomography (SPECT), computed tomography (CT),magnetic resonance imaging (MRI).
【Abstract】

Understanding liver function and volume as well as the positions of the blood vessels and organs before hepatectomy
is important for preventing liver failure after surgery. Information regarding liver volume is acquired by SPECT, CT, and
MRI, and a few studies have been published regarding the same. However, these studies are hampered by issues in
the accuracy of measurements. The assessment of liver volume using SPECT/CT has been recently reported. However,
not every hospital can perform this technique. Therefore, we analyzed MR images acquired during expiration in order
to assess the liver volume using fusion images acquired by both SPECT and MRI.
First, we used a tailor-made phantom of the liver to measure the volume-changing image parameter in each modality.
Then, we compared the images acquired using all three modalities. After obtaining the institutional review board
approval and informed patient consent, we measured the liver volumes of 48 patients (mean age, 68 ± 10 years),
using each of the modalities and compared them amongst each other. We assessed intra-observer reproducibility by
performing the measurements twice.
The mean total liver volume measurements obtained using SPECT, CT, and MRI were not significantly different (1176.3± 330.3 cm3, 1172.9 ± 341.7 cm3, and 1187.6 ± 334.9 cm3, respectively; p = 0.289). The mean residual liver volumes
measured using SPECT, SPECT-CT fusion, SPECT-MRI fusion, CT, and MR images showed significant differences (511.8± 301.0 cm3, 531.9 ± 266.7 cm3, 551.9 ± 269.8 cm3, 555.6 ± 259.0 cm3, and 558.0 ± 243.3 cm3, respectively; p < 0.05). The
residual liver volumes measured using SPECT, SPECT-CT fusion, and SPECT-MRI fusion images showed good intraobserver positive correlations (ρ = 0.88, 0.91, and 0.97, respectively).
We conclude that the measurement of liver volume using fusion images acquired by SPECT and MRI shows good
reproducibility.

Introduction
Liver cancer is the fourth leading cause ofdeath in Japan, after lung, stomach and coloncancer1). The incidences of lung, colon, andpancreatic cancer continue to increase, whereas that of liver cancer has decreased after peaking in the mid-2000s. There were about 33,000
cases of liver cancer in 20101). The main methods of liver cancer treatment are surgery, percutaneous ethanol injection therapy, and transcatheter arterial embolization. Many patientswith liver cancer experience complications
such as chronic liver disease, hepatitis, cirrhosis, and fatty liver. Treatment selection takes
into consideration liver function as well as thestage of cancer. It is important to understandliver function and volume as well as the locations of the organs and vessels before liver excision in order to prevent liver failure. Technetium-99m diethylenetriamine pentaacetic acidgalactosyl human serum albumin (99mTc-GSA)
scintigraphy and X-ray computed tomography(CT) can provide this information2)−6). At our
hospital, liver function is measured using 99mTcGSA scintigraphy prior to hepatectomy. Livervolume is measured using single-photon emission computed tomography (SPECT), which
provides an indication of reserve capacity after
hepatectomy. In many cases, liver volume isevaluated using CT and magnetic resonanceimaging (MRI)7)−11). Measurement of liver volArts and Sciences ◆ 83

ume using SPECT images provides inadequate
information about the vessels and lacks accuracy12). In comparison, CT provides excellent
accuracy of measurements. The volume of theliver, however, is not a reflection of liver function13). The evaluation of liver function fromMR images was recently attempted using gadoxetic sodium (Gd-EOB-DTPA). However, it
does not become instead of SPECT yet14), 15). In
addition, liver volume measurements acquired
using CT and MRI tend to be greater than theactual liver volume16). It is necessary to evaluate the information and confirm the accuracyof liver volume measurements using each modality prior to hepatectomy. Accuracy has beena problem when SPECT and CT, CT and MRI
were used to measure liver volume16)−19). The
fusion of SPECT and CT images in order toimprove the accuracy of liver volume measurements was reported by a study. The accuracyof image fusion poses a problem because CT
images are usually obtained during inspiration,
while SPECT images are acquired during freebreathing. Recently, SPECT/CT has been used
in a study as a method to compensate for these
deficiencies20). However, not every hospital has
the facilities for SPECT/CT imaging. The purpose of this study was to evaluate liver volumes using a custom-made phantom as well as
clinical images acquired using three modalities
̶ SPECT, CT, and MRI.

Materials and methods
Experimental Setup

Each imaging modality was evaluated using acustom-made phantom. The phantom was composed of polymethyl methacrylate (PMMA) in a
500 cm3 solution of contrast agent (Fig.1).
Patients

The study included 48 patients (male, 31; female, 17) with or without an injured liver, who
underwent hepatectomy at the Showa University Hospital between March 2012 and August

84 ◆ Journal of JART English edition 2017

Fig.1 Tailor-made liver phantom.

2013. The mean (SD) age of the patients at thetime of surgery was 68±10 years (range, 35–83
years). The participants underwent SPECT, CT,
and MRI examinations within 2 weeks prior tohepatectomy. Finally, patients undergoing right(n = 34) or left (n = 14) lobe hepatectomy were
included, and those undergoing partial hepatectomy were excluded. Patient consent was
obtained after approval by the institutional review board of the hospital.
Imaging Acquisition

The studies were performed using a SPECT
system (Symbia S; Siemens Healthcare, Erlangen, Germany) with low-energy high-resolution collimators, a CT scanner (SOMATOM
Definition AS+; Siemens Healthcare, Erlangen,Germany), and a similar 3.0 Tesla MRI system(MAGNETOM Trio A Tim; Siemens Healthcare,
Erlangen, Germany) with a body-matrix coil aswell as a spine-matrix coil consisting of 12 coilelements. In the phantom study, the parameters for SPECT image acquisition included thefollowing: each set of projection data was ob/step, 20 s/step),
tained in 64 projections (5.6°
and the energy window was 20% width at photo-peak; for each image, the acquisition time
was assumed to be constant, and the voxel size
was changed (matrix, 64×256) as shown in Table 1. The reconstruction parameters used after
data collection were as follows: reconstruction
method, filtered back projection; filter, Butterworth; cutoff, 0.15 cycles per pixel; attenuationnote
Volumetry of the Liver: Eﬀect of measurement using fusion images

correction, none; scatter correction, none. For
volumetric imaging with CT, the acquisition
parameters were as follows: tube voltage, 120kV; tube current, 200 mA; collimation, 0.6×64
mm; pitch factor, 1.0; and rotation time, 0.5 s.
The field of view (FOV) and slice thickness
values for each image are shown in Table 2.
For MRI volumetric imaging, we used the Volumetric Interpolated Breath-hold Examination(VIBE) with 3D-GRE-T1WI sequence. The parameters included the following: repetitiontime, 3.8 ms; echo time, 1.5 ms; flip angle, 10°;matrix size, 512×512; bandwidth, 444 Hz/pixel. The FOV and slice thickness values for each
image are shown in Table 3. For image acquisition of the clinical cases, SPECT was performed with a voxel size of 9.6 mm, with freebreathing during scanning. The spatial resolution for CT was 0.68 mm×0.68 mm×0.75 mm,
and the images were acquired while holding
inspiration. The spatial resolution for MRI was
1.46 mm×1.09 mm×3.5 mm, and the images
were acquired while holding expiration. The
patients were administrated total bolus intravenous injections of 185 MBq 99mTc-GSA at scintigraphy, 600 mg/kg iodinated contrast medium at CT, and 0.10 mmol/kg Gd-EOB-DTPA at
MRI.
Image Analysis

In the phantom study, the phantom volumes
measured using each modality were compared.

Table 1 Volume of tailor-made liver phantom with
Table 1 VolumeSPECT.
of tailor‐made liver phantom with SPECT.
0.8
299.9

0.9
460.2

1
481.7

Voxel size (mm)233.9553.1 548.6 548.7

4.8
548.3

6.6
561.3

9.6
673.0
(cm3)

Table 2 Volume of tailor-made liver phantom withCT.
Table 2 Volumeof tailor‐made liver phantom with CT.
Pixel size (mm)
0.6
0.7
0.8
0.9
1.0

1
499.4
505.8
511.6
516.5
523.1

Slice thickness (mm)
2
3
4
533.1
562.6
594.3
538.9
567.6
599.0
543.3
571.7
602.9
547.3
575.2
606.4
552.6
579.2
609.7

5
626.5
630.5
634.3
637.8
641.2
(cm3)

In the clinical cases, the liver volumes were
measured using each modality and evaluated;both whole and partial liver volumes were
measured. The SPECT images were acquired
20 min after 99mTc-GSA scintigraphy, CT images
during the portal phase, and MR images during
the hepatobiliary phase of Gd-EOB-DTPA imaging. The volumes were measured using thestandard semi-automatic extraction function of
the 3D application AZE Place Raijin, version
3.1 (AZE, Ltd Tokyo, Japan). In the horizontal
view, a part of the solution was extracted byenclosing the border of the solution resembling liver tissue in the direction of the bodyaxis, creating the mask shown in Fig.2, using
the radial basis function (RBF) interpolation
function. In the SPECT images, the cutoff valueof the count was set using the threshold valuechange function to remove the backgroundcount. The cutoff value was assumed to be
35% of the maximum count value21). With CT
and MRI, the liver volumes were measured using the semi-automatic extractor function, after
the main blood vessels (portal and vein), intrahepatic bile ducts, and a part of the mass were
excised at the workstation. Partial liver volumes of right and left lobes were measured
separately, and the volume on the residual side
was evaluated. The base that separated theright and left lobes was assumed to be theCantlie line. Liver volumes were also measured
using the fusion images of SPECT with CT and
MRI. As shown in Fig.3, the fusion images
were manually fitted using the workstation application.
The partial liver volumes were again measured a month later using SPECT, CT, and MRI,

Table 3 Volume of tailor-made liver phantom with
MRI.
Table 3 Volumeof tailor‐made liver phantom with MRI.
Pixel size (mm)
0.6
0.7
0.8
0.9
1.0

1
502.1
506.6
511.3
516.1
519.6

Slice thickness (mm)
2
3
4
535.3
570.8
603.0
538.3
573.6
605.8
541.7
575.6
608.3
545.5
579.5
610.4
550.5
583.2
614.1

5
640.6
643.1
645.5
648.9
652.2
(cm3)

Arts and Sciences ◆ 85

Fig.2 Liver extraction using Virtual Place. Areas
within the white enclosure show masked
images.

and the intra-observer reproducibility was evaluated.
Statistical Analysis

The Friedman test was used to determine thesignificance of the differences between the
SPECT, CT, and MRI measurements. Spearmanʼs rank correlation coefficient and Passing–Bablok regression analysis22) were used toevaluate the whole liver volumes measured
using each modality, based on the best resultof the phantom study. Intra-observer reproducibility was evaluated using Spearmanʼs rankcorrelation coefficient, Bland–Altman analysis,and Passing–Bablok regression analysis. All of
the statistical analyses were performed using
MedCalc, version 13.1 (MedCalc Software, Mariakerke, Belgium).

Results
Phantom study

The liver volume parameters measured using
SPECT, CT, and MRI are shown in Tables 1, 2,
and 3. The volumes obtained using SPECT
showed a tendency to be underestimated withdecreasing voxel size, resulting in values lower
than the true value at a voxel size of 0.8 mm.
Moreover, as the voxel size increased, the volumes also increased, resulting in an approximately 10% error compared to the true value.

86 ◆ Journal of JART English edition 2017

Fig.3 Liver Fusion by Virtual Place; The images wereacquired by SPECT and MRI.

The CT and MRI measurements approached
the true values when the slice thickness wasthin and the pixel size small, and were closest
when the slice thickness and pixel size were
0.6 mm and 1 mm, respectively. The volumes
were overestimated by CT and MRI when the
pixel size and slice thickness were increased.
Clinical study

There were no significant differences in themean whole liver volumes measured using
SPECT, CT, and MRI (1176.3±330.3 cm3, 1172.9±341.7 cm3, and 1187.6±334.9 cm3, respectively; p = 0.289) (Table 4). The SPECT and MRI
measurements were positively correlated to
the CT measurements (ρ = 0.88 and 0.99), as
demonstrated by the Passing–Bablok regression plots in Fig.4. The mean residual liver volume measurements acquired using SPECT,SPECT-CT fusion, SPECT-MRI fusion, CT, and
MRI showed significant differences (511.8±
301.0 cm3, 531.9±266.7 cm3, 551.9±269.8 cm3,
555.6±259.0 cm3, and 558.0±243.3 cm3, respectively; p < 0.05; Table 4 and Fig.5).
Intra-observer reproducibility

The liver volumes (measured twice) are
shown in Table 5. The residual liver volumes
measured using SPECT, SPECT-CT fusion, and
SPECT-MRI fusion showed positive intra-observer correlations (ρ= 0.88, 0.91, and 0.97, re-note
Volumetry of the Liver: Eﬀect of measurement using fusion images

Table 4 Liver volume in clinical cases.
Table 4 Liver volume in clinical cases.
SPECT（Non-fusion）

SPECT（Fusion with CT）

SPECT（Fusion with MRI）

CT

MRI

Total

1176.3 ± 330.3 （1127.5）--

1172.9 ± 341.7 （1080.0）

1187.6 ± 334.9 （1100.0）

0.289

Right lobe

813.7 ± 246.1 （845.0）

723.8 ± 227.1 （727.0）

731.5 ± 229.8 （758.0）

698.4 ± 249.3 （701.5）

706.3 ± 231.6 （716.5）< 0.05< 0.05

Left lobe

362.6 ± 213.2 （287.0）

452.5 ± 261.8 （405.5）

444.8 ± 237.2 （381.5）

474.5 ± 218.3 （418.0）

481.3 ± 213.6 （428.5）

Resection lobe

664.5 ± 327.8 （690.0）

664.4 ± 283.1 （678.5）

624.4 ± 274.8 （687.0）

617.3 ± 257.2 （657.5）

629.7 ± 251.6 （631.5）

0.073

Residual lobe

511.8 ± 301.0 （409.0）

531.9 ± 266.7 （501.0）

551.9 ± 269.8 （502.5）

555.6 ± 259.0 （487.5）

558.0 ± 243.3 （498.5）< 0.05(cm3)

Values are represented as Mean ± SD (Median); SD: standard deviation.
*p -value *Segment

Friedman test.

Values are represented as Mean ± SD (Median); SD: standard deviation.
*Friedman test.

Fig.4 Passing-Bablok regression analysis of total liver volume.

Fig.5 Box plot of residual liver volume in clinicalcases.

spectively); the mean differences were -13.7±
124.0 cm3, -38.3±92.3 cm3, and -4.6±73.5 cm3,
respectively (see Bland–Altman and regression
plots in Fig.6).

Discussion
In the phantom study, the volumetric measurements acquired using SPECT were underes-

timated when the voxel size was 1 mm or less,with a deficiency of count for each voxel. It
was, therefore, assumed that a voxel size of 1
mm or more was necessary for volumetricmeasurement using SPECT. When the voxel
size increased, the volumes were overestimated. The resolution ability at the PMMA-solution
border changed as the voxel size increased,
and the actual solution volume measured was
greater than its true value, possibly because of
the partial volume effect23), 24). It is necessary toextend the acquisition time in order to achieve
SPECT images with quality similar to that of CT
or MR images. However, this requires deviation from a realistic examination time. Additionally, it is assumed that the spatial resolutionof SPECT is lower than that of CT and MRI.
Therefore, we concluded that the volumes
were overestimated in the clinical cases. In the
CT and MR images, the volumes were overestimated at greater pixel size and slice thickness
values. This is similar to the phenomenon observed in SPECT, where the volume varies
Arts and Sciences ◆ 87

Table5 Intra-observer reproducibility of liver volume in clinical cases.
Table 5 Intra‐observer reproducibility of liver volume in clinical cases.
ρ A1

Modality

Segment

Time 1Time 2

Mean difference(SD2)

SPECT

Right lobe

813.7 ± 246.1 （845.0）

752.3 ± 253.4 （790.5）

61.4 (108.3)

0.92 *(Non fusion)

Left lobe

362.6 ± 213.2 （287.0）

424.0 ± 246.7（359.5）-61.4 (108.3)

0.87 *

Resection lobe

664.5 ± 327.8 （690.0）

650.8 ± 304.5（688.5）

13.7 (124.0)

0.92 *

Residual lobe

511.8 ± 301.0 （409.0）

525.5 ± 281.7（452.0）-13.7 (124.0)

0.88 *

Right lobe

723.8 ± 227.1 （727.0）

684.5 ± 240.0 （725.0）

39.3 (91.9)

0.92 *
0.87 *

SPECT(Fusion with CT)

Left lobe452.5 ± 261.8 （405.5）

491.8 ± 241.2 （456.5）-39.3 (91.9)

Resection lobe

664.4 ± 283.1 （678.5）

606.1 ± 265.8 （618.0）

38.3 (92.3)

0.93 *

Residual lobe

531.9 ± 266.7 （501.0）

570.2 ± 251.8 （527.5）-38.3 (92.3)

0.91 *

SPECT

Right lobe

731.5 ± 229.8 （758.0）

700.6 ± 230.6 （705.5）

30.8 (66.8)

0.92 *(Fusion with MRI)

Left lobe

444.8 ± 237.2 （381.5）

475.6 ± 241.8 （461.0）-30.8 (66.8)

0.95 *

Resection lobe

624.4 ± 274.8 （687.0）

619.8 ± 259.2 （634.5）

4.6 (73.5)

0.95 *CT

MRI

Residual lobe

551.9 ± 269.8 （502.5）

556.5 ± 261.2 （532.5）-4.6 (73.5)

0.97 *

Right lobe

698.4 ± 249.3 （701.5）

715.5 ± 261.2 （532.5）-17.1 (59.7)

0.97 *Left lobe

474.5 ± 218.3 （418.0）

457.3 ± 218.9 （418.0）

17.1 (59.7)

0.95 *

Resection lobe

617.3 ± 257.2 （657.5）

630.9 ± 257.4 （637.5）-13.6 (60.9)

0.96 *

Residual lobe

555.6 ± 259.0 （487.5）

542.0 ± 253.5 (457.0）

13.6 (60.9)

0.96 *

Right lobe

706.3 ± 231.6 （716.5）

721.5 ± 230.4 （745.0）-15.2 (36.3)

0.98 *
0.97 *Left lobe

481.3 ± 213.6 （428.5）

466.1 ± 212.7 （426.5）

15.2 (36.3)

Resection lobe

629.7 ± 251.6 （631.5）

633.3 ± 258.0 （639.5）-3.6 (39.2)

0.98 *

Residual lobe558.0 ± 243.3 （498.5）

554.4 ± 248.8 （473.0）

3.6 (39.2)

0.98 *

Value are Mean±SD1 (Median), SD1: standard deviation, SD2: standard deviation of mean difference.

(cm3)

*

p < 0.0001.

Value are Mean±SD1 (Median), SD1: standard deviation, SD2: standard deviation of mean difference.
*p < 0.0001.
A1: Values are represented as Mean ± SD1 (Median); SD1: standard deviation; SD2: standard
deviation of mean difference.

Fig.6 Intra-observer reproducibility of residual liver volume: Bland-Altman plot (above) and Passing-Bablok
regression (below); SD = Standard deviation.

greatly with slice thickness. We believe that the
influence of the partial volume effect caused
this variation, because the resolution ability at
the PMMA-solution border decreased as the88 ◆ Journal of JART English edition 2017

voxel size increased, and the actual solution
volume was greater than its true value23), 24).
The volume variable was influenced by pixel
size and slice thickness. However, the effect ofnote
Volumetry of the Liver: Effect of measurement using fusion images

pixel size on the volume is lower than that ofslice thickness. Therefore, we concluded thatthe change in slice thickness greatly affectedliver volumetry in the clinical cases. Finally, we
believed that CT could measure liver volume
with greater accuracy than the other two modalities. However, no statistically significant
differences were not found between thewhole-liver volume measurements acquired
using SPECT, CT, and MRI in clinical cases. It is
possible that portions of the vessels and bile
duct volumes were included in the CT image
measurements. It is necessary to recognize thiserror in liver volumetry. Moreover, owing to
the influence of the partial volume effect, agreater liver volume reduction might have occurred in the clinical study compared to thephantom study.
The patients underwent examinations with
SPECT, CT, and MRI within a 2-week period.
The doubling speed of an indistinct boundary
tumor is 106.8±20.9 days25), and, therefore, we
assumed that the tumor size would not change
in 2 weeks.
Statistically significant differences were foundin the partial volume measurements between
the three modalities. The inaccuracy of the volume measurements by SPECT might have influenced results. In addition, anatomical information is scarce for accurate SPECT image
evaluation. Therefore, the accuracy of measurement was improved by using a combinationof SPECT with CT or MRI. The combination of
CT and MRI data did not demonstrate any significant differences in the residual liver volumes. The mean difference of the SPECT volumetric measurements combined with the MR
images was less than that of their combination
with the CT images. We believe that the accuracy of the fusion measurements was influenced by the differences in the breath patternduring image acquisition between CT (inspiration) and MRI (expiration). We also believethat the image locations obtained by image ac-quisition during expiration are closer to thoseobtained during free breath than to those obtained during inspiration.

Study limitations
The cutoff value used in the present study
was assumed to be 35% of the maximum countvalue at scintigraphy, based on a previous
study21). However, the reconstruction parameters used in this study might have been different from those in the previous study. The previous study performed assessments with attenuation correction, whereas, in the present
study, attenuation correction was not performed. Therefore, the hepatic volumes measured using SPECT in the present study might
have been overestimated.
Additionally, SPECT examinations of theclinical cases did not include the evaluation ofsome of the parameters (e.g., voxel size changes from 2.0 mm to 4.8 mm) because such highresolution imaging is not practical in clinicalstudies. We believe that, had the images beenobtained at a higher resolutions, the SPECTbased volumetric measurements might havebeen more accurate. Additionally, image reconstruction in this study was performed only
using filtered back projection; we have notevaluated different reconstruction methods for
SPECT since there was no need to consider
using a different method in this study.

Conclusion
The combination of SPECT and MR images
for the measurement of liver volume could improve the reproducibility of the measurements.

Acknowledgments
The authors thank the other investigators,
educators, staff, and patients involved in thisstudy for their valuable contributions.

Arts and Sciences ◆ 89

References
1） Kazuo I, Nobuyuki K: Trend forecast of cancer deathin Japan. Tokyo healthy safety research center
research annual report, 62, 275-81, 2011.
2） O k a m o t o E : P re d i c t i o n o f t h e s a f e l i m i t s o fhepatectomy by combined volumetric and functional
measurements in patients with impaired hepaticfunction. Surgery, 95, 586-592, 1984.
3） Wu J: The functional hepatic volume assessed by
99mTc-GSA hepatic scintigraphy. Annals of Nuclear
Medicine, 9, 229-235, 1955.
4） Kubota K: Measurement of liver volume and hepaticfunctional reserve as a guide to decision-making in
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5） Mitsumori A: Preoperative evaluation of hepaticfunctional reserve following hepatectomy bytechnetium-99m galactosyl human serum albumin
liver scintigraphy and computed tomography.
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6） Yamanaka J: Impact of preoperative planning using
virtual segmental volumetry on liver resection forhepatocellular carcinoma. World Journal of Surgery,31, 1249-1255, 2007.
7） Lemke AJ: Living donor right liver lobes: Preoperative
CT volumetric measurement for calculation of
intraoperative weight and volume. Radiology, 240,736-742, 2006.
8） Li JP: Clinical application of measurement of liver
volume by multi-slice spiral CT. World Chinese Journalof Digestology, 18, 1786-1791, 2010.
9） Dello SAWG: Prospective volumetric assessment of
the liver on a personal computer by nonradiologists
prior to partial hepatectomy. World Journal of Surgery,35, 386-392, 2011.
10）Tang JH: Evaluation of computer-assisted quantitative
volumetric analysis for pre-operative resectability
assessment of huge hepatocellular carcinoma. Asian
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2013.
11）Nilsson H: Gd-EOB-DTPA-enhanced MRI for theassessment of liver function and volume in livercirrhosis. British Journal of Radiology, 86, 20120653,
2013.
12）Morikatsu Y, Shinya S: To liver function forecast-asialo
hepatic scintiscanning center after the operation.
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14）Utsunomiya T: Possible utility of MRI using GdEOB-DTPA for estimating liver functional reserve. J
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15）Jumpei S: A Study of Correlation between Gd-EOBDTPA-enhanced MRI Using the 3T MRI System andTc-99m-GSA Hepatic Scintigraphy / Hepatic Function
Tests in Prehepatectomy Cases. Showa Univ J Med
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90 ◆ Journal of JART English edition 201716）Karlo C: CT- and MRI-based volumetry of resectedliver specimen: Comparison to intraoperative volume
and weight measurements and calculation of
conversion factors. European Journal of Radiology,
75, 107-111, 2010.
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American Journal of Gastroenterology, 96, 541-546,
2001.
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and functional liver volume using technetium-99m
galactosyl serum albumin scintigraphy in patients
undergoing preoperative portal vein embolization
before major hepatectomy: A preliminary study.
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19）Reiner CS: Preoperative liver volumetry: How does
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20）Nanashima A: Correlation between morphologicaland functional liver volume in each sector using
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22）Passing H, Bablok: A new biometrical procedure
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Arts and Sciences
the original work

The Influence of Incubators on Mobile Radiography of Low Birth Weight Infants
Shinichi Awamoto1）, Masahiro Ooga2）, Shuhei Ono1）, Youhei Yotsuji3）, Toyoyuki Kato1）,
Yoshiyuki Umezu1）
1）Division of Radiology, Department of Medical Technology, Kyushu University Hospital2）Department of Radiology, University of Miyazaki Hospital3）Department of Laboratory Medicine, Kumamoto Neurosurgery Hospital

Key words: Mobile X-ray imaging, incubator, low birth weight infants【Summary】

Mobile X-ray imaging of low birth weight infants is performed with the infant in an incubator. However, the image
quality is decreased by the absorption of X-rays by the incubator.
X-ray image quality when using an incubator was estimated using image quality figures (IQFs) with a contrast detailphantom in CR and flat panel detector systems. Furthermore, the air kerma was measured using a silicon dosimeter.
The tube voltage for an infant in incubator needed to be increased by 4 – 6 kV to reach an IQF equal to that whenobtaining an image without an incubator. The air kerma was increased by 4 – 9 µGy in this situation.
In conclusion, the influence of the X-ray absorption by an incubator is important to consider during mobile X-ray
imaging of low birth weight infants.

Introduction
At present, hospital neonatal intensive careunits (NICU) use incubators to warm, isolate,and monitor low birth weight (LBW) infants
who have difficulty surviving outside the natural environment of the womb1)-3). There areclosed and open types of incubators. When
X-ray imaging is performed with a closed incubator, a mobile X-ray device is used in order toobtain images with the LBW infant inside the
incubator while maintaining proper hygiene.
During imaging, an imaging plate (IP) cassetteor other type of X-ray detector needs to beplaced directly beneath the infant. However,recent closed incubators (hereafter, incubators)
have a built-in cassette tray beneath the bed,such that X-ray imaging can be performed
without having to lift up the infant. A mechanism that allows X-ray imaging to be performed
without lifting the infant reduces unnecessary
contact between the infant and the X-ray detector, helping to prevent infections.
However, compared with placing the X-ray

detector directly beneath the infant, incubatorswith cassette trays have led to concerns regarding X-ray absorption by the acrylic hood,sponge mat, plastic bed, and other parts of the
incubator. Further, the increased distance between the X-ray detector and infantʼs body may
lead to an insufficient radiation dose whencompared with imaging conditions when the
X-ray detector is placed directly beneath theinfant, potentially resulting in lower image
quality. This means that the radiation dosewould have to be increased to obtain the sameimage quality. However, this is not recommended with LBW infants because they arehighly sensitive to radiation.
Therefore, we photographed and visually
evaluated images obtained of a contrast-detail(C-D) phantom to investigate the effects on image quality.
We also used a silicon dosimeter with a water-equivalent phantom to measure air kerma
to examine the effects of different imaging
conditions.

Arts and Sciences ◆ 91

1. Methods

C-D phantom3)-4).

1-1. Visual evaluation of the C-D phantom

1-1-1. Sample preparation

A mobile X-ray device (Sirius Star Mobile
130HP, Hitachi Medical Corp.) was used to obtain the materials for visual evaluation. The
closed incubator (V-2100G HL B, Atom Medical Corp.) used in this study has a plastic X-ray
cassette tray underneath the LBW infant bed.
This tray is pulled out to insert an IP cassette,
flat panel detector (FPD), or other device(Fig.1). For this study, we reproduced imaging
conditions by removing only the cassette tray
and sponge mat. The acrylic hood was simulated using a 5-mm acrylic board.

To simulate the geometric arrangement of
the incubator, imaging was performed with an
IP cassette placed directly beneath the C-D
phantom and with it placed in a cassette tray
(Fig.2). When the cassette tray was used, an
acrylic board of the same thickness as the incubatorʼs acrylic hood was placed between the
X-ray tube and acrylic phantom. With both the
CR and FPD systems, imaging was performed
with a tube current-time product of 2.5 mAs
and tube voltage from 46 to 58 kV in 2-kV intervals. To ensure the C-D phantomʼs holes did
not warp, the distance between the focal spotof the X-ray tube and the X-ray detector was
set at 120 cm.

Fig.1 Incubators that are used in our hospital（pull-out cassette tray）

A CR system (IP: ST-VI, IP reader FCR PROFECT CS Plus, Fujifilm Medical) and FPD system (CALNEO C mini Wireless SQ system, Fujifilm Medical) were used for the X-ray detectors.
The C-D phantom (Kyoto Kagaku Co.) used
for the visual evaluations had signals (concave
signals) of diameters ranging from 0.3 to 8.0
mm in 15 steps and depths from 0.3 to 8.0 mm
in 15 steps. For the three largest diameters,
there was a single signal in the center, similar
to conventional C-D phantoms. However, fourpoint selective C-D phantoms were used forthe remaining signals, comprising a signal in
the center and in one of the corners. Two different arrangement patterns were used in the

92 ◆ Journal of JART English edition 2017

Fig.2 Experimental design for contrast detailmeasurement.
a）Direct measurementb）Measurement using a cassette tray

1-1-2. Visual evaluation method

The samples were observed on medical-use
liquid crystal displays (RadiForce RX340: EIZO).
The brightness was fixed, but the assessors
could observe the samples at any distance andfor as long as they wanted. The evaluations
were performed independently by five radiologists. Each assessor recorded the depth atwhich each signal size in the C-D phantom
could be recognized with 50% confidence. Diagrams of the mean C-D were created for eachthe original work
The Inﬂuence of Incubators on Mobile Radiography of Low Birth Weight Infants

imaging condition and then compared. Image
quality figures (IQFs) were calculated from themean C-D diagrams to compare the IQF between imaging conditions4)-5).

higher with the CR system and FPD system,
respectively, when the cassette tray was usedcompared with when it was placed directly un-

The same mobile X-ray device was used tomeasure the radiation dose with a silicon dosimeter (Unfors Xi: Toyo Medic). An R/F detector was used as the radiation detector (Fig.3).

Aperture depth [mm]1-2. Air kerma measurement

SCD: direct measurement ‒ 93 cm
Measurement using cassette tray ‒ 90 cm

Acrylic phantom: 5 mm
(used only with cassette tray)

Fig.4 Contrast detail curves of images acquired using
direct measurement with the CR system.

The distance between the X-ray tube focal
spot and X-ray detector was set at 93 cm (90cm with the cassette tray). The dosimeter wasplaced on the surface of a 7-cm thick water-equivalent phantom. A 5-mm thick acrylic
board was placed 20 cm from the dosimeter tosimulate the incubatorʼs acrylic hood. Irradiation was performed under the same imaging
conditions as for the visual evaluations (Fig.3).

2. Results
2-1. Visual evaluation of the C-D phantom
Figs.4 to 7 show the results of the visualevaluations of the C-D phantom when it wasplaced directly underneath and when using thecassette tray. Discrimination contrast of theC-D phantom decreased when the cassette tray
was used with both the CR and FPD systems.
The IQF was, on average, 13% and 12%

Fig.5 Contrast detail curves of images acquired using
the cassette tray with the CR system.

Aperture depth [mm]1-2-1. Air kerma measurement method

Aperture depth [mm]Fig.3 Air kerma measurement method

Fig.6 Contrast detail curves of images acquired using
direct measurement with the FPD system.
Arts and Sciences ◆ 93

the CR system, indicating superior image quality.
Aperture depth [mm]2-2. Air kerma measurement

The tube voltage had to be increased by 4 to
6 kV to obtain the same image quality using
the cassette tray as when it was placed directly
underneath. This increased the air kerma by
about 4 to 9 µGy (Fig.10).

Fig.7 Contrast detail curves of images acquired using
a cassette tray with the FPD system.

direct measurement
cassette tray

direct measurement
cassette tray

Fig.10 Air kerma measured using a silicon
dosimeter at different tube voltages.

Fig.8 IQF of images acquired using the CR
system.

direct measurement
cassette tray

Fig.9 IQF of images acquired using the FPD
system.

derneath, indicating poorer image quality(Figs.8, 9). The IQF was, on average, 30% lower with the FPD system compared with that of

94 ◆ Journal of JART English edition 2017

3. Discussion
LBW infants have low adaptability, so greatcare needs to be taken when imaging infants inincubators. When an incubatorʼs built-in cassette tray is not used, the infant has to be liftedup so the X-ray detector can be placed underneath. Coming into contact with an unhygienic
X-ray detector increases the risk of infection.
To reduce this risk, it is preferable to use an
incubator with a built-in cassette tray during
imaging. However, this creates problems with
X-ray absorption and increases the distance
between the X-ray detector and LBW infant.
The effects of these issues have not been clarified.
In this experiment, we found that to obtainthe same image quality when using a cassette
tray as that obtained when the X-ray detector isplaced directly underneath the infant, the tube

the original work
The Influence of Incubators on Mobile Radiography of Low Birth Weight Infants

voltage had to be raised by 4 kV, which increased the radiation dose, leading to greaterradiation exposure. Based on a proper understanding of these issues, incubators should bemade from materials that have low X-ray absorbencies.
Moreover, the FPD system exhibited superior
detectability of the C-D phantom signals thanthe CR system. The FPD system has better detective quantum efficiency (DQE) than the CR
system, which leads to better signal detectability with the same dose6). Replacing CR systems
with FPD systems could both improve image
quality and reduce radiation exposure.
As Figs.8 and 9 show, increasing the tube
voltage to deal with X-ray absorption by the
incubator body decreased IQF, i.e., improved
image quality. However, Fig.10 shows thatraising tube voltage by 4 kV increased the radiation dose by about 4 µGy. Thus, it is important to minimize radiation exposure in each
imaging session.

4. Conclusion
We used a C-D phantom to visually evaluate
the effects of an incubator on the mobile X-ray
imaging of LBW infants. The results showedthat to obtain the same image quality whenusing a cassette tray inside the incubator asthat obtained when the X-ray detector is placed
directly underneath the infant, the tube voltage

had to be increased by 4 kV, subsequently increasing the air kerma by 4 µGy.
It would be best to design incubators thatuse materials with low X-ray absorbency.
This study was presented at the 30th Japan
Conference of Radiological Technologists.

References
1） Mayumi Miwa, et al.: Maintenance and Management
for Closed Incubators: In Reference to Amendment
to Japanese Medical Care Law. Japanese Journal of
Medical Instrumentation, 82 (1), 40-48, 2012.
2） Masanori Aihara, et al.: Prevention and Control of
Nosocomial Infection caused by Methicillin-Resistant
Staphylococcus aureus in Premature Infant Ward:
Prevention Effect of “Povidone Iodine Solution” Wipeof Neonatal Skin. Japanese Association for Infectious
Diseases, 64 (6), 479-486.
3） Yuki Fukao: An infant incubator exchange criteria
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Journal of Japanese Academy of Neonatal Nursing,
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5） Emi Kinoshita, et al.: Optimization of the Chest Exposure Condition with a Contrast-Detail Phantom. Japanese Journal of Radiological Technology, 60 (7), 969974, 2004.
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Identification Utilizing Physical Image Quality Measurement in Direct- and Indirect-type of Flat Panel Detectors and Computed Radiography, 67 (11), 1415-1425,
2011.

Arts and Sciences ◆ 95

Journal of JART–English edition 2017–

March 1, 2017
Issuer: Yasuo Nakazawa
Publisher: The Japan Association of Radiological Technologists
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