Journal of— E n g l is h e d iitio
t io n —20

20

The Japan Association of Radiological Technologists

Journal of2020— 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

Regarding Publication of the English Edition
Yasuo Nakazawa, President, The Japan Association of Radiological Technologists

History

4
6

History of The Japan Association of Radiological Technologists (JART)
Featured Articles
The 35th Japan Conference of Radiological Technologists: Invited lecture

Current Status of Post-Primary Credentials: Benefits versus Disadvantages
Dr. Michael D. Ward, Ph.D., RTR, FASRT, FMoSRT Former President of ISRRTVice Dean for Student Affairs & Diversity and Professor Goldfarb School of Nursing at Barnes-Jewish College

18

Future collaboration with the European Society of Radiology and European
Federation of Radiographer Societies
Naoki Kodama

Arts and Sciences22

the original work

A Survey of Factors Influencing the Working Conditions of RadiologicalTechnologists in Japan
Hiroe Muto, Kanae Matsuura, Satoshi Nakanishi

33

the original work

Optimization of radiation exposure to the eye lens in stereotactic radiosurgery
Kohei Kawasaki, Osamu Nagano, Kyoko Aoyagi, Takahiro Kageyama

39

note

The optimal scanning method for three-dimensional T1 -weighted black-blood
turbo spin-echo MRI in the aortic arch
Kenichi Nakagawa, Masanori Kinosada, Takashi Tabuchi, Noriyoshi Morimoto, Sachi Fukushima, Takashi Ogasahara, Masayuki Kumashiro44

the original work

Evaluation of fat-suppression effects on ankle magnetic resonance imaging:
Trial of improvement of image quality by changing the posture
Hiromi Usui, Yuichi Nakai, Chikara Noda, Hisaya Sato, Kyoichi Kato51

the original work

The effect of body thickness on image quality using either a semiconductor
detector gamma camera or Anger-type gamma camera when performing a
myocardial perfusion SPECT: A Phantom study
Koji Nakaya, Yoshifumi Nouno, Ryota Kaku, Hiroe Muto, Kanae Matsuura, Ryo Higashide, Eisuke Yasuda

60

the original work

Examination of education for radiological protection/staff exposure
reduction by occupation that radiological technologists should conduct inteam medicine
Kyoichi Kato, Ikuko Sakurada, Daisuke Kittaka, Miwa Ohsawa, Kanako Numanyu, Koushi Sakiyama, Hisaya Sato, Ryu Ohishi,
Chizuko Masuda, Hiroshi Suzuki, Eiichi Geshi

71

the original work

Development of the Dual Flip-Flop Angle Type T2W-Fast Spin Echo Method
Kojiro Yamaguchi

79

Regulations and Requirements for Submissions to the Journal of the Japan
Association of Radiological Technologists
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 2020

F o r e w o r dRegarding Publication of the
English Edition
Yasuo Nakazawa (President)

Reflecting on the activities of 2019, we conveyed the policies of the Japan Association ofRadiological Technologists by dispatching committee members to events such as the Ministry of
Health, Labour and Welfareʼs “Investigative Commission for Revising Radiation Exposure Limits of
Eye Lenses,” the “Investigative Commission for Improving the Curriculum of Medical Radiologic
Technologist Schools,” and the “Investigative Commission for Promoting Task Shift/Task Sharing to
Encourage Physician Workstyle Reform.” We have communicated the activities of these committees
to our organization members through our journal. The journal of the Japan Association of RadiologicalTechnologists (JART) has a monthly circulation of around 30,000 copies, and has been well received
by our members and the public.
To give our radiological technologists from across the globe an insight into our business, I will
briefly explain the history of JART. In March 1896, we succeeded in taking the first X-ray image inJapan. In 1897, Shimadzu Corporation released an X-ray generator for educational use. In 1925,
there were approximately 1,500 X-ray technicians. In 1927, the first Shimadzu X-ray Technician
Training Institute was established, and evidence-based education was put in place. JART wasfounded in 1947 to make “radiological technologist” a national qualification. Since its establishment,
we have worked towards broad acceptance of this national qualification, in collaboration with thegovernment, the Diet, the Japanese Medical Association, and occupational military authorities.
As a result of our blood, sweat, and tears, in June 1951, we were finally able to see the promulgationof the Radiology X-ray Technicians Act, Act No.226 of 1951. Since then, we have responded to thechanging needs of the society, revising the original act to get the Radiology X-ray Technicians Act
of 1968 passed, and partially revising that to get the Radiology Technicians Act and Radiology X-ray
Technicians Act of 1983 passed, and finally getting the Radiology Technicians Act, which is in placecurrently, passed. Back then, the scope of work was limited to general X-ray testing, television X-ray
testing, angiography, X-ray computed tomography scanning, RI scanning, and radiation therapy. In
1993, the Radiology Technicians Act was further revised, and MRI scanning, ultrasonic testing, andnon-mydriatic fundus camera examination were added to the list. In 2010, image interpretation
assistance, radiation examination explanation, and consultation work were added. In April 2015,
intravenous contrast agent injection using automated contrast injectors, needle removal andhemostasis, lower digestive tract examination (anal catheter insertion and administration of contrast
medium), anal catheter insertion, and oxygen inhalation during radiation therapy were further
added as new operations that could be performed by radiological technologists.
JART will continue to respond to the needs of the medical industry, and we hope to broaden theoperational scope of radiological technologists based on our foundation in scientific evidence. We
will feature clinical, educational, and research-based achievements by radiological technologists inthe monthly issues of the JART journal, and continually work to improve the magazine. I truly hopethat this English edition will benefit radiological technicians worldwide.
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 2020

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

1998

1999

2000

2001

2003
2004

2005

2006

Staging of the 11th ISRRT World Congress at
Makuhari

2009

Renaming as public interest incorporated association JART” Presentation of the Medical Exposure
Guidelines (Reduction Targets)” for patients

Start of the Radiological Technologists Liability Insurance System

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

2013

Enactment of X-Ray Week

2014
Relocation of offices to the World Trade
Center Building in Tokyo

Establishment of the committee on Autopsy
imaging (Ai)
Revision to the national examination for radiological technologists

2015

2017

2018

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

2011

Health Policy Bureau Directorʼs notification
concerning promotion of team medicine

Consignment of work to measure personal
exposure of residents

Launch of the radiation exposure advisor
certification system

Launch of the Team Medicine Promotion
Conference, with the President of JART as its
representative2010

Signing of the Comprehensive Mutual Cooperation Agreement on Prevention of Radiation Exposure (September 21)

Revision of the Act on Radiological Technologists, Government Ordinance to Partially
Revise the Enforcement Orders, and Revisionof the Enforcement Regulations (June 25)

Start of the Medical Imaging Information Administrator certification system
Staging of a joint academic conference between Japan, South Korea, and Taiwan

Registration of transition to a public interest
incorporated association (April 1)
Event to mark the 65th anniversary of founding and transition to a public interest incorporated association (June 2)

Start of the Radiation Safety Manager certification system

Revision of the Medical Exposure Guidelines

2008

2012

2019

Event to commemorate the 120th anniversaryof the discovery of X-rays
Event to mark the 70th anniversary of founding and transition to a public interest incorporated association (June 2)
Notice from the Regional Medical Care Planning Division Director, Health Policy Bureau,
Ministry of Health, Labour and Welfare, andDirector of the Economic Affairs Division
regarding Operational Considerations for
Securing a System for Safety Management
pertaining to Medical Equipment
Notice from the Health Policy Bureau ona Safety Management System for Medicinal
Use of Radiation

Support activities following the Great East
Japan Earthquake
Staging of an extraordinary general meeting
concerning transition to a public interest incorporated association

History of JART ◆ 5

Note: This article is secondary publication, the first paper was published in the JART, vol. 67 no. 807: 44-55, 2020

The 35th Japan Conference of Radiological Technologists

Invited lecture

Current Status of Post-Primary Credentials:
Benefits versus Disadvantages
Dr. Michael D. Ward, Ph.D., RTR, FASRT, FMoSRTFormer President of ISRRTVice Dean for Student Affairs & Diversity and Professor
Goldfarb School of Nursing at Barnes-Jewish College
St. Louis, Missouri
United States of America【Abstract】

Over the decades, in the United States, the radiologic sciences have grown beyond the disciplines of radiography,
nuclear medicine and radiation therapy. There have been new developments and advances in technology and improvements in medical imaging and radiation therapeutics. We now have five “primary” categories of certification andregistration which include, radiography, nuclear medicine technology, radiation therapy, magnetic resonance imaging,and sonography.
In 1922, the American Registry of X-Ray Technicians (later the American Registry of Radiologic Technologists – ARRT)
came into being with the collaboration of its founding societies the Radiological Society of North America (RSNA), theAmerican Roentgen Ray Society and the American Society of X-Ray Technicians (later the American Society of Radiologic Technologists – ASRT). By the end of the 1930ʼs there would be more than 2,400 Registered Technologists.
In 1962, the Registry expanded its program of examination and certification by adding exams in nuclear medicine
technology and radiation therapy. By the end of the 1960ʼs, ARRT would boast a total of 56,000 certificates some
700 in nuclear medicine and nearly 300 in radiation therapy. The decade of the 1990ʼs saw a sweeping expansion of
ARRTʼs offerings. The new post-primary category was launched with certification in cardiovascular-interventional technology and mammography. New disciplines were added as technology emerged. By 2019, more than 337,000 Registered Technologists, known as “R.T.ʼs” attest to the success and strength of the American Registry of Radiologic Technologists.
The mission of the ARRT is to promote high standards of patient care by recognizing qualified individuals in medical
imaging, interventional procedures, and radiation therapy. The ARRT offers a post-primary category of certification andregistration in mammography, computed tomography, quality management, bone densitometry, cardiac-interventional
radiography, vascular-interventional radiography, cardiovascular-interventional radiography, vascular sonography andbreast sonography. The ARRT also offers certification and registration for radiologist assistants.
Besides broadening the career ladder and advancement opportunities in the medical imaging and radiation sciences,
technologists typically see increases in salaries and expansion in technical competencies and skills. Additional benefits
and advantages will be discussed during this presentation. Whenever advances take place in a profession, there could
be a downside or disadvantages that come along with those changes. One of those could be described as a “fragmentation of the profession” and “loss of identity” due to the vast array of titles as viewed by the general public.
The role of the Registered Radiologist Assistant along with the scope of practice, general competencies, and basic
salary will be discussed. As time permits, we will discuss transferability of credentials into the United States from theinternational community.

Chair Person, Nakazawa:

So just from now on, we will hold an invitedlecture. The presenter is the Former Presidentof International Society of Radiographers andRadiological Technologists whose name is Dr.
Michael Ward. But first, I will introduce his
history a little. Dr. Ward is the Vice Dean forStudent Affairs and Diversity & Professor for
Goldfarb School of Nursing at Barnes-Jewish
College in St. Louis, Missouri. At the national
level, Dr. Ward has served as Vice-President,
President and Chairman of the Board of the

6 ◆ Journal of JART English edition 2020

American Society of Radiologic Technologists.
In June of 1988, he was elevated to Fellow of
the ASRT. ASRT awarded Dr. Ward with thehighest honor, that of Life Member in June
2011. In its 90 plus year history, only 21 othermembers had been given this honor at the timeof his recognition. On September 7, 2010, Dr.
Michael D. Ward was elected the 13th Presidentof the International Society of Radiographersand Radiological Technologists (ISRRT) at themeeting held in Gold Coast, Australia. He was
first American to serve in that position, which

st‐Primary Credentials:
s Disadvantages

Ph.D., RTR, FASRT, FMoSRT

esident of ISRRT

fairs & Diversity and Professor

sing at Barnes‐Jewish College

ouis, Missouri

ates of Americacame with a four years term of office. Prior
to assuming the ISRRT Presidency, he served
seven years on the board as the Regional
Director for the Americas. Dr. Ward has servedon and chaired numerous committees andcommissions and has been very active in local,
state, national, and international radiologic
science organization. His personal motto is
to “Always Strive Towards Excellence.” Then,
talk to about current status of post-primarycredentials, benefits versus disadvantages. Dr.
Michael Ward, please start.
Dr. Michael D. Ward:

Thank you very much. First of all, I want tothank everyone for coming out this morning.
I know you have had a very busy morning
so far and to come and hear me, it brings
me great pleasure. So, thank you. I am very
happy to be here for the 35th Japan Conferenceof Radiological Technologists. And I want toCurrent
Statusthank my dear friend, Dr. Nakazawa,
Presidentof Post‐Primaryof the Japan Association of Radiological
Credentials:
Technologists, and Mr. Tanaka, the Benefits
conference
versusDisadvantages
coordinator, for this invitation.
I want to first distinguish between thetwo essential players in the radiologicalsciences in the United States ( Fig.1 ). The
ASRT, the American Society of RadiologicalTechnologists is the membership organizationthat was founded in 1920. It is the professional
membership society with its mission toadvance the medical imaging and radiation
therapy profession and to enhance the qualityof patient care. The ASRT has over 150,000
members. So, the ASRT is the professionalorganization. The ARRT is the American
Registry of Radiologic Technologists. It was
founded in 1922 and it was established as
the professional certification organization.
So, they are the ones that write the exam forpeople to become registered or certified in
the United States. And the ARRT has over
350,000 registered technologists that they
are responsible for. For the purposes of thispresentation, I will focus on the ARRT, theAmerican Registry of Radiologic Technologists,
as the credentialing organization. The ARRT
establishes the education standards forcertification.
All candidates for certification must graduate
first from an accredited educational programthat is recognized by the ARRT and since
1930, the number of certified technologists
has grown. In 1930, there were 2,400 certified
technologists; in 1962, that grew to 56,000
registered technologists; in 2012 that greweven greater to 325,000 certified technologists;
and today, the ARRT has 340,000 certified

PROFESSIONAL MEMBERSHIPSOCIETY

PROFESSIONALCERTIFICATION AGENCY[AMERICAN SOCIETY OF
RADIOLOGIC TECHNOLOGISTS– ASRT][AMERICAN REGISTRY OF
RADIOLOGIC TECHNOLOGISTS– ARRT]FOUNDED IN 1920

FOUNDED IN 1922

PURPOSE – PROFESSIONAL
MEMBERSHIP SOCIETYPURPOSE – ESTABLISH A
PROFESSIONALCERTIFICATION MECHANISMMISSION – “TO ADVANCE THE
MEDICAL IMAGING AND
RADIATION THERAPYPROFESSION AND TOENHANCE THE QUALITY OF
PATIENT CAREOVER 150,000 MEMBERSMISSION – “TO PROMOTEHIGH STANDARDS OF
PATIENT CARE BY
RECOGNIZING QUALIFIEDINDIVIDUALS IN MEDICALIMAGING AND RADIATIONTHERAPYOVER 350,000 REGISTEREDTECHNOLOGISTS

Fig.1
Featured Articles ◆ 7

ent Status
st‐Primary
entials:fits versus
dvantages

ent Status
st‐Primary
entials:fits versus
dvantages

radiographers or certified technologists thatare credentialed through the ARRT (Fig.2).
In 1922, the ARRT offered only three primarycategories for certification: radiography,
nuclear medicine and radiation therapy.
Today, there are five primary categories
in the United States: radiography, nuclear
medicine, radiation therapy, magnetic
resonance imaging, and sonography (Fig.3).
Each one of these five primary categories has
accredited programs that prepare individuals
to become one of these particular categorized
professionals. The students that graduate either
come out with certificates or they may be
graduating from a degree program. I will say
more about that later.

THE AMERICAN REGISTRY OF RADIOLOGICTECHNOLOGISTS (ARRT)ESTABLISHES EDUCATIONAL STANDARDS FOR
CERTIFICATIONCANDIDATES FOR CERTIFICATION ARE REQUIREDTO COMPLETE AN ACCREDITED EDUATIONALPROGRAM
1930 ‐ THERE WERE 2,400 ARRT CERTIFIED TECHNOLOGISTS
1962 ‐ THERE WERE 56,000 ARRT CERTIFIED TECHNOLOGISTS
2012 – THERE WERE 325,000 ARRT CERTIFIED TECHNOLOGISTS
2019 – THERE’S OVER 340,000 ARRT CERTIFIED TECHNOLOGISTSIn the 1990s, the ARRT expanded their offerings by developing post-primary certifications and, as the name implies, post-primary,the 10 certifications must be achieved after
one of the five primary certifications (Fig.4).
So, for example, in order for someone to become a mammographer, they first must be aradiographer. So, these that I have listed here,
mammography, computed tomography, magnetic resonance imaging, bone densitometry,
cardio-interventional radiography, vascular-interventional radiography, sonography, vascularsonography, breast sonography, and the physician extender or radiologist assistant. All where
it can be one of these post-primary, you musthave one of the five primary credentials first.
When I entered the radiologic technology
profession in the mid-70s, in 1970, I began asa certified radiographer. So, my background isin diagnostic radiography. There were limits on
advancement opportunities when I graduatedfrom school. There are many more now. But
if you wanted to advance in the profession,
you had to go into teaching, management, or
perhaps special procedures. The number ofyears on the job was just about the only way toadvance in salary or to expand your technicalskills. So, it was just a matter of what you knew
and how long you worked in the profession

Fig.2

IN 1922, ARRT OFFEREDCERTIFICATION

3 PRIMARY CATEGORIES OF

Current Status
RADIOGRAPHY
of Post‐Primary
NUCLEAR MEDICINE
Credentials:
RADIATION THERAPY
Benefits versus
TODAY, ARRT OFFERS
5 PRIMARY CATEGORIES OFCERTIFICATION
Disadvantages
RADIOGRAPHYNUCLEAR MEDICINERADIATION THERAPYMAGNETIC RESONANCE IMAGINGSONOGRAPHY

Fig.3

8 ◆ Journal of JART English edition 2020

BEGINNING IN THE 1990’S – ARRT BEGAN EXPANDING THEIR
OFFERINGS BY CREATING “POST‐PRIMARY” CATEGORIES OFCERTIFICATION. TODAY THERE ARE 10 POST‐PRIMARYCATEGORIES: MAMMOGRAPHY COMPUTED TOMOGRAPHY
 MAGNETIC REASONANCE IMAGING BONE DENSITOMETRY CARDIO‐INTERVENTIONAL RADIOGRAPHY
 VASCULAR‐INTERVENTIONAL RADIOGRAPHY SONOGRAPHY
 VASCULAR SONOGRAPHY
 BREAST SONOGRAGPHY
 PHYSICIAN EXTENDER – “RADIOLOGIST ASSISTANT”

Fig.4

ent Status
st‐Primary
entials:fits versus
dvantages

Current Status of Post-Primary Credentials: Benefits versus Disadvantages

in order to raise up to advanced levels. But
with post-primary certification, it has greatly
enhanced the radiologic technologistʼs career
ladders, so there is many more opportunities
for us as technologists to advance into othermodalities in the United States (Fig.5). Thereis a precise method to create new certification
specialties in the United States.
So, in order to establish new certification
categories, these have to include a practice or
job analysis that must be conducted (Fig.6),
where they review every entry-level job
responsibility, they will monitor and then lookat what tasks are involved with that particularjob. They will identify the basic knowledge
and skills required in the particular job
category, then the specific educational andclinical requirements have to be established,
and then the certification examination content,
specifications have to be developed in order
Current
Statusto meet the criteria for establishinga newof Post‐Primarycredential, and then finally, thetraining
Credentials:
material, the curriculum, the job descriptions,Benefits versus
Disadvantages
and even the performance tools
have tobe created. So, there pretty much a greatly
involved step, many steps in order to create a
new certification credential.

the primary and post-primary certificationsin the United States, and these data comefrom 2017. So, for example, in 2017 (Fig.7),
11,166 students took the certification examin radiography, with an 89.3% pass rate. For
nuclear medicine, a much smaller number ofpeople took the exam, only 379, but the passrate was 88.7%. In radiation therapy that same
year, only 807 students graduated and took
the certification exam in radiation therapy
with the pass rate of 88%. And you can see
the other post-certification pass grades. The
largest was in computed tomography were
6,423 individuals took the exam, followedby MRI were 2,649 took the exam, thenmammography with 1,595, but you will notice

SETTING THE REQUIRMENTS FOR THE CERTIFICATION AND
REGISTRATION EXAMINATION FOR PRIMARY AND POST‐PRIMARY CERTIFICATIONPRACTICE ANALYSIS (JOB ANALYSIS) IS CONDUCTEDDESCRIBES THE JOB RESPONSIBILITIES OF PEOPLE EMPLOYEDAT THE ENTRY LEVEL OF THE CATEGORYHELPS IDENTIFY THE KNOWLEDGE AND SKILLS REQUIRED TO
EFFECTIVELY CARRY OUT THE RESPONSIBILITIES OF THE
POSITION
USED TO MAKE DECISIONS REGARDING EDUCATIONAL AND
CLINICAL REQUIREMENTS FOR EACH CATEGORYUSES THE ANALYSES TO DEVELOP CONTENT SPECIFICATIONSFOR THE EXAMINATIONALSO USED TO DEVELOP TRAINING MATERIALS, EDUCATIONALCURRICULA, JOB DESCRIPTIONS AND PERFORMANCE RATING
INSTRUMENTS

Take a look at the average pass rates for
Fig.6

POST‐PRIMARY CATEGORIES MAMMOGRAPHY COMPUTED TOMOGRAPHY
 MAGNETIC REASONANCE IMAGING BONE DENSITOMETRY CARDIO‐INTERVENTIONAL RADIOGRAPHY
 VASCULAR‐INTERVENTIONAL RADIOGRAPHY SONOGRAPHY
 VASCULAR SONOGRAPHY
 BREAST SONOGRAGPHY
 PHYSICIAN EXTENDER ‐ RADIOLOGIST ASSISTANT

Current Statusof Post‐Primary
Credentials:
Benefits versus
Disadvantages

BROADEN THE CAREER LADDER AND ADVANCEMENTOPPORTUNIESNUMBER OF EXAMINEES – 2017
FIRST TIME PASS RATES IN THREE
PRIMARY CATEGORIESRADIOGRAPHY
11,166 [89.3%]

NUCLEAR MEDICINE
379 [88.7%]
RADIATION THERAPY
807 [88.0%]

NUMBER OF EXAMINEES – 2019
FIRST TIME PASS RATES IN TENPOST‐PRIMARY CATEGORIESMAMMOGRAPHY

1,595 [90.2%]

COMPUTED TOMOGRAPHY

6,423 [74.7%]

MRI2,649 [77.8%]

SONOGRAPHY

7 [83.3%]

VASCULAR SONOGRAPHY

11 [77.8%]

BONE DENSITOMETRY

358 [72.3%]

CARDIAC‐INTERVENTIONAL

192 [63.0%]

VASCULAR – INTERVENTIONAL

718 [58.4%]

BREAST SONOGRAPHY

110 [95.0%]

RADIOLOGIST ASSISTANT [2017] 21 [85.0%]

INCREASES IN SALARIES AND EXPANSION OF TECHNICALSKILLS AND COMPETENCIES

Fig.5

Fig.7
Featured Articles ◆ 9

ent Status
st‐Primary
entials:fits versus
dvantagesthat at the very bottom, only 21 individuals
took the radiologist assistance examination.
So, there is a smaller number of individuals
being prepared to become, at least at this time,
radiologist assistants, and I am going to spendsome time speaking more about that particularclassification and the job responsibilities. It
might be interesting just to know the salaryor the annual compensation for technologistsof the various sorts in the United States. So, I
took a sample just before I left to come here to
give you an idea of what the salaries are like(Fig.8).
For radiographers, you will see that the
average salary is $57,865. And just to give you
a comparison, 1 dollar in US is 108 yen today;
I looked it up before I came this morning. So

ANNUAL COMPENSATION – 2019 [SAMPLES]
RADIOGRAPHY$57,865
NUCLEAR MED$83,385
RAD. THERAPY$89,159
MAGNETIC RES.
$76,177
SONOGRAPHY$77,825COMPUTED TOMO $65,775
MAMMOGRAPHY $69,896
RAD. ASSISTANT $108,494
NOTE: 70.4% of the respondents were staff technologists.
The average age = 45.4 years old, 77.2% female, ~52% highest degree isan associate degree, average years in the radiologic sciences is 17 years

Fig.8

10 ◆ Journal of JART English edition 2020

that is the rate of exchange. And you can see
the rest of the salaries. It looks like the highest
is radiation therapy, 89,159, and the radiologist
assistants is 108,494 dollars. So that is just the
average salary. If you have been in the fieldmuch longer time, the salary is higher thanthat. But I just wanted to give you a sense of
the differences. When they did this survey inthis past year, 70.4% of those surveyed werestaff radiographers, so the largest number thatparticipated in the survey were technologists.
The average age was 45.4 years old, 77.2%
were female, about 52% had their highest
degree at the associateʼ s degree level, andI am just telling you for a moment, in the
United States, there are several routes that one
can take in terms of their academic levels to
become a diagnostic radiographer. You cangraduate from a hospital and get a certificate.
You can graduate from a two-year degree
program and have your associate degree.
A four-year program will offer you thebaccalaureate degree and then beyond that,technologists will have the masterʼs degree andfewer technologists will have their doctorate
degrees. But most of those that pursue adoctorate degree are either going teachingor research, and some are in management
roles. So, my particular degree is a PhD in
higher education administration. So, it is not inradiologic science, but my desire was to be inhigher education, to work as a professor anda dean in a college and university. So that was
the direction that I personally pursued.
I am going to spend a little bit more time
focusing just on the radiologist assistant or in
the US they may be referred to as a radiologist
extender. They are advanced ‐ level radiologic
technologists who have advanced or enhanced
patient care but that enhance patient careby extending the capacity of the radiologist,
the physician, in the diagnostic imaging
environment. So, radiologist assistants haveent Status
st‐Primary
entials:fits versus
dvantages

Current Status of Post-Primary Credentials: Benefits versus Disadvantages

been around in the United States for the last
10 years. But I would say that more and more,they are becoming a vital part of the radiologic
team in hospitals and clinics across the UnitedStates. Radiologist assistants must first becredentialed as a registered radiographer
through the American Registry of RadiologicalTechnologists or the ARRT (Fig.9). So, this is apost-primary credential. They are experienced
radiographers who have completed advanced
academic studies through an accredited
radiologist assistant program that utilizes thenationally recognized curriculum. So, there
is a very specified curriculum for the RA
candidates. They must complete an extensive
clinical preceptorship directed by a radiologist.
So, they are very closely connected withworking with the radiologists in this particularrole.
Upon completion of the program, thestudents then take the RA certification examthat is offered by the ARRT and once they
become a registered radiologist assistant, theymust continue their education. So most of us
that are coming to conferences like this realizethat just because we may have graduated fromschool 3, 5, 20 years ago, or 40 years ago likeme, we still have to keep our educational
standards up and keep our knowledge up

Current Status
 Experienced, registered radiographers of Post‐Primary Completed an advanced academic program
Credentials:
Nationally recognized RA curriculum Benefits versus
Radiologist‐directed Clinical Preceptorship
Disadvantages

RA’s Background: Successfully passed the RA Certification
Examination offered by the ARRT Fulfills continuing education requirements

Fig.9

because the technology and our radiologic
science is advancing day after day. Before
coming here, I had a chance to sit in on threelectures upstairs or in the other building withtechnologists that presented on a numberof categories. And I just have to say that thequality of the presentations that I have cometo hear, when I have been to Japan, this is mythird time, are very high level. So, you shouldbe very proud of yourself for what you do here
for keeping the Japanese technologists up to
speed. So, I salute you for doing that.
This is a quick, very high-level summary(Fig.10), the addition of RAs to the radiology
team helps improve productivity and efficiency
at the time when the demand for medical
imaging services is soaring. In the United

RA’s Role – High Level Summary Performs Fluoroscopy and selectedradiology procedures
 Patient Assessment
 Patient Management
 Initial Evaluation of Diagnostic Images
 Not the “final written report”

Fig.10Featured Articles ◆ 11

ent Status
st‐Primary
entials:fits versus
dvantages

States, the number of requests for radiology
services is going up so high. So, I would say
especially for those services that are provided
by the radiologists, the radiologist assistants
are vital to making sure that they are very
efficient. The RA works under the supervisionof a radiologist to provide direct patientcare. They perform fluoroscopy and selectedradiology procedures, patient assessment,
patient management, and the initial evaluationof the diagnostic image. However, in the
United States, the RA does not provide thefinal or the official interpretation or the final
written report and that is provided by theradiologist. The radiology department teamoverall benefits by having RAs available. For
example, the average radiologist workload in
the United States was 14,900 procedures. Thishas been an increase of 7% between 2002 to2003 and 34% increase since 1991 and 1992
(Fig.11). So again, the number of proceduresthat have been asked for in radiology has
increased and the workload of the radiologist
is vastly increasing. So, in this case, theradiologist assistant can relieve the workloadof the radiologist by performing exams that theradiologist is not always available to perform,
increase productivity by freeing up radiologists
to perform the more invasive proceduresthat are not within the RA scope of practice,

Radiologist’s workload was 14,900 Current Statusprocedures, an increase of 7% betweenof
2002‐
Post‐Primary
2003 and 34% since 1991‐1992
Relieve exam workload of radiologists
Increase productivity for department overallImprove overall efficiency of the team
Improve patient access to timely radiologic care

The major responsibilities for the radiologist
assistant is to take a leading role in patientmanagement and assessment. Again, perform
selective radiology examines and procedures
under the supervision of a radiologist. And
then again like I said evaluates it for image
quality, makes the initial image observations
and forwards those to the supervisingradiologist (Fig.12). The RA, I think many ofus as medical imagers are those that have been
taking x-rays for a long time become very goodat looking at images, not just for quality, but
we can make, a lot of us are able to make an
initial diagnosis. We do not ever say anything,
but we know when we are looking at a chest
x-ray that has a density in this area, we prettymuch know what it most likely is. But theRA, the radiologist assistant, takes it a little
bit further and through differential diagnosis
will come up with the initial findings on those

RA’s Major Responsibilities –Why RA’s (benefits)‐

RA’s canimprove efficiency by allowing radiologist to
spend more time on image interpretation anddiagnosis, and improve patient access to timely
radiologic care by expanding workflow andcapacity. So, the radiologist assistant is theprofessional that can step in for the radiologist,
let them do other exams, and the radiologist
assistant can take on a lot of the work that theradiologist would have been doing in the past.

Credentials:
Benefits versus
Disadvantages

Fig.1112 ◆ Journal of JART English edition 2020

 Takes leading role in patient management
and assessment.
 Performs selected radiology exams andprocedures under the supervision of aradiologist.
 Evaluates for image quality, makes initial
image observations and forwards those to
the supervising radiologist.

Fig.12

ent Status
st‐Primary
entials:fits versus
dvantages

Current Status of Post-Primary Credentials: Benefits versus Disadvantages

images, but the radiologist, again, does the
final interpretation. The radiologist assistanteducational requirements, there are different
RA programs (Fig.13).
Most of them in the United States are at themasterʼs level, but there are very few that areat the baccalaureate level. But minimally, theymust graduate with a bachelorʼs degree. The
majority of the programs, they are masters. The
length of the programs is anywhere between
two to two and a half years, and the clinicalportion of their training and their education
is at least a year and a half or 18 months. So,
there is a very large component of clinicalwork that is required to become an RA. The RA
programs require instruction in systematicallyevaluating static and dynamic images fornormal anatomy and physiology. They lookfor normal variants as well as variations inappearance that may indicate pathology. Mostof us, I would say for radiographers, we canlook at an image and see a change in density
or notice something that looks pathological,
but the radiologist assistant goes throughmore education and experience in the actualinterpretation of what those changes may belooking like. So, it is a little bit more thanjust recognizing a change, it is actually going
through more, again, differential diagnosis.

RA Educational Requirements:
Minimal requirement = baccalaureate

Current Statusof Post‐Primary
Length of programs = 2.0 – 2.5 years
Credentials:
Clinical portion = ~ 18 months
Systematically evaluating static &Benefits
dynamic versus
imagesDisadvantages

Majority of programs today = masters

Normal variants
Pathological changes

This is the listing of the core courses thatmake up the curriculum for an Accredited
Radiologist Assistant Program in the UnitedStates (Fig.14). As you can see, the range ofcourses is quite comprehensive and focusedon advanced topics from patient assessment
and patient management, clinical decision
making, radiation safety and radiation biology,
it has correlation with anatomy and pathology,
legal and professional standards, all of thisaccumulates with extensive time with theradiologist acting as a mentor and supervising
the clinical experience. So, the way I look at
it is that those that are in the RA programs
are pretty much similar to a full-time fellow
radiologist, so they are almost like sitting withthe radiologist as a trainee to be a radiologist.
But the RA is right there with the radiologist
looking at the images and listening to thediagnosis and being consulted when theradiologist is making that final diagnosis.
In practice, radiologist assistants perform
a wide range of patient care activities andradiographic procedures ( Fig.15 ). Much ofthis will have a lot to do with the type ofexperiences they have during the radiologist
preceptorships and the type of practice thatis run by the radiologist. So, these are thekinds of things that the RA will participate in,

CORE CONTENT FOR RA
CURRICULUM
 Patient Assessment,
Management and Education
 Pharmacology and Clinical
Decision‐Making in Radiology
 Contrast Media Clinical Pathways Related toBest Practice Imaging
 Report of Findings andValidation of Clinical Practice Research and Professional
Development

 Pathophysiology

 Legal, Professional Standards,
Governmental Standards

 Radiologic Procedures
 Modality and ImageManagement
 Radiation Safety, Radiobiology
and Health Physics

Fig.13

 Image Correlation with
Anatomy, Physiology andPathology

 Radiologist Mentored ClinicalExperienceFig.14
Featured Articles ◆ 13

ent Status
st‐Primary
entials:fits versus
dvantages

taking histories, doing physical exam, they
will be very active in patient follow up, they
will evaluate our laboratory work that is run
on the patient, and they will consult with thepatient to talk them through the proceduresthat they are going to be performing. And
these are the kinds of procedures that many of
our RA colleagues are involved with: lumbar
punctures, GI studies, arthrogram studies,
venograms, arteriograms, thoracentesis,
cystograms, feeding tube placement, they
will be right there to help interpret CT examsof the head and body, MRI exams of thehead and body, and much, much more. So,
depending on the practice of the radiologist,
the radiologist assistant will be right there withthem participating in the doing the procedures,
following up on the procedures and thenfinally, giving their first initial review of thefindings for those procedures.
In the United States, we have 50 states andeach one of those states has the ability to comeup with the requirements for licensure for their
particular state (Fig.16). If you go to UnitedStates, we all do not do the same thing thesame way. So, I am from St. Louis, Missouriside, I live in the state of Missouri, but theother 49 states can have laws that are different
than the way that we license or recognize these

RA Patient Care
Activities
 Histories
 Physical Exams
 Patient Follow‐up
 Lab Workup
 Procedure Consults

radiologist assistants. So, I will tell you that 31of the 50 states currently license and recognize
radiologist assistants. State laws or procedures
determine RA scope of practice. So again,
the scope of practice can be slightly different
depending on what state the RA is working.
So that can be a little bit of a problem if an RA
wants to travel from one state to the next, theyneed to make sure that if they want to leave
California and go to Texas, that the regulationsin Texas are satisfactory for the kind of practicethat they want to do when they move there.
So unfortunately, whilst the RA increases
access of care for patients, especially in rural
areas, by allowing radiologists to work in amore productive manner, so we are findingthat RAs get to practice at a higher level inmore rural communities, communities that do
not have as many physicians or radiologists.
Unfortunately, though, there are still limitations
in some states that limit the ability for RAs
to fully and effectively practice. And thisunfortunately can have a bit of an adverse
effect on patient care. This is one of the
problems that we have in the United States
for RAs. But at the federal level, we havewhat is called the MARCA or the Medicare
Access to Radiology Care Act and this is afederal legislation that widely supports for

Procedures Lumbar punctures
 GI studies
 Arthrogram studies
 Venogram studies
 Arteriogram studies
 Paracentesis/
thoracentesis
 Cystograms Feeding Tube placement CT head & body
 MRI head & body And much more……

Current Statusof Post‐Primary
Credentials:
Benefits versus
Disadvantages

Fig.1514 ◆ Journal of JART English edition 2020

RA Licensure:Thirty one of the fifty states currently
license or recognize the RA
State laws and standards determine RA
scope of practiceUnfortunately, current reimbursement
policies undermine state authority

Fig.16

ent Status
st‐Primary
entials:fits versus
dvantages

Current Status of Post-Primary Credentials: Benefits versus Disadvantages

organizations that are national radiographer
societies, radiologist, and physician extenderorganizations ( F i g . 1 7 ). This particularlegislation is well supported by the ASRT,
ARRT, the American College of Radiology, andthe Society for Radiology Physician Extenders.
Currently, Medicare payment policy allows
RAs to perform medical imaging procedures
only if they are under the supervision of aradiologist. So that is the thing to consider. In
order for insurance to pay for the services ofa radiologist assistant, they must have theirwork under the supervision of a radiologist.
So, the radiologist has to sign off on the
final imaging. And then finally, the use ofphysician extenders is likely to increase andthe knowledge level and care that the RA
provides will greatly benefit our patients andtheir access to radiological services. So, I see
the use of radiologist assistants growing in theyears to come.

for some professionals in medical imaging.
The quick answer is, it is not very easy tocome to the United States and practice yourspecialty of radiologic technology and medical
imaging. It used to be a lot easier many years
ago. But today, it is quite challenging forsomeone from outside of the US that may bevery well credentialed in their country, butwant to come to the US, it is not easy to dothat. Prior to January 1, 2000, special eligibility
was the typical route for candidates educatedoutside of the United States to take the ARRT
certification exam (Fig.18). It was a case bycase evaluation and candidates would haveto provide the necessary documentation of
educational and experiential preparation.
There was not really a standard way ofevaluating or being able to say yes, you cancome from your country to the United States. It
was evaluated case by case, person by person,
and I would say that posed the problem for
many, but today it has not gotten any easier.

Now, sometimes I get the question about
the transfer ability of a technologist educatedin a different country that wants to work in
the United States. So, this question often arises
from colleagues that are seeking to work in
the US. Typical questions about transferring
credentials from other countries is of interest

So, for today, in order to take the ARRT
certification exam, if you are outside of theUS, you must graduate from programs thatare recognized by the ARRT. You must seek
advanced placement in an accredited program.
So, upon meeting the programʼs graduation
requirements and receiving the program ʼ s“SPECIAL ELIGIBLITY”

Federal Legislation
Medicare Access to Radiology Care ACT Current Status
MARCAof Post‐PrimarySupported by
Credentials:
American Society of Radiologic Technologists
Benefits versus
American Registry of Radiologic Technologists
Disadvantages
American College of Radiology
Society of Radiology Physician Extenders

Fig.17

Prior to January 1, 2000 – “special eligibility” wasthe typical route for candidates educatedoutside the United States to take the ARRT
certification examinations.
Case by case evaluation
Candidates would have to provide necessary
documentation of education and experiential
preparation.

Fig.18Featured Articles ◆ 15

ent Status
st‐Primary
entials:fits versus
dvantages

final endorsement, a candidate may apply for
the ARRT certification exam (Fig.19). Whatindividuals, what professionals outside thecountry have done, there are programs in
the United States that do accept colleagues tocome to their program. They will do advanced
placement. So instead of taking maybe twoyears for them to graduate from the program,
you will get an advanced standing, and maybe
it will just take you one year and they will kindof expedite your going through the program,but you must graduate from a program
recognized by the United States or by the ARRT.
You know, whatever advances take placein our profession, there are at least somedownsides or disadvantages that comealong with it, but only really a very few. The
disadvantage that I can see is that there is alittle bit of a fragmentation of our profession
and sometimes accompanying that will be aloss of identity due to the number of titles
within medical imaging (Fig.20). So, letʼs justtalk about that for a second. In the UnitedStates, I told you when I graduated, I becamea registered technologist in radiography andmy credential was RTR, registered technologist
in radiography. But there are other names forwhat I do, in the United States, in the historyof our profession, so we could be called an

Today’s ARRT Certification Requirements for
Foreign Educated Candidates
“Graduates from programs that are not
Current Statusaccredited by a mechanism acceptableof
to Post‐Primary
the
ARRT must seek advanced placementCredentials:
in anaccredited program.”
Benefits versus
“Upon meeting the program’s graduation
Disadvantages
requirements and receiving the program’s final
endorsement on the application, the candidate
may apply for the ARRT certification
examination.

Fig.1916 ◆ Journal of JART English edition 2020

x-ray technician, an x-ray technologist, aradiologic technologist, a medical imager, aradiographer. There are so many different titles
for who we are. The disadvantage is that we do
not use, we have not always used a standard
name for who we are. Now, think about withthe different post-secondary, post-primarycertifications, there are even more different
types of titles for us. There are individuals who
instead of calling themselves a radiographer
with the advanced certification in computed
tomography, they will call themselves acomputed tomography technologist or a
CT technologist. Instead of saying, I am aradiographer with advanced certification inmagnetic resonance imaging, they will referto themselves as an MRI technologist. And I
am just talking about the disadvantages in the

Current Status of Post‐Primary Credentials:
Benefits versus Disadvantages
Fragmentation of the Profession
Loss of Identity – Due to the numberof titles within medical imaging

Fig.20ent Status
st‐Primary
entials:fits versus
dvantages

Current Status of Post-Primary Credentials: Benefits versus Disadvantages

United States.
There may be different kind of standards
in other parts of the world. So, I am only
speaking for the US. For us, with all of ourdifferent titles, and once we have gone into
an advanced certification, we do not go backand refer to our base, our foundation as aradiographer. We leave that to the side, and wecall ourselves by our advanced certification.
And let me just give you a comparison. In the
United States, if a nurse graduates and goes
into some specialty training, becomes a nurse
practitioner, you will hear them always refer tothemselves as a nurse practitioner or a primarycare nurse, where we may be the only onesin the US that leave our original title behindand refer to ourselves as the advanced title. So,
I see that as a disadvantage and it disturbed
me a little bit, but it also causes us to lose ouridentity, especially when we are trying to makeourselves known to the outside community.
I will come back to this part on questions,but I wanted to go to the next slide firs
(Fig.21). You know, this is my third time to
Japan. I was here many, many years ago, when
I was a delegate in the IRRT, representing
the United States, and I was sharing with thepresident that my first time here was when

Dr. Michael D. Ward – 13th
ISRRT PRESIDENT 2010‐2014

11

12

Dr. Nakamura was the president of ISRRT andthen about eight years ago. I put this slide
here not to pat myself on the back, but justto say that I had the pleasure of serving our
profession as the 13th President of the ISRRTand I was the first one to be president from theUnited States. Prior to my presidency, the 11th
President is Dr. Tyron Goh from Singapore,and the 12th President was Mr. Robert George
from Australia.
And after me, it was Dr. Fozy Peer fromSouth Africa and the second president of ISRRT
from the United States is now the current
president, Donna Newman. But I am looking at
friends that I have known for a long time andagain, your president and I have been friends
for a very long time. But I got to tell you, I
am so proud to be a radiologic technologist. I
am proud that I have had the opportunity toserve with some very fine individuals on the
council, on the board of management. I havelifelong friends that when I come to Japan,
there were faces that I have seen at a lot ofdifferent conferences and it makes me feel very
proud and very happy to be a part of what I
would say is a brotherhood and a sisterhoodof professionals that we all may look different.
The thing that brought us into the profession
is our desire to take care of patients and toprovide high quality imaging and radiologic
science care for our patients and their families.
That is the thing that has brought all of us
together.
I have had the chance to go across the world
to represent our profession, and everybody
that I have run into in our radiology family, allcare so much about what we do and I haveseen the pride that is in every one of our faces
when we stand up in front of a group andtell people that we are part of the radiologic
science family.

Fig.21Featured Articles ◆ 17

Note: This article is secondary publication, the first paper was published in the JART, vol. 66 no. 799: 40-43, 2019

Future collaboration with the European
Society of Radiology and European
Federation of Radiographer Societies
Naoki Kodama, Niigata University of Health and Welfare

Approach from the European Societyof Radiology

next ECR and wanted to discuss future collaborations. JART accepted the proposal.

In January 2017, the secretariat of the European Society of Radiology (ESR) emailed theoffice of the Japan Association of RadiologicalTechnologists (JART). In April, the president of
ESR Dr. Bernd Hamm arrived in Japan and requested a meeting. I was unaware of the context of the discussion but decided to have themeeting on April 14, 2017.
On April 14 at 01:00 PM at the Yokohama
Washington Hotel, we had a meeting with theboard members of JART and ESR president Dr.
Bernd Hamm. The main content of the meeting was the consideration for promotional activities for radiological technologists at my association because the president wanted to participate in many meetings of Japanese radiological technologists in the European Congressof Radiology (ECR). In addition, the board
members of JART wanted to participate in the

Promotional activities by ECR 2018
As a promotional activity of ECR 2018, JART
published information on ESR and ECR 2018 in
JART magazines and newsletter and publicized
it widely among the members. ESR launched acorresponding membership system this year. It
is a program that exempts radiographers andradiological technologists outside European regions from the membership fees of ESR. These
members are entitled to free access to magazines, such as European Radiology, Imaging in
Insight, and European Radiology Experimental. Moreover, upon registering for the corresponding membership of ESR by August 31,
the registration fee for participation in ECR was
discounted from the normal registration fee forparticipation.
Since 2018, the Shape your Skills program
has also been held. Authors are exempt fromthe registration fee of ECR 2018 and an additional 200 euros if their abstract is accepted by
the Shape your Skills program. This greatly benefits the Japanese radiological technologists.

Our participation in ECR 2018

Figure 1 Meeting in Japan18 ◆ Journal of JART English edition 2020

We participated in ECR 2018 held from February 28 to March 4, 2018. A meeting between
ESR and JART was held on February 28, 2018.
During the meeting, the number of registered
Japanese radiological technologists for ECR
2018 was 126, an increase of approximately

Promotional activities for ECR 2019

Figure 2 ESR Presidentʼs Office

43% from the previous year, and the number of
abstract subjects registered by Japanese radiological technologists was 119, an increase of
approximately 20% from the previous year.
The reported increase made the participantsvery grateful. As for the number of acceptedJapanese radiological technologists, 11 out of
14 subjects were accepted by the Scientific Paper and 87 out of 105 subjects were acceptedby the Electronic Presentation Online System(EPOS). This was the second place in the national ranking of radiological technologists. He
said he would like to continue promotional activities in cooperation with JART from the next
fiscal year.
We had a meeting with the European Federation of Radiographer Societies (EFRS) on thesame day. EFRS was established in 2008 andcurrently has 32 European countries, 38 academic organizations, and 49 educational institutions, representing approximately 100,000 radiographers or radiological technologists. The
former president Dr. Håkon Hjemly delivered
an invited lecture at the 33rd Japan Congress ofRadiological Technologist (Hakodate). Since
2018, Dr. Jonathan McNulty from Ireland has
been the appointed president. We discussed
the educational system for radiological technologists in Japan and Europe, especially forthe postgraduate education of radiographers orradiological technologists. We agreed to discuss the enhancement of education in the future in cooperation with JART and EFRS and to
hold regular meetings.

Since last year, promotional activities for ESR
2019 have included publication of information
on ESR and ECR 2019 in the JART magazine,
newsletter, and mailing list, and have been
widely disseminated to the members. Upon
registering for corresponding membership of
ESR by August 31, the registration fee for ECR
2019 was discounted from the regular registration fee, resulting in a final registration fee of
99 euros. JART has decided to encourage participation in ECR, including ECR in the target
academic societies for overseas presentations.
In addition, there was a proposal from ESR
to select 100 subjects that Japanese radiological
technologists are interested in from the ECR
Online streaming platform, translate them into
Japanese at the ESR, and make them available
to the Japanese radiological technologists. ECR
Online is a streaming platform that can be accessed for free until ECR 2019 From the presentations of ECR 2018, mainly from the JARTInternational Committee, we selected 100 presentations that Japanese radiological technologists would be interested in and sent them to
ESR in May 2018.
In addition, ESR will create Radiographersʼ
Lounge in ECR 2019, so the installation of afree-of-charge JART booth and setting-up of aJapanese session in the Voice of EPOS session
were proposed, and JART accepted the proposals. The Japanese radiological technologists
submitted an abstract, selected 16 subjects
from the accepted subjects, and set-up a Japanese session for the Voice of EPOS.

Voice of EPOS Japanese session at
ECR 2019
At ECR 2019, which was held from February
27 to March 3, 2019, the Radiographersʼ Lounge
installed the International Society of Radiographers and Radiological Technologist (ISRRT)
booths and booths for radiographers or radiological technologists in various countries. JART
booths have also been installed in the sameway. At the JART booth, members selected for
Featured Articles ◆ 19

Figure 3 At the ISRRT booth, with ISRRT President
Ms.Donna

Figure 5 Voice of EPOS Japanese Session

Figure 4 Awards ceremony

Figure 6 ESR Director, Dr. Bernd Hamm

travel support grants were awarded. The Voiceof EPOS Radiographer stage was set-up rightnext to the Radiographersʼ Lounge, where sessions of the Voice of EPOS were held everyday. The Japanese sessions of the Voice of
EPOS (VoE-130, VoE-139) were held on February 28 and March 1. The president Dr. Nakazawa chaired the session for two days, andJapanese radiological technologists presented.
As the first attempt at ECR 2019, an interview
was conducted at ESR Connect Studio. This interview was conducted for ESR presidents andrepresentatives of each organization. In the interview with JART, president Dr. Nakazawa
asked about the Japanese session of the Voiceof EPOS, impression of the Radiographersʼ
Lounge, and promotional activities for Japanese radiological technologists.

20 ◆ Journal of JART English edition 2020

Cooperation with ESR, EFRS, andISRRT at ECR 2019
At ECR 2019, JART held many meetings withother organizations, such as ESR, EFRS, andISRRT. At the meeting with ESR, 697 members
from Japan registered for ESR corresponding
membership. As for the accepted number of
abstracts by Japanese radiological technologists at ECR 2019, the Scientific Paper accepted
6 out of 13 presentations, and EPOS acceptedFuture collaboration with the European Society of Radiology and European Federation of Radiographer Societies

Figure 7 EFRS president, Dr. Jonathan McNulty

Figure 8 After ISRRT informal meeting

90 out of 105 presentations. As in the previous
year, these radiological technologists ranked
second in the country. In addition, 26 Japaneseradiological technologists were selected for the
Shape your Skills programme. ECR 2020 will
be held in Vienna, Austria from March 11 to 15,
2020, and the deadline for abstract submission
is October 10, 2019.
Since last year, we have been holding meetings with EFRS. President Dr. Jonathan McNulty, vice president Ms. Charlotte Beardmore, finance director Mr. Vasilis Syrgiamiotis, andother board members discussed the Radiographer Practitioner, graduate education for radiological technologists, especially the doctoral
course. We decided on another meeting at ECR
next year.
We participated in an informal meeting with
ISRRT Society Membersʼ leaders during ECR
2019. At this meeting, issues related to the revision of the ISRRT annual membership fee,
which was currently a concern, and the global
status of radiological technologists were dis-cussed. After the meeting, ISRRT president Ms.
Donna asked us to send a symposiast to Japanto hold an ISRRT meetʼs Asia Session at ECR
2020.

Conclusion
JART will continue to work with ESR, EFRS,
and ISRRT to encourage members to participate in ECR. Planning sessions of the ECR andJapanese sessions of the Voice of EPOS will beheld. In addition, based on the discussions
with ESR, information on ECR 2020 will be
conveyed to members through the JART magazine, newsletter, mailing list, and so on. We
would like to make various requests to ESR forthe benefit of JART members. I hope that manymembers will participate in ECR 2020.

Acknowledgements
We would like to thank Editage (www.editage.com) for English language editing.

Featured Articles ◆ 21

Arts and Sciences
the original work

Received June 8, 2018; accepted August 31, 2018

A Survey of Factors Inf luencing the Working
Conditions of Radiological Technologists in Japan
Hiroe Muto1），2）, Kanae Matsuura1），2）, Satoshi Nakanishi1），2）
1）The Japan Society of Education for Radiological Technologists2）Dept. of Radiological Technology Faculty of Health Science, Suzuka University of Medical Science

Note: This paper is secondary publication, the first paper was published in the JART, vol. 66 no. 795: 17-25, 2019.
Key words: radiological technologists, starting salary, degree holders, work environment, environment improvement【Summary】

The purpose of this research is to contribute to the realization of a stable relationship between supply and demand
regarding radiological technologists (RTs). We investigated the information provided on recruitment vouchers (numberof job postings, initial salary, preference given or not given to holders of higher education degrees, holiday system,etc.) and analyzed the supply and demand trend regarding RTs. Results indicated that the demand for RTs is generally
steady. However, the starting salary had decreased from our 2014ʼs survey. There was also a regional difference instarting salary. In the short term, the ratio of supply and demand situation is stagnant or is falling slightly due to anincrease in the number of RTs. However, facilities that give preferential treatment to degree holders have reached 60%
in hospitals, so future demand for degree holders will rise.

1. Background and purpose
According to the population prediction of
the Ministry of Internal Affairs and Communications Statistics Bureau 1), the total populationof Japan as of October 1, 2017 was 126.7 million. In Japan, the 0-14-year-old population
has decreased, while the population of those
aged 65 years or older has increased, with theresult that after 1997, the older population exceeded the juvenile population in number. The
juvenile population rate is now 12.3%, the lowest it has ever been, while on the other hand,
the rate of the number of people aged 65+
population is record-high of 27.7% 1).
According to the White Paper on the Ageing
Society issued by the Cabinet Office in 2016,
approximately half of all people in Japan over
the age of 65 now complain of some subjective
symptoms about ill-health, and for one out offour people, this affects their daily life. It is
expected that the demand for healthcare professionals who support older people who areprone to illness will increase 2).
There have been advancements in health-22 ◆ Journal of JART English edition 2020care. Additionally, there have been changes in
the medical needs of the public.
There have therefore been attempts to enhance team healthcare delivery that is performed by various medical staff who complement and cooperate with each other so as topractice their specialty most effectively. As aresult, the scope of work of radiological technologists (RTs) has also increased 3-6). RTs arebeing trained in educational institutions suchas four-year universities, which account for approximately 70% of all of the institutions offering such courses.
Regarding healthcare, a current problem isthe lack or uneven distribution of medical staff
across the country. The estimated number ofnurses for 2025 is also expected to be insufficient according to a report 7) presented in “theconference for the seventh projection of theestimated supply and demand of nursing personnel” held the Ministry of Health, Labr andWelfare (MHLW) of Japan. The Japanese Nursing Association continuously conducts surveys
to determine the supply and demand or thework situation of hospital nurses as well as tothe original work
A Survey of Factors Influencing the Working Conditions of Radiological Technologists in Japan

gather information regarding the retention ofthese nurses 8).
With regard to RTs, however, although some
reports on the supply and demand for RTs
have been delivered 9-12), no studies have focused on RTsʼ starting salary, conditions of employment for females, or educational background. We therefore aimed to investigate thecurrent status regarding the supply and demand and working conditions of RTs 13).
Employment of women as RTs is a further
issue for investigation. In recent years the social participation of women has progressed,
and peopleʼs way of life has diversified. However, efforts to support womenʼs advancement
in society, such as reduced working hours andchildcare support, have not progressed. The
Work-Life Balance Charter 14) was devised by
the Cabinet Office to improve this situation.
In this study, we investigated the number ofjob postings, the salary, regional disparity in salaries, and regional disparity in supply and demand. The purpose of this study is to contributeto ensuring a stable future for RTs throughmaintaining demand and improving working
conditions.

2. Subjects and methods
The present study was conducted on 648 job
postings that were sent from medical institutions to the Suzuka University of Medical Science between April 1, 2016, and March 31,
2017. One job posting was also sent from a
non-medical institution, which was excluded
from the present study.
The following 11 items were investigated:①receipt date of the job posting, ②location of
institution (prefecture), ③category of institution(hospital, clinic, or other), ④employment pattern (full-time, part-time, fixed-term, etc.), ⑤
conditions regarding the employment of women (only women employed or given preference), ⑥restriction of application according to
educational background, ⑦differentiated start-

ing salary according to educational background,⑧payroll system (monthly salary, annual salary,etc.), ⑨base salary, ⑩qualification allowanceor extra allowance, etc. ⑪holiday system.
The results were analyzed to examine thefollowing aspects: employment overview, requirements for employment (enhanced employment of women), salary based on payroll
system, and starting salary based on educational background.
Subsequently, we identified the number of
examinees taking the national examination for
RTs in the fiscal years 2006 to 2016, as well as
the pass rate, to support the discussion on the
supply and demand for RTs.
Based on the findings, the outcomes of various statistical surveys.
conducted by the MHLW, the Ministry of Internal Affairs and Communications, or the professional associations of physicians, nurses,
and others were examined.
Facilities that did not clearly provide information on certain sections of their job postings,
such as their starting salary or requirements for
employment, were excluded from each analysis. Statistical processing was performed using
IBM SPSS Statistics Ver.22, which included basic descriptive statistics, a homogeneity analysis,
the Mann-Whitney U test, and the Kruskal-Wallis test.

3. Results
3-1 Conditions regarding the demand for RTs
3-1-1 Number of job postings

The number of monthly job postings in thefiscal year 2016 is shown in Fig.1, which also
shows the number of job offers for 2013 (575cases in total) and 2015 (707 cases in total) as
a comparison 9), 13). In April 2016, 41 job postings were sent to the Suzuka University of
Medical Science, and the number increased
thereafter, peaking at 85 in July. The numberof job offers in July and August decreased from2015, but there were more job offers in SepArts and Sciences ◆ 23

Fig.1 Total number of job postings / monthFig.2 Number of entities of job postingstember and October than 2015. In Fig.1, ablack bar graph was added to represent the
number that excluded the overlapping of job
recruitment caused by recruitments from thesame facilities. After the exclusion of the overlapping items, the total number of job recruitments was 574.
The job postings were then categorized by
prefecture, as shown in Fig.2. In the present
study, job postings were sent from all 47 prefectures in Japan and were included in theanalysis.
3-1-2 Promotion of efforts to employ women

The job postings were checked for descrip-

24 ◆ Journal of JART English edition 2020

tions such as “recruitment of women”.
The results showed that only 42 facilities(7.3%) specified their conditions for the enhancement of female RT employment, withterms such as “women are preferred in provision of mammography services” or “womencandidates preferred”. The remaining 532 facilities (92.7%) described no specific conditions
for employing women. In 2013, 37 facilities(6.4%) specified conditions for employment of
women, while in 2015 39 facilities (5.9%) did
so. Little change was thus observed in four
years from 2013 to 2016.

the original work
A Survey of Factors Influencing the Working Conditions of Radiological Technologists in Japan

3-1-3 Requirements for employment based on
educational background and payroll system

The job postings were checked for restrictions on employment and differentiation of the
payroll system according to educational background. Conditions of employment and a salary system based on educational backgroundwere analyzed in 553 cases.
The results are shown in Table 1. A total of
49 facilities (8.9%) stated that students holding
a bachelorʼs degree (hereafter, referred to as
bachelorʼs graduates) or a higher qualification
were eligible to apply, and three of these facilities (0.5%) specified a distinction in the payroll
system between bachelorʼs and masterʼs graduates. Furthermore, 247 facilities (44.7%) did not
differentiate their job postings for employment
but specified the differentiation of their payroll
system based on educational background. Finally, 257 (46.5%) facilities specified no differentiation.
In 2015, 10.5% of these facilities indicatedthat they required graduated in their recruitment conditions, and 39.2% indicated salary differences according to educational background,making a total of 49.7%. In 2013, 3.0% of thesefacilities indicated that they graduated in the recruitment conditions, and 38.1% indicated salary differences according to educational making
a total of 41.1%.
In results based on the type of facility (hospital, clinic, others), 44 (9.4%) facilities specified that they wished to employ graduates witha bachelorʼs degree or higher qualification, and
231 hospitals (49.4%) gave preferential treat-ment in the base salary. Three clinics [9.1%]
and 15 health check facilities [31.9%] differedin their employment requirements or salary
packages.
3-1-4 Employment pattern (full-time, fixed-term,
part-time, etc.)

In 2016, regarding the employment pattern ofRTs, 533 (92.9%) facilities included permanent
full-time staff, 31 (5.4%) included fixed-term
staff, and 10 (1.7%) included part-time staff.
In 2015, permanent full-time staff comprised
95.1%, fixed-term staff comprised 3.3%, andstaff providing part-time service comprised
1.6%, while in 2013, 94.6% were permanent
full-time staff, 3.3% were fixed-term staff, and,1.9% were staff providing part-time service.
3-2 Conditions regarding the supply of RTs(the number of examinees and pass rate
for the national examination for RTs)

Next, the supply situation was investigated.
On the MHLW ʼs reports 15), the number of examinees, the number of candidates who passed,
and the pass rate in the National Examinationof Radiological Technologists since 2006 were
examined, and the yearly trends are shown in
Fig.3 and Fig.4. The following figures are confirmed on the website of the MHLW 15) : Until
2012, the number of examinees in the RTʼs national examination was around 2,500. As from2013, the number increased, reaching 2,939 in
2016. In recent years, because the number ofschools for RTs has increased, the number of
RTs newly graduated from college has increased.
3-3 Conditions regarding salaries and work

Table 1 Preferential treatment at the time of hiring
for a degree acquirer

hours of RTs
3-3-1 Salaries by payroll system (base salary,starting salary)

Among the 574 facilities investigated, 550(95.8%) stated the salary on their job posting.
This was approximately the same as in 2013(93.7%) of and 2015 (96.0%. In 537 [97.6%] of
Arts and Sciences ◆ 25

Table 2 Base salary for new graduates by the payroll system for 2016 versus that for 2015

Table 3 Starting salary for new graduates by the
payroll system for 2016 versus that for 2015
Fig.3 Number of examinees and number ofsuccessful candidate

Fig.4 Pass rate for RT national examination

those facilities, the payroll system for RTs included a monthly salary, while in five [0.9%] it
included an annual salary, and in five [0.9%] it
included a daily salary.
A comparison of base salaries according to
the payroll system (excluding qualification allowance or extra allowance) is presented inTable 2. In the case of facilities offering different salaries according to educational background, the salary for bachelorʼs degree graduates was utilized for the analysis.
The base salary in the facilities adopting amonthly payroll system was 190,095 yen on
average, the median was 189,100 yen, the minimum was 81,650 yen, and the maximum was
265,000 yen. The base salary in the facilities
adopting a daily payroll system was 9,783 yen
on average, the median was 9,619 yen, theminimum was 8,581 yen, and the maximum

26 ◆ Journal of JART English edition 2020

was 12,180 yen. The base salary in those adopting an annual payroll system was 3,231,180
yen, the median was 3,243,900 yen, the minimum was 2,760,000 yen, and the maximum
was 3,600,000 yen. The base salary in facilities
adopting the monthly payroll system in thepresent study was higher than that reported in
the 2015 survey results 13) by 1,161 yen on average and by 2,025 yen according to the median, with no statistically significant differences.
Moreover, the base salary in facilities adopting
the monthly payroll system in the present study
was higher than that reported in the 2013 survey results 9) by 1,066 yen on average, and by
690 yen according to the median, with no statistically significant differences.
The starting salary calculated by adding theextra allowance to the base salary is shown in
Table 3. The starting salary in the facilities
adopting a monthly payroll system was 198,415
yen on average, the median was 195,500 yen,
the minimum was 120,000 yen, and the maximum was 281,600 yen. As for the mean, 3,187
yen, the median decreased by 2,830 yen compared with 2015 with no statistically significant
differences.
3-3-2 Starting salaries by educational backgroundA comparison of starting salary based on ed-

the original work
A Survey of Factors Influencing the Working Conditions of Radiological Technologists in Japanucational background is shown in Table 4. The
starting salary for 45 facilities that stated intheir application requirements that they would
employ applicants holding a bachelorʼs degree
or higher qualification was 197,417 yen on average, the median was 195,400 yen, the minimum was 176,800 yen, and the maximum was
232,645 yen. Among these facilities, three specified a differentiation in the starting salary formasterʼs degree graduates, with an average salary of 212,067 yen for these graduates.
For the 245 facilities that did not specify therequired educational background for application but differentiated the starting salary basedon educational status, the starting salary forbachelorʼs degree graduates was 196,527 yen
on average, the median was 193,600 yen, theminimum was 172,500 yen, and the maximum
was 246,386 yen. The starting salary for professional school graduates was 187,412 yen on
average, the median was 184,800 yen, the minimum was 166,300 yen, and the maximum was
224,419 yen. Among these facilities, 21 specified the starting salary for masterʼs degree graduate, offering 211,549 yen on average, with a
median of 209,900 yen, a minimum of 190,300
yen, and a maximum of 230,000 yen. For facilities that did not specifically limit recruitment
or differentiate the base salary according to educational background, the average starting salary was 200,470 yen, the median was 196,450
yen, the minimum was 120,000 yen, and theTable 4 Differences in starting salary for new graduates by degree for 2016 versus that for 2015

maximum was 281,600 yen.
These results indicated that the starting salary for professional school graduates in facilities
differentiating the payroll system by educational status was lower than that in any other group(P < 0.05).
The starting salary for masterʼs degree graduates in the group of facilities differentiating the
payroll system according to education was
higher than that in the group of facilities that
required a bachelorʼs degree or professional
school qualification (P < 0.05).
We compared the starting salaries of 2015
with those of 2016. The starting salary for bachelorʼs degree graduates in the group of facilities
that required a bachelorʼs degree for the application was lower than last year (P < 0.05). Furthermore, the result for facilities that did not
specifically limit recruitment or differentiate
the base salary according to educational background was lower than 2015 (P < 0.05). The
starting salary for masterʼs degree graduates in
the group of facilities differentiating the payroll
system according to education was higher than
2015 (P < 0.1). The results for facilities that did
not specifically limit recruitment or differentiate the base salary according to educational
background was lower than 2013 (P < 0.05).
3-3-3 Salaries by prefecture (base salary, starting salary)The starting salary for newly graduated RTs
by prefecture is shown in Table 5. In addition
to the average starting salary for each of the 47
prefectures, the starting salaries in facilities employing graduates in wide area, such as the
National Hospital Organization, as well as thenational average, are presented. For the calculation of the average starting salary in facilities
offering a different salary for bachelorʼs degree
graduates, the starting salary for bachelorʼs degree graduates was used. The names of theprefectures are presented in Japanese, with theprefecture identification numbers defined by
ISO 3166-2: JP (in this report, the wide-area
Arts and Sciences ◆ 27

Table 5 Summary of the starting salary differenceby area for 2016 versus that for 2015

blocks and the national average are 00 and JP,
respectively).
In addition, the starting salaries for RTs in thepresent study are presented in Table 5, alongwith the survey results regarding the startingsalaries for the various job types in the medical
and welfare professions (excluding physicians
and nurses) reported in the Basic Survey on
Wage Structure (starting salary) 16), 17) conductedby the MHLW. The starting salary reported in
the Basic Survey on Wage Structure is calculated by subtracting commuting allowance from agiven salary (consisting of base salary and other allowances without overtime compensation)
for new graduates performing regular duties.

28 ◆ Journal of JART English edition 2020

A survey by the MHLW also showed that thestarting salary of RTs in 2016 was lower than in
2015, similar to our findings. In our own survey, in comparison to the previous three years,
the starting salary decreased by 640 yen, whilein the findings of MHLW, it increased by 6,600
yen.
In Fig.5, the shaded area represents the For
47 prefectures where the starting salary was
lower in 2016 than in 2015. The base salary for
newly graduated RTs by prefecture in this investigation ranged from 176,090 yen to 213,244
yen, with a difference of approximately 37,000
yen (prefectures with five or fewer job postings that met the requirements were excluded)(Table 5). In the 2015 investigation, the differ-Fig.5 Summary of the starting salary differenceby areaFig.6 Summary of the starting salary differenceby area in 2016

the original work
A Survey of Factors Influencing the Working Conditions of Radiological Technologists in Japanence in the starting salary of each prefecture
was about 25,000 yen. The area difference inthe starting salary mean tends to have spreadthan in 2015. Furthermore, 16 prefectures had
a starting salary above the national average.
For 47 prefectures, those with a starting salary for newly graduated RTs below the national
average is represented by the shaded area inTable 5. According the results of the 2016
MHLW Wage Survey (medical and welfare,) thestarting salary ranged from 158,900 yen to253,000 yen, with a maximum difference of
94,100 yen.
A comparison of the starting salary for RTs
the results of the 2016 MHLW Wage Survey(medical and welfare) revealed a higher starting salary for RTs (Fig.6).
3-4 Working conditions (holiday system)

In the 574 cases surveyed, the number of facilities where a holiday was shown clearly inan advertisement for a job was 489 (85.2%).
With regard to a holiday system, 61 facilities(12.5%) adopted a five-day working week, 332
facilities (67.9%) adopted a five to six-day
workweek, and 96 facilities (19.6%) adopted asystem allowing for six holidays in four weeks.
We compared the number of facilities that
adopted a holiday system allowing for six holidays in four week, and found that these included 76 hospital facilities (18.5%), eight clinic facilities (25.8%), and 12 medical examination centers (26.7%), as shown in Fig.7.

4. Discussion
We aimed to investigate the current status
with regard to the supply and demand andworking conditions of RTs taking into accountregional differences. The discussion further includes prediction of the supply and demandfor RTs and the general prospects 9), 13) for these
professionals.
In the study, we conducted a continuous survey of the number of job postings, the number

Fig.7 Summary of workweek systemof employment systems, and the supply anddemand trends based on starting salaries, thenational examination passers of RTs, and theeducational background required. In the following section, we analyze the survey results
and consider measures to improve working
conditions for RTs.
The number of job postings examined in thecurrent study will be compared to those included in studies conducted in 2011 and2013 9). The last two months of the fiscal year
2011 were not investigated and were excluded
from this comparison. The job postings werecompared, and results showed that there were
527 job postings in 2011, 575 in 2013, 639 in2015, and 595 in 2016.
The increase in the number of job postings is
considered to have abated. The number of job
openings requiring a college graduate holding
a bachelorʼs degree was 17 in the 2013 survey
but has increased to 49 in this survey, whichsuggests that the demand for college graduates
is increasing.
Next, to evaluate the working conditions of
RTs from the perspective of wages, an analysis
was performed based on starting salary. In the2016 survey, the average starting salary of facilities paying monthly salaries was indicated as
198,415 yen, a decrease of 3,187 yen from thatindicated in the 2015 survey, but there was no
statistically significant difference. Similarly,
there was no statistically significant difference
Arts and Sciences ◆ 29

in comparison with the 2013 survey, indicatingthat in the past four years, there has been no
significant change in the demand for newly
graduated RTs, nor in salaries for these graduates.
At present, the shortage of medical staff andthe uneven distribution of medical care arealso pressing issues 18). We therefore compared
the average starting salary by prefecture in order to determine the status of RTs in each areawith regard to employment conditions. Results
indicated that in 2016, the starting salary between prefectures increased by approximately
37,000 yen from 176,090 yen to 213,244 yen,
and it increased by 12,000 yen compared to2015. In the MHLW survey, the difference between prefectures was 94,100 yen, which was
32,600 yen greater than in 2015.
Regarding the aspect of supply, the numberof candidates who passed the national examination for RTs exceeded 2,500 in 2016. Also,
new schools are expected to open in the next
few years, and supply will increase in the longterm.
Concerning demand, the results of this survey indicated that the demand for RTs wasstrong overall.
On the other hand, however, in the Reporton the Actual Condition of RTs in 2017 19), 20)
issued by the Japan Association of RTs, it isstated that approximately half of the facilities
felt that there were “not enough” medical radiologists. The report further indicates that approximately 40% of facilities have overtime ofmore than 10 hours, and more than 12% of facilities have less than 5 paid days off. Therefore, it is necessary to improve the working
conditions of RTs so as to increase the numbers.
In this survey, approximately 50% of the facilities clearly indicated a salary system based on
educational background. Compared with thelevel in 2013, the number of facilities considering higher education when hiring increased by
12.5%. Moreover, the average starting salary of

30 ◆ Journal of JART English edition 2020

all RTs decreased by 3,187 yen as compared to2015, but there was no statistically significant
difference between the two years. However,
the average starting salary increased slightly
from 2015 in facilities that based their salarysystem on educational background, especiallyin facilities where graduates holding masterʼsdegrees were specified. There was a significant
difference in wage allocation based on educational background, and for facilities where neither application conditions nor education requirements were specified, the wage allocationin 2016 was reduced compared with 2015 and2013. In this study, the amount of the startingsalary according to educational background in
the Actual Condition of RTs in 2017 19), 20) issued
by the Japan Association of Radiological Technologists (JART) 19), 20) is 170,000 yen to 179,000
yen for vocational school graduates with a four
year qualification. The starting salary for those
who graduated from a university increased
from 180,000 to 189,000 yen, and for those whocompleted graduate school with a masterʼs degree, the starting salary increased from 200,000
to 219,000 yen. As is the case in the current
survey, this indicates that the higher the education, the higher the salary that is offered.
However, the report states that it is not clear
whether basic salary settings will increase witheducation 19). In the analysis of recruitment
slips in our study, the results revealed that approximately half of all facilities and about 60%
of hospitals took higher educational degrees
into consideration at the time of recruitment.
From the above results, it is can be concluded
that the demand for degree holders is on therise.
We further considered the future demand for
RTs and considered how to improve working
conditions. One factor is the employment ofdegree holders, as mentioned above. In consideration of the pay raise system adopted ateach facility, it is vital to encourage the employment of individuals holding not only bachelorʼs degrees but also higher degrees such as

the original work
A Survey of Factors Influencing the Working Conditions of Radiological Technologists in Japanmasterʼs and doctoral degrees.
A second factor is the promotion of affirmative action and the development of a working
environment that allows for a variety of working styles to be selected according to the individual circumstances of working people. Whereof different treatment of female and male workers occurs, such as few women being employed
at a workplace or the majority of management
positions being occupied by men, the workplace should engage in “positive action” 21). For
example, a recruitment slip should include arequest for female RTs. These do not violate
the Equal Employment Opportunity Law 21). At
present, the percentage of women employed
in radiation departments is 24.6%, and it is reported that there is a slight increase in thisnumber 20). In Japan, with the number of female
RTs expected to increase in the future, theneeds related to different working styles, including compatibility with childcare and nursing care, are expected to diversify. Therefore,
further promotion of womenʼs employment including positive actions is expected.
Third, related to the above, there is a need to
implement measures for the retention of newor young RTs. According to the Report of theSurvey of Actual Status of RTs in 2017 19), theturnover rate for newly graduated RTs was
2.2% for men and 3.0% for women.
Therefore, measures for staff retention arenecessary. Specific measures include considering the introduction of a standardized education system 19), conducting training for new
staff, and improving the training environment
according to the environment in which people
following various work styles are placed. These
measures should be implemented in the workplace, but it is assumed that it is not feasible tointroduce training of new staff and a standardized education system in small-scale facilities.

JART should play a central role in promoting
activities in cooperation with the Japan Societyof Education for Radiological Technologists(JSERT) and with universities.
In future research, a detailed survey is needed to provide evidence to support improvement in the work environment so that RTs canselect various work styles according to theirindividual circumstances. It is thus necessary to
examine the work style of RTs and their needfor career support, and a fact-finding survey oncareer support initiatives is needed.
The limitation of this study is that it is basedon job postings sent to only one facility. In
order to formulate a more comprehensive supply-demand outlook, we propose that a survey
be conducted in cooperation with JART, theprefectural JART, JSERT, and training institutions for RTs.

5. Conclusion
Concerning the demand for RTs holding
bachelorʼs and masterʼs/doctoral degrees is expected to increase.
In the future, in order to stimulate demandand improve the working conditions of RTs,
the following measures are suggested: 1) employment of degree holders, 2) promotion ofaffirmative actions, 3) improvement of the work
environment so that various working styles canbe selected. In addition, we advocate the implementation of measures for the retention ofyoung RTs.

Acknowledgements
This work was supported by a contract research grant for the fiscal year of 2016, awarded by the Japan Association of RadiologicalTechnologists to the JSERT.

Arts and Sciences ◆ 31

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Arts and Sciences
the original work

Received July 2, 2018 ; accepted October 26, 2018

Optimization of radiation exposure to the eye lensin stereotactic radiosurgery
Kohei Kawasaki1），Osamu Nagano2），Kyoko Aoyagi2），Takahiro Kageyama1）1）Department of Radiology, Chiba Cardiovascular Center
2）Gamma Knife House, Department of Neurosurgery, Chiba Cardiovascular Center

Note: This paper is secondary publication, the first paper was published in the JART, vol. 66 no. 796: 15-20, 2019.
Key words: stereotactic radiosurgery, Gamma Knife, radiation dose, eye lens, cataract【Abstract】

In 2012, International Commission on Radiological Protection (ICRP) published a threshold dose for cataract as
0.5 Gy. However, little evidence is available on determination of radiation dose to the eye lens in gamma knife
radiosurgery (GKS). The purpose of this study was to confirm the fact of radiation exposure to the eye lens andproduce an appropriate treatment plan for GKS. From January 2015 to December 2016, 57 patients (39 women; age, 2784 years) with single lesion of meningioma were enrolled in this study. We retrospectively measured the dose to theeye lens in the treatment plans that have been performed for these patients. To investigate whether a reasonable dose
distribution could be designed we modified the plans regarding the eye lens as organ at risk in the cases that the lensdose exceeded 0.5 Gy. Then we compared treatment parameters between plans before and after modification. As aresult, the maximum dose to the eye lens reached the threshold level for cataract in 13 cases. In the modified treatment
plans for all of these cases, the maximum dose to the eye lens was reduced to less than 0.5 Gy although the irradiation
time was prolonged by 11.6 minutes on average. There was no significant difference in dose covering 95% of thelesion volume (D95). In conclusion, in 23% of patients who underwent GKS, the eye lenses were exposed beyond the
ICRP threshold dose for cataract. Ophthalmological follow-up might be required in these cases. In addition, we could
produce optimal treatment plan with reduced lens dose to less than the threshold dose for cataract while keeping D95
with acceptable prolongation of irradiation time.

1. Introduction
Gamma knife radiosurgery (GKS) is one of
the techniques of stereotactic radiosurgery,which is specialized for intracranial lesions 1).
The steepness of the dose distribution curve of
stereotactic radiosurgery raises concern about
adverse radiation effects. Thus, it is essential
to be cognizant of the spatial relationshipbetween organs at risk of developing side effects, target lesions and the dose distribution.
Therefore, there have been several reports tooptimize the radiation dose to organ at risk inthis field 2-5).
In International Commission on RadiologicalProtection (ICRP) publication 118 6), it was required to pay particular attention to cataract.
The threshold dose for cataract of 0.5 Gy was
proposed, which is drastically lower than previously considered. However, little evidence isavailable on dose optimization for the eye lens

involving the new threshold value in GKS. The
purpose of this study was to confirm the factof radiation exposure to the eye lens in GKS
and produce an appropriate treatment plan toprevent the lens dose from reaching the ICRP
threshold level.

2. Materials and methods
This study was approved by institutional review board (IRB) of our hospital (IRB No. 392).
We took care not to infringe on the patientsʼ
right to privacy by making the data anonymous. All patients provided written informed
consent.
2-1 Patient characteristics

From January 2015 to December 2016, 57
patients with single meningioma were enrolled
in the present study. Patient characteristics
and the location of the lesions are presented
Arts and Sciences ◆ 33

in Table 1. GKS was performed in all the patients using the Leksell Gamma Knife Perfexion(Elekta Instruments AB, Stockholm, Sweden).

Table 1 Patient characteristics
Characteristic

Value

Total no. of patients57

Men/women
Age (years), median (range)

18/39
64 (27-84)

Lesion location
Right/left

29/28

Frontal lobe

21

Temporal lobe

14

Occipital lobe

2

Parietal lobe

2

Cerebellopontine angle

12

Cerebellar hemisphere6

2-2 Confirmation of the fact of radiation exposure to the eye lens

To confirm how much the eye lens was irradiated, we retrospectively calculated the doseto the eye lens in the treatment plans that havebeen conducted for GKS. The peripheral doseprescribed for the lesions was 12.5-18 Gy. In
the cases of the lesion adjacent to the optic
nerve, staged GKS was applied and peripheral
doses of 8.5-9 Gy were prescribed 7). On treatment plan system (Leksell GammaPlan 10.1.1;
Elekta Instruments AB, Stockholm, Sweden),
we newly contoured the eye lens in the original plans and overlaid the dose distribution.
And then, we regarded the eye lens as anorgan at risk and measured following dose parameters: maximum lens dose; mean lens dose;the volume of the eye lens received beyond
0.5 Gy (V0.5). Additionally, we analyzed following factors that might affect the dose parameters: lesion location (anterior, mid, posterior,
ipsilateral and contralateral); lesion volume;
peripheral dose; number of shots; existence ofother organs at risk.

2-3 Optimization of the treatment plan

We further analyzed the cases in which the
maximum lens dose reached the thresholdlevel as a result of Sect. 2-2. We modified theoriginal treatment plans to design reasonable
dose distribution. We intended to make 0.5 Gy
isodose line away from the eye lens withoutcompromising lesion control by employing
a hybrid isocenter technique referred to as
ʻʻcomposite shotʼʼ with collimators of different
sizes that are blocked and mixed. Then, we
compared following dose parameters between
before and after modification: maximum lensdose; dose covering 95% of the lesion volume(D95); irradiation time.
2-4 Statistical analysis

All statistical analyses were performed using EZR (http://www.jichi.ac.jp/saitama-sct/
SaitamaHP.files/statmed.html) 8). We evaluatedthe factors affecting the dose to the eye lens
using multiple regression analysis. We compared the maximum lens dose, the D95 and theirradiation time between original and modified
plans using the Wilcoxon signed rank test. The
significant level was defined as 0.05.

3. Results
3-1 Confirmation of the fact of radiation exposure to the eye lens

The measurement results of the maximum
and the mean dose to the eye lens and the V0.5
are shown in Table 2. The maximum lens dose,the mean lens dose and The V0.5 ranged 0-1.1
Gy, 0-0.8 Gy and 0-276.3 mm3, respectively.
Figure 1 shows the frequency distribution of

Table 2 Measurement of the dose parameters
Dose parameter
Maximum lens dose (Gy)

0.1 (0-1.1)

Mean lens dose (Gy)

0.1 (0-0.8)

V0.5 (mm3)30.4 (0-276.3)

Data are presented as median (range)

34 ◆ Journal of JART English edition 2020

Value

the original work
Optimization of radiation exposure to the eye lens in stereotactic radiosurgery

the maximum lens dose. In 13 cases (23%), theeye lenses were exposed beyond 0.5 Gy whichis the ICRP threshold dose for cataract.
Table 3 demonstrates the result of multiple
regression analysis of the factors affecting thedose parameters for the eye lens. There was asignificant correlation between the lens dose
and the location of the lesions. Besides, the coexistence of organs at risk significantly affected
the lens dose. As for the V0.5, there were no
significant correlated factors.
Figure 2 illustrates the representative casethat the lens dose was affected by the existence of the other organ at risk. This 48-year-

old man had a left cavernous sinus meningioma. In the original treatment planning,
we regarded the optic nerve as the organ at
risk 7) and produced the dose plan without
concern about radiation exposure to the eyelens. Peripheral dose for this lesion was 9 Gy.
The isodose line for 0.5 Gy was unexpectedly
expanded toward the right eye lens despite
the lesion was on the left side. The maximum
doses to the lens were 0.7 Gy in the right and
0.6 Gy in the left, respectively. The dose to theright eye lens which is the contralateral side ofthe lesion was greater than the left.

Table 3 Multiple regression analysis regarding thefactors affecting the lens dose

Fig.1 Frequency distribution of the maximum lensdose.
In 13 cases（23%）, the maximum lens dose reached 0.5
Gy, the ICRP threshold dose for cataract.

aFactorP value
Max dose Mean dose

V0.5

Lesion location(anterior vs. mid)

<0.05

<0.05

0.236

Lesion location(anterior vs. posterior)

<0.05

<0.05

0.377

Lesion location(ipsilateral vs. contralateral)

0.218

0.268

0.380

Lesion volume

0.642

0.438

0.063

Peripheral dose

0.205

0.648

0.075

No. of shots

0.536

0.885

0.448

Other at-risk organ

<0.05

<0.05

0.232

b

Fig.2 Unexpected expansion of the dose distribution.
a）This 48-year-old man had a left cavernous meningioma（arrow ）. We regarded the optic nerve as the organ at risk（arrowhead ）and produced the dose plan.
b）The lesion was irradiated with 9 Gy of peripheral dose. The isodose line for 0.5 Gy was expanded toward
the right lens despite lesion was on the left side. The maximum dose to the right lens was 0.7 Gy, greaterthan the left lens.

Arts and Sciences ◆ 35

3-2 Optimization of the treatment plan
Figure 3 demonstrates the comparison of the

maximum lens dose between before and after
modification. The dose to the eye lens was
significantly reduced in the modified plans.
(P <0.05). Further, the radiation exposure to theeye lens were less than 0.5 Gy in the modified
plans for all of the cases. The comparison of
the D95 is shown in Fig.4. There was no significant difference in the D95. Figure 5 shows
the comparison of the irradiation time. The irradiation time was prolonged by 11.6 min on
average in the modified plans (P <0.05).
Figure 6 illustrates the representative casethat a reduction in the dose to the eye lenscould be achieved by modifying the treatment

Fig.3 Comparison of the maximum dose to the lens.
The maximum lens dose was significantly reduced in themodified plans on which the eye lens was regarded as theorgan at risk. Radiation exposure to the lens were less than
0.5 Gy in all of the plans after modification. *P<0.05

Fig.4 Comparison of the dose covering 95% of
the lesion volume（D95）.
There was no difference in the D95. NS not significant.

36 ◆ Journal of JART English edition 2020

plan. This 62-year-old woman had a meningioma in the olfactory groove. In the originalplan, both eye lenses were covered with the
0.5 Gy isodose line. The maximum lens doses
were 0.7 Gy in the right and 0.9 Gy in the left,
respectively. On the other hand, 0.5 Gy isodose line was away from both eye lenses when
the dose distribution was modified with taking the radiation exposure to the eye lens into
account. As a result, the maximum lens doses
were reduced to 0.4 Gy.

4. Discussion
The fact of the radiation exposure to the eyelens during stereotactic radiosurgery remains
to be clarified although ICRP published thethreshold dose for cataract as 0.5 Gy. Eye lensdoes not seem to be dealt with as organ at
risk for adverse effect at low radiation dose intreatment planning for GKS. To the best of ourknowledge, the present study is the first reportfocusing on this important issue. Our data indicates 23% of cases were exposed beyond the
ICRP threshold dose in GKS for patients withmeningioma (Fig.1). In multiple regression
analysis of the factors affecting the lens dose,the location of the lesions and co-existence oforgans at risk were significant correlated factors (Table 3). While the former seems to bereasonable because the lesions are close to theFig.5 Comparison of the irradiation time.
The irradiation time was prolonged by 11.6 min on average in the modified plans. *P<0.05the original work
Optimization of radiation exposure to the eye lens in stereotactic radiosurgerybac

Fig.6 Dose reduction in the eye lens.
a）This 62-year-old woman had a meningioma in the olfactory groove.
b）In the original plan, both eye lenses were covered with the 0.5 Gy isodose line. The maximum lens doses were 0.7
Gy in right and 0.9 Gy in left, respectively.
c）In the modified plan, the 0.5 Gy isodose line was away from both eye lenses（arrows ）. The maximum lens doses
were reduced to 0.4 Gy.

eye lens, the latter is a new finding. Carefulattention might be necessary to the increase in
the dose to the eye lens due to unexpected expansion of dose distribution when producing
treatment plan with other organs at risk (Fig.2).
In the cases that the lens dose reaches the
ICRP threshold dose, ophthalmological followup may be recommended to check for cataract
induced by stereotactic radiosurgery.
It is possible to distinguish between radiation
related cataract and senile cataract 9). Posterior
subcapsular cataract that occurs at back of thelens is typical type of radiation related cataract.
Young patients, 40s or less in particular, who
undergoing GKS for benign lesions should beobserved as long as possible since previous
studies indicate radiation related cataract was
detected in decades after irradiation 9, 10).
To produce appropriate dose distribution forthe cases which exceeded the ICRP thresholddose level for cataract, we regarded the eyelens as organ at risk and modified the originalplan. As a result, we could reduce the lensdose to less than 0.5 Gy without making any
difference in D95 (Fig.3, 4). Meanwhile, the irradiation time was prolonged by 11.6 min on
average in the modified plans (Fig.5). In thisregard, the gamma knife model at our hospital,
Perfexion is fully robotized and both the radiation beam configuration and the couch positional coordinate setting are automated, whichmakes patient hospitable and mitigates theworkload of the operator 11). Additionally, forpatients which are considered to achieve longterm survival it is required not to raise the levelof occurrence of radiation-induced complications in the rest of their life. Thus, the prolongation of irradiation time was short enough toaccept clinically although there was a trade-off
between a conformal dose plan and irradiation
time. Our effort to optimize radiation exposure
to the eye lens is meaningful in GKS.
The present study has several limitations.
First, this is a single institutional study. Next,
relatively small number of subjects were enrolled in this study. Third, we did not take into
account the movement of the eye ball during
the irradiation when calculating dose to theeye lens. The internal error due to lens motion
should be defined in GKS to make dose evaluation more rationally. Finally, in our experience, there are no patients who is diagnosed
with radiation related cataract. To addressthese issues, a long-term observational study
Arts and Sciences ◆ 37

with a larger number of subjects is necessary in
the future. We believe that the treatment planning with consideration for radiation exposure
to the eye lens is a way to advance GKS as
minimally invasive treatment. We hope thatthe relationship between radiation exposure
to the eye lens in stereotactic radiosurgery andthe occurrence of cataract will be elucidated as
further research in this field progresses.

References
1） Lunsford LD, et al.: Stereotactic radiosurgery of thebrain using the first United States 201 cobalt-60
source gamma knife. Neurosurgery, 24, 151-9, 1989.
2） Ove R, et al.: Preservation of visual fields after perisellar gamma-knife radiosurgery. Int J Cancer, 90,
343-50, 2000.
3） Gondi V, et al.: Why avoid the hippocampus? A comprehensive review. Radiother Oncol, 97, 370-6, 2010.
4） Maruyama K, et al.: Optic radiation tractography integrated into simulated treatment planning for Gamma
Knife surgery. J Neurosurg, 107, 721-6, 2007.
5） Kawasaki K, et al.: Quantification of the radiation doseto the pyramidal tract using tractography in treatment
planning for stereotactic radiosurgery. Radiol Phys
Technol, 10, 507-14, 2017.
6） Stewart FA, et al.: ICRP Publication 118: ICRP statement on tissue reactions and early and late effectsof radiation in normal tissues and organs-threshold

38 ◆ Journal of JART English edition 2020

5. Conclusions
In 23% of patients who underwent GKS, theeye lenses were exposed beyond the ICRP
threshold dose for cataract. We demonstrated
that the treatment plan could be modified inorder to reduce the eye lens exposure below
the threshold level with clinically acceptable
D95 and irradiation time.
We presented this study at the 20th International Society of Radiographers and Radiological Technologists held in Port of Spain, Trinidad and Tobago in April 2018.

doses for tissue reactions in a radiation protection
context. Ann ICRP, 41, 1-322, 2012.
7） Mayo C, et al.: Radiation dose-volume effects of optic
nerves and chiasm. Int J Radiat Oncol Biol Phys, 76(3 Suppl), S28-35, 2010.
8） Kanda Y: Investigation of the freely available easy-touse software 'EZR' for medical statistics. Bone Marrow Transplant, 48, 452-8, 2013.
9） Minamoto A, et al.: Cataract in atomic bomb survivors. Int J Radiat Biol, 80, 339-45, 2004.
10）George R. Merriam, Jr. : A Clinical Study of Radiation
Cataracts. Trans Am Ophthalmol Soc, 54, 611-53,
1956.
11）Régis J, et al.: Radiosurgery with the worldʼs first fully
robotized Leksell Gamma Knife Perfexion in clinicaluse: a 200-patient prospective, randomized, controlled comparison with the Gamma Knife 4C. Neurosurgery, 64, 346-55 (discussion 355-6), 2009.

Arts and Sciences
note

Received December 25, 2017 ; accepted November 30, 2018

The optimal scanning method for three-dimensional T1-weighted black-blood turbo spin-echo
MRI in the aortic arch
Kenichi Nakagawa1）, Masanori Kinosada（medical doctor）2）, Takashi Tabuchi3）,
Noriyoshi Morimoto1）, Sachi Fukushima1）, Takashi Ogasahara1）, Masayuki Kumashiro1）1）Department of Radiological Technology, Kurashiki Central Hospital2）Department of Neurosurgery, Kurashiki Central Hospital3）Department of Medical Technology, Kurashiki Central Hospital

Note: This paper is secondary publication, the first paper was published in the JART, vol. 66 no. 798: 29-33, 2019.
Key words: aortic arch, black blood, plaque, aortogenic embolism, TEE【Abstract】

Aortic arch plaques visualized using transesophageal echocardiography (TEE) are at risk for brain embolism.
However, TEE is not suitable for all patients. Therefore, we focused on scan of MRI with T1-weighted (T1w) black blood
turbo spin-echo (TSE) imaging. This study aimed to clarify the optimal scanning method for 3D T1w black-blood TSE
imaging in the aortic arch. Five healthy volunteers (mean age, 33.8 years; range, 25.0 to 57.0 years) participated in thisstudy. We obtained Institutional Review Board approval and the informed consent of all subjects. All experiments wereacquired by volume isotropic TSE acquisition (VISTA) with anti-DRIVE using a 1.5-T magnetic resonance scanner. The
study protocol was divided on the basis of two aims: 1) To evaluate the combinations of six patterns of phase direction
with and without electrocardiography (ECG) and navigator echo, and 2) to compare the ECG during systole anddiastole to determine the optimal trigger timing. We determined that the combination of phase direction foot-head (FH),
ECG, and navigator echo was the best scanning method. Furthermore, the optimal trigger timing was during diastole,
which showed lesser movement of the vessel wall than during systole. Our results suggest that 3D T1W BB-TSE with
anti-DRIVE using the diastolic trigger timing by ECG-gating and navigator echo respiratory gating in the aortic arch canprovide beneficial information for clinical practice.

1. Introduction
Complex atherosclerotic plaques include irregular surface plaques, ulcerated plaques, andmobile plaques 1), 2). Complex plaques that are
observed in the aortic arch on transesophageal
echocardiography (TEE) are at high risk for
aortogenic brain embolism 3)-8). However, TEE,
which is associated with a number of complications and contraindications, is not suitable
for all patients 9).
However, in the examination of carotid
plaques, magnetic resonance imaging (MRI)
can be used for the diagnosis of plaque components based on MR contrast 10), 11). Unstable
carotid plaques are characterized by a fibrouscap, atheroma, and intraplaque hemorrhage.
In addition, high-intensity plaques on T 1weighted black blood (T1W BB) MRI are con-sidered a useful finding in assessing unstableplaques 12)-14).
Therefore, we focused on the black blood
image of MRI as an adjunct diagnostic modality
for complex plaques of the aortic arch that are
difficult to observe owing to multiple artifacts.
To address these problems, we devised a scanning methodology using three-dimensional
T1-weighted black-blood turbo spin-echo (3DT1W BB-TSE) MRI in the aortic arch. The aim of
this study was to clarify the optimal scanning
method for 3D T1W BB-TSE.

2. Materials and Methods
2.1 Patients

Five healthy volunteers (mean age, 33.8
years; range, 25.0 to 57.0) participated in thisstudy. We obtained Institutional Review Board
Arts and Sciences ◆ 39

approval and informed consent from all participants.
2.2 MR imaging protocol

All scans were performed on a 1.5-Tesla MR
scanner (Ingenia R5-2; Philips Healthcare, Best,The Netherlands) using a 15-channel ds Torso coil as the receiver. All experiments wereacquired by volume isotropic TSE acquisition(VISTA) with anti-driven-equilibrium postpulse (anti-DRIVE) 15), 16). The parameters for
VISTA with anti-DRIVE were as follows: repetition time (TR), 1 beat; echo time (TE), 24
ms; field of view (FOV), 260*260*70 mm; acquisition matrix, 1.1*1.1*4 mm; reconstruction
matrix, 0.55*0.55*2 mm; refocusing flip angle,
30°; TSE factor, 25; start up echo, 4; number ofsignals averaged (NSA), 1. The fat saturation
pulse used spectral attenuated inversion recovery (SPAIR).
2.3 Study protocol and analysis

We obtained 3D T1W BB-TSE images in volunteers who were asked to maintain a natural
breathing style while undergoing oblique sagittal scans of the aortic arch. The study protocol
consisted of two processes: first, to evaluate
the combination of six patterns for phase direction anterior-posterior or foot-head (APor FH), with and without electrocardiogram-

gating (ECG-gating) and navigator echo; andthen, to compare ECG-gating during systoleand diastole to determine the optimal trigger
timing.
Two radiological technologists had experience, more than 5 years in MRI division, andwere involved in visually ranking of motion
artifacts for six image patterns of phase direction. The results of the visual evaluation wereconverted into normal scores, and analysis by
the least significant difference (LSD) method
was performed on this result, and significant
differences in ranking were examined 17). The
P-value for significant difference was definedas P<0.05.

3. Results
Figure 1 shows the results of a visual evalu-

ation performed using the normalized-rank
method and the images obtained using six
patterns of phase direction (AP or FH), withand without ECG-gating and navigator echo. A
significant difference between ECG+navigatorFH and ECG+navigator-AP suggested that FH
improved the motion artifacts (LSD, P<0.05).
Moreover, differences of image qualities between ECG+navigator+FH and ECG+navigatorFH, or ECG+navigator+AP and ECG+navigatorAP indicated usefulness of navigator echo.

Fig.1 The anterior-posterior: AP (top row) and foot-head: FH (bottom row) phase direction. A comparison of three-dimensional T1-weighted black-blood turbo spin-echo images obtained from the electrocardiography (ECG)- navigator-,
ECG+ navigator-, and ECG+ navigator+ scans, respectively, are shown. Also shown are the results of the visualevaluation evaluated using the normalized-rank method.

40 ◆ Journal of JART English edition 2020

note
The optimal scanning method for three-dimensional T1-weighted black-blood turbo spin-echo MRI in the aortic arch

Fig.2 Comparison of the systolic images and the diastolic images obtainedusing navigator echo. The open arrow shows the movement of thevessel wall, and the closed arrow shows the black blood effect.

Furthermore, ECG-gating also improved the
motion artifacts between ECG+navigator-FH
and ECG-navigator-FH.
Further, Figure 2 shows the images obtainedusing ECG-gating on systole and diastole withnavigator echo. ECG-gating on systole had aprofound effect on both BB and motion artifacts of the ascending aorta. In contrast, low
extent of flow-related signal loss was observedon ECG-gating at diastole, but motion artifactsof the vessel walls were decreased. The images
from the four remaining healthy volunteers
demonstrated the same results.

4. Discussion
4.1 The effect of respiration

In this study, the use of navigator echo improved the image quality by reducing the motion artifacts associated with respiration (Figure1). Navigator echo measured the diaphragm
position during free breathing, and this information allowed for triggering on the defined
window within the respiratory cycle. Ample
studies have demonstrated the utility of navigator echo 18). However, it is necessary to set standards high to reduce the effect of respiration,
thereby scan time is extended. In addition,
oblique sagittal scanning could be problematicin image qualities because of motion artifact
in the liver and the thorax. The AP and FH
phase directions would reduce the motion ar-

tifact by the liver and the thorax, respectively.
This study demonstrated that the FH phasedirection resulted in improvement of the image quality. Setting the navigator echo aroundthe diaphragm also improved the precision of
the image of the liver without motion artifactof the liver. However, we assume that the accuracy of movement correction of the thorax
was reduced due to the navigator echo directlycollection at a site distant from the thorax. In
other words, modifications to the setup thenavigator echo would be required to decrease
motion artifact of the thorax on imaging of theaortic arch.
4.2 The effect of ECG-gating

In this study, we were able to obtain good
image qualities by reducing the motion artifacts associated with pulsations with ECGgating. Furthermore, significant results wereobtained for visual evaluation performed using
the normalized-rank method as in Figure 1.
The aortic arch generally shows severe artifacts owing to pulsations of the aortic arch 19).
However, the present results indicated that
ECG-gating reduced the motion artifact of thepulsations because of synchronization with the
cardiac phase. We compared the effect of setting the cardiac trigger timing to either systoleor diastole. Figure 2 shows the relationshipbetween the BB effect and the motion artifactof the ascending aorta. For the patients with
Arts and Sciences ◆ 41

reduced blood flow, the timing of ECG-gating
at systole was better than diastole because of
the flow void effect. In other words, regarding the BB effect, the systole is more advantageous. However, several studies have reported
that mobile or ulcerated plaques and large
atheromatous aortic plaques of over 4 mm inthickness on TEE can cause aortgenic brain
embolism 4)- 6). Therefore, to diagnose complex
plaques in the aortic arch, a reliable method formeasuring the thickness of the aortic plaques
was important. Thus, the reduction of motion
artifacts should be given priority over the BB
effect in diagnosis of complex plaques in theaortic arch. The images in Figure 2 suggest that
ECG-gating during diastole was more accurate.
4.3 Clinical images and Limitations
Figure 3 shows the clinical images of theaortic arch. We were able to obtain the highintensity plaques of the aortic arch. Furthermore, 3D T1W BB-TSE with anti-DRIVE shows
more clearly existences of multiple vulnerable

plaques on the vessel wall comparing with
contrast-enhanced computed tomography.
However, for the patient with cardiac hypofunction or a reduced blood flow, the diastolic
image might decrease the contrast of complex
plaques and the BB effect, increasing possibility of incorrect diagnosis. In addition, themeasurement of thickness of vessel wall in
the patient with arrhythmia using this method
would not shows high accuracy of images.

5. Conclusion
Our results suggest that 3D T1W BB-TSE with
anti-driven-equilibrium post-pulse in the aorticarch could provide beneficial information forclinical practice when using the diastolic trigger timing with ECG-gating and navigator echo
respiratory gating.

Acknowledgements
We sincerely thank the RTs in the Department of Radiological Technology, Kurashiki
Central Hospital.
Conflict of interest

The authors declare that they have no conflict of interest.

References

Fig.3 Clinical images of 3D T1W black blood-TSE with
anti-driven-equilibrium post-pulse ( 3D T1W BBTSE with anti-DRIVE ) in the aortic arch whenusing the diastolic trigger timing with ECG-gating
and navigator echo respiratory gating. On 3D
T1W BB-TSE with anti-DRIVE (a), the high intensity plaque of brachiocephalic artery is seen. A
comparison between 3D T1W BB-TSE with antiDRIVE and contrast-enhanced computed tomography (CECT) (b), 3D T1W BB-TSE with antiDRIVE shows multiple vulnerable plaques on thevessel wall more clearly than CECT.

42 ◆ Journal of JART English edition 2020

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13）Nakamura M, et al.: Volumetric black blood angiography by low refocusing flip angle 3D turbo spin echo in

the intracranial vertebrobasilar artery. JJMRM, 31 (4),187-197, 2011.
14）Nakagawa K, et al.: Optimization of black blood cinefor mobile plaque. Japanese Journal of RadiologicalTechnology, 69 (11), 1274-1280, 2013.
15) Ogawa M, et al.: Fundamental study of three-dimensional fast spin-echo imaging with spoiled equilibrium
pulse. Japanese Journal of Radiological Technology,
73 (1), 26-32, 2017.
16）Yoneyama M, et al.: Improvement of T1 Contrast in
Whole-brain Black-blood Imaging using Motion-sensitized Driven-equilibrium Prepared 3D Turbo Spin Echo
(3D MSDE-TSE). Magn Reson Med Sci, 13 (1), 61-65,
2014.
17）Nakamae M.: Study of the Reliability of Visual Evaluation by the Ranking Method: Analysis of Ordinal Scaleand Psychological Scaling Using the Normalized-rank
Approach. Japanese Journal of Radiological Technology, 56 (5), 725-730, 2000.
18）Wang Y, et al.: Navigator-echo-based real-time respiratory gating and trigger for reduction of respiration
effects in three-dimensional coronary MR angiography. Radiology, 198 (1), 55-60,1996.
19）Jonathan SL, et al.: Three-dimensional time-of-flight
MR Angiography; Applications in the abdomen andthorax. Radiology, 179, 261-264, 1991.

Arts and Sciences ◆ 43

Arts and Sciences
the original work

Received July 17, 2018; accepted January 25, 2019

Evaluation of fat-suppression effects on ankle
magnetic resonance imaging: Trial of improvement of image quality by changing the posture
Hiromi Usui 1）, Yuichi Nakai 2）, Chikara Noda2），3）, Hisaya Sato1），3）, Kyoichi Kato3），4）
1）Department of Radiological Technology, Showa University Hospital2）Department of Radiological Technology, Showa University Northern Yokohama Hospital3）Showa University Graduate School of Health Science4）Department of Unification Radiological Technology, Showa University

Note: This paper is secondary publication, the first paper was published in the JART, vol. 66 no. 799: 26-31, 2019.
Key words: Fat suppression, Positioning method, Ankle【Abstract】

Fat-suppression images are useful for imaging diagnosis. The Chemical Shift Selective saturation is susceptible tomagnetic field inhomogeneities and can often be insufficient in usefulness for the feet and neck regions, which areparticularly irregular in shape. The fat-suppression effect can be improved by placing a Sat Pad to correct the shapeirregularities. However, there are many images of sprains and fractures in the feet, and placing a heavy Sat Pad will
exert pressure on the injured part, which may interfere with healing. The aims of this study were to compare the useof Sat Pad and the method of changing the angle of feet devised in this study and to evaluate the improvement effectof fat-saturation defects.

Introduction
The most frequent form of sports injury is a
sprained ankle 1). A sprain refers to damage tothe complex ligaments or tendons of the ankle.
Assessing a sprain requires differentiating itfrom fifth metatarsal fractures or dislocations oftendons of the peroneus muscles, which show
similar symptoms as a sprain 1). Major factors
contributing to a sprained ankle include osteochondritis dissecans, an arthrophyte, subtalar
joints, and midfoot sprains, which should beassessed. Damage to the complex tendons andligaments and early-stage osteochondritis dissecans often cannot be diagnosed using X-ray
imaging alone. As the ankle is composed ofmuscles, fat, bone marrow, and other soft tissues, diagnostic magnetic resonance imaging(MRI), which offers excellent tissue contrast
and qualitative diagnosis, is useful 2). Fat suppression is performed on images to identify lesions in the adipose tissue or fatty bone mar-

44 ◆ Journal of JART English edition 2020

row to ascertain the spread of lesions and to
mitigate chemical-shift artifacts 3). Methods offat suppression include frequency subtraction,phase subtraction, and T1 relaxation time subtraction. However, a form of frequency-selective fat suppression imaging called Chemical
Shift Selective (CHESS) saturation, which canbe included for all sequences, is often used 2).
This method applies the differences in resonance frequencies between water and fat toselectively saturate fat signals, thus enablingcorrect suppression of the fat component of thefrequency band 4). T1-weighted images (T1WIs)
that are contrast-enhanced with the CHESS
technique are also useful for suppressing thebone marrow fat in inflammatory lesions inside
the bone or contacting bone 5). However, it iseasily affected by an uneven magnetic field,
making the fat suppression effects also likely to
be uneven. In particular, because 3-T MRI devices have greater magnetization vectors compared to low-magnetic-field devices, the un-the original work
Evaluation of fat-suppression eﬀects on ankle magnetic resonance imaging: Trial of improvement of image quality by changing the postureeven magnetostatic field and uneven local
magnetic field tend to cause uneven fat suppression effects in the foot 6) (Fig.1).
Disturbances to the local magnetostatic field
during MRI can be reduced by placing a Sat
Pad 7) (Sat Pad, West Chester, PA), which is amagnetic resonance device with a magnetic
susceptibility close to that of the human body,in the periphery of the subject in order to reduce magnetic susceptibility artifacts caused by
the uneven local magnetic field resulting fromdifferences in the magnetic susceptibility between the subject and the surrounding air.
Moriya et al. reported 8, 9) that arranging a tailormade Sat Pad on the neck to compensate forirregularly shaped body parts yields improved
fat suppression compared to commerciallyavailable Sat Pads. Applying the tailor-madepad to the ankle, which is also irregularly
shaped, is expected to make magnetic susceptibility more uniform. In clinical settings, however, adding weight to an unstable sprained
ankle because of ligament damage or fracture
increases the risk of delayed healing or worsening of the patientʼs condition 10). Therefore, it
is important to investigate factors that can improve fat suppression effects with little load on
the patient. Because the arrangement of theankle relative to the magnetostatic field isthought to disturb the magnetic field, it would
be useful to investigate methods of positioning

the ankle so as to prevent disturbing the magnetic susceptibility. Therefore, we comparedpatient positions using a tailor-made pad,which is believed to improve fat suppression,and report the useful positions for improving
fat suppression (Fig.1).

1. Subjects and equipment used
The device used was the MAGNETOM Trio,
A Tim 3T (Siemens, Erlangen, Germany) with ahead-matrix oil (12 channels) for the head as
the receiving coil. A tailor-made phantom(Fig.2) was created by molding agarose (resembling the parenchymal tissue) into the L
shape, imitating the ankle, and solidifying salad oil (resembling adipose tissue) around it.
For the tailor-made pad, rice was placed in aplastic bag.
The subjects were ten healthy volunteers,
including seven men and three women, aged
24-35 years, with a mean age of 28 years, whowere approved by our hospitalʼs ethics committee and consented to the present study(Fig.2).

Fig.2 Appearance and composition of the tailormade phantom

2. Imaging conditions

Fig.1 Image of poor fat suppression in the footby Chemical Shift Selective

T1WIs were obtained with fat suppression
under high-speed spin echo (SE). The imaging
parameters were: repetition time (TR), 600 ms;
echo time (TE), 5.8 ms; bandwidth, 454 Hz/
Arts and Sciences ◆ 45

pixel; turbo factor, 3; slice thickness, 5.0 mm;
matrix size, 166 × 256; field of view, 190 mm;
15 sagittal slices. The fat suppression method
used was the CHESS technique.

the visual assessment were also compared withthe absence of the tailor-made pad (Figs.4, 5).

3. Methods
Visual assessment was performed by fiveclinical radiologists with at least 5 years of experience using MRI. The method of assessment
was to divide the foot into seven segments andvisually assess each segment, rating them asfollows: 2 points for evenly applied fat-suppression effects, 1 point for poor fat suppression of less than 50% of the segment, and 0
point for poor fat suppression in 50% or moreof the segment (Fig.3).

Fig.4 Conventional foot positioning on magnetic resonance imaging: knee extended, sole flexed

Fig.3 Segmenting of the phantom and foot in thevisual assessment

Fig.5 Combinations of pad placement methods

3-1 Optimal arrangement of the tailor-made pad

3-2 Considerations for the optimal position

Our standard positioning for ankle MRI is theknee joint extended and the ankle dorsiflexed
at 90°(Fig.4). An L-shaped phantom was created in this position. The tailor-made pad wasarranged on this phantom, and T1WIs were acquired using CHESS to study the changes infat-suppression effects. There was a total of 8
positions in which the tailor-made pad wasplaced: no pad; the pad only at the dorsum,
sole, or heel; and pads in a combination oflocations (Fig.5).
The resulting images were assessed visuallyfor the optimal arrangement of the tailor-madepad. The resonance frequencies with the optimal tailor-made pad placement obtained from

Sagittal T1WIs of the phantom placed at different angles were acquired using CHESS to
study the changes in fat-suppression effects.
The angle of arrangement of the phantom waschanged to have the angle formed by the bed
and lower leg move 5°at a time from 0°to
45°(Fig.6).
The resulting images were visually assessedto find the optimal angle for the angle formedby the bed and lower leg.
The resonance frequency captured with the
optimal angle as obtained from the visual assessment was compared with that obtainedwith conventional positioning (Fig.6).

46 ◆ Journal of JART English edition 2020

the original work
Evaluation of fat-suppression eﬀects on ankle magnetic resonance imaging: Trial of improvement of image quality by changing the posture

4. Results
4-1 Optimal arrangement of the tailor-made pad

Where the tailor-made pad was not used, fatsuppression effects of the dorsum-, sole-, andtoe tip-like portions of the tailor-made phantom were poor (Table 1). When the tailor-madepad covered the dorsum, which is irregularly
shaped, the visual assessment had a total scoreof 50 points, showing the greatest improveFig.6 Changes in the angle formed by the lower
leg and bed

Table 1 Sat Pad placement methods and magnetic
resonance images

3-3 Comparison of phantom images with tailor-made pad use and altered positioning
Images were visually assessed to compare
differences between the tailor-made pad andaltered positions.
3-4 Comparison of images from healthy volunteers

The ten volunteers were imaged with optimal
tailor-made pad placement and optimal positioning as obtained from the results and visually assessed.
3-5 Changes in the center frequency with modified positioning

To investigate how changing the angle of thefoot affects fat suppression, the set range ofshimming during imaging was changed, andthe center frequency at the time was measured.
There were five set ranges of shimming: whole,foot, lower leg, from the foot to the heel, andfrom the lower leg to the heel (Fig.7).
Fig.8 Visual assessment based on pad placement

whole

plantarleg

plantar / ankle

leg / ankle

Fig.7 Seetting the range of shimming during center frequency measurement
Arts and Sciences ◆ 47

ment in fat-suppression effects (Fig.8).
For the resonance frequency without the tailor-made pad, the water signal was separated
into two halves. However, with optimal placement of the tailor-made pad as obtained fromvisual assessment, there was only one water
signal, and the water and fat signals were separated (Figs.8, 9; Table 1).

formed by the lower leg and bed was between, there was one water signal, and35°and 45°
the water and fat signals were separated(Fig.10; Table 2).

Fig.10 Comparison of images and resonance frequencies with changes in the angle formedby the lower leg and bed

Fig.9 Comparison of captured images and resonance frequencies (with pad placement)

4-3 Comparison of phantom images with tailor-made pad use and with altered positioning

4-2 Considerations for the optimal position

Fat-suppression effects were poor while imaging in the conventional position for the dorsum, sole, and toe tips of the phantom, andimproved when the angle formed by the lower
leg and the bed was 35°to 45°(Table 2).
With conventional positioning, the water signal of the resonance frequency was separated
into two halves. However, when the angle

Overall fat-suppression effects on the footwere uniform with the tailor-made pad and thepositioning angle was 45°(Fig.11).

Table 2 Comparison of images with changes in
the foot angle

Fig.11 Image comparison with pad use and changes
in the angle formed by the lower leg and bed

4-4 Comparison of images of healthy volunteers

Among the healthy volunteers, when the positioning was changed, the visual assessmentscore was a total of 33 points, which was thehighest score (Fig.12). Fat suppression was
uniformly applied to the foot as a whole when48 ◆ Journal of JART English edition 2020

the original work
Evaluation of fat-suppression eﬀects on ankle magnetic resonance imaging: Trial of improvement of image quality by changing the posture

the positioning changed, but when the tailormade pad was placed, there were poor fat suppression effects applied from the top of thefoot to the sole (Fig.13).

Fig.14 Trends in the center frequency withchanges in the shimming range

Fig.12 Visual assessment of volunteer images
without pad, with pad, and with changes in
the angle formed by the lower leg and bed

Fig.13 Image comparison with pad, without pad,and with changes to the angle formed by
the lower leg and bed

4-5 Changes in the center frequency withmodified positioning
From 35°to 45°, when the fat-suppression effects had improved, the results showed lessvariance in the center frequency from the rangeof shimming (Fig.14).

5. Discussion
As the foot has an irregular shape, which results in poor fat suppression when placed in amagnetostatic field, correcting the shape of theankle with a tailor-made pad improves fat-suppression effects. The tailor-made pad achieved
a uniform magnetic field near the phantom,
suggesting that the frequency distributions ofwater and fat changed, producing a more uniform fat-suppressed image. However, when
the tailor-made pad was placed on healthy volunteers, fat-suppression effects were inadequate. This may be because the foot and tailormade pad have different shapes, causing aseparating layer of air to remain between them,rendering the magnetic susceptibility non-uniform.
We had thought that changing the patientʼs
position with the tailor-made pad may improve
the fat-suppression effects. The fat-suppression
effects improved when the angle formed by. This imthe lower leg and bed was 35°to 45°
plies that placing the foot parallel to the magnetostatic field improved the uniformity of themagnetic field.
Changing the position is believed to havestabilized the center frequency of the foot andimprove the fat-suppression effects.
The method of changing the position is may
have yielded a consistent improvement, regardless of individual differences in the shapeof the foot, as with the placement of the tailormade pad, because imaging was performed
with overall changes to the foot.

Arts and Sciences ◆ 49

6. Conclusion
In ankle MRI using the CHESS technique, thenon-uniform magnetic field has lowered thequality of fat-suppression effects, but placing a
recently recommended tailor-made pad 7) on
the dorsum brought about improvement in fatsuppression effects. However, when there wasa separating layer of air between the foot andthe tailor-made pad, the uniformity of the magnetic field was compromised, resulting in inadequate fat-suppression effects. Introducing anangle of 35°to 45°between the lower leg andthe bed in the present study yielded better fatsuppression effects compared to using a tailormade pad, allowing for a more uniform magnetic field due to the placement of the footpointing directly at the magnetostatic field.
This suggests that changing the patientʼs position could enable consistent fat-suppression
effects in the clinical practice, regardless of the
shape of the foot and without applying theweight of a tailor-made pad to an injured foot.

Acknowledgments
We are grateful to the engineers in the radiation department of Showa University Hospitalfor their valuable opinions as well as their cooperation in image assessment, data collection,and more.
The Abstract of this paper was published at
the autumn academic conference of the Japanese Society of Radiological Technology (October 2012, Tokyo) and at the 99th North American conference (December 2013, Chicago).

50 ◆ Journal of JART English edition 2020

References
1） Kuzuhara, K. Shimamoto, H.: Management of Ankle
Sprains. Journal of Aichi Toho University 2006; 35(2):1-12 (in Japanese).
2） Suzuki, N.: Optimization and Clinical Application of Fat
Suppression MRI Using CHESS and STIR. JapaneseSociety of Radiological Technology 25th autumn academic conference. 1997; 53(9): 1418 (in Japanese).
3） Obinata, K. Ozawa, K. Takahashi, Y. et al.: Fat suppression. Hitachi Medical Corporation MEDIX 2009;
50: 41-48 (in Japanese).
4） Kasai, T. Doi, T.: MR Imaging Technology, 2nd revised
edition. Ohmsha Ltd. 2010; 288-289.
5） Kasai, T. Ogawa, N.: Medical Imaging Equipment, 1stedition. Ohmsha Ltd. 2008; 288-289.
6） Kanamori, I. Fujino, A. Niwa, M. et al.: MR practice:from basics to interpretation. 1st edition. Iryo Kagaku.
2011; 134 (in Japanese).
7） Miyagawa, T. Yasui, K.: Attempting to improve image
quality in cervical MRI and cervical angiography: Clinical evaluation using Sat Pad. INNERVISION 1994;
9(11): 77-83 (in Japanese).
8） Moriya, S. Miki, Y. Yokobayashi, T. et al.: Rice pads:
Novel devices for homogeneous fat suppression in
the knee. Acta Radiol 2010; 51(2): 175-178.
9） Honda, T. Arai, K. Nishimura, F. et al.: The rice Sat
Pad is useful in neck MRI. Tokyo Journal of Radiological Technology 2008; 30 (in Japanese).
10）Emergency Medicine, University of Fukui Hospital.
Ankle sprain: “It looks like I sprained my ankle while
playing volleyball”. Therapy 2008; 90(10): 2702-2704(in Japanese).

Arts and Sciences
the original work

Received November 7, 2018 ; accepted January 25, 2019

The effect of body thickness on image quality
using either a semiconductor detector gamma
camera or Anger-type gamma camera when performing a myocardial perfusion SPECT: A Phantom study
Koji Nakaya1），2）, Yoshifumi Nouno2）, Ryota Kaku3）, Hiroe Muto1）, Kanae Matsuura1）,
Ryo Higashide1）, Eisuke Yasuda1）1）Department of Radiological Technology, Faculty of Health Science, Suzuka University of Medical Science2）Department of Radiology, National Cerebral and Cardiovascular Center3）Room of Radiation Technology, Aoyama General Hospital

Note: This paper is secondary publication, the first paper was published in the JART, vol. 66 no. 800: 23-30, 2019.
Key words: myocardial perfusion SPECT, body thickness, semiconductor detector gamma camera【Abstract】

The effect of body thickness on image quality was compared and examined for both semiconductor detector andanger-type gamma cameras using myocardial perfusion SPECT. A 1 cm defect was made in the anterior wall of theheart liver HL type phantom. Then, SPECT scans were acquired when either 0, 2, 4, or 6 cm of fat-equivalent material
was wrapped around the phantom. Using the Plot Profile within ImageJ, we compared the contrast of the phantom
defect with the half width or the visual conspicuity of the SPECT image. As the body thickness increased, the contrast
and visual conspicuity of the phantom defect decreased for the semiconductor detector gamma camera, but thecontrast and visual conspicuity of the phantom defect did not change for the Anger-type gamma camera. The full
width at half maximum of the phantom defect did not change for both devices when the body thickness increased.
Because the semiconductor detector gamma camera has higher resolution and sensitivity than the Anger-type gamma
camera, the image quality depends on body thickness.

1. Introduction
Myocardial perfusion single photon emission computed tomography (MP SPECT; MPS)
is affected by attenuation and scattering fromfat and muscle, especially in obese patients 1).
In addition, patients with thick bodies havea large distance between the site of radioisotope accumulation and the collimator, which
affects the image quality. In recent years, thenumber of facilities where MPS is performed,
not only by conventional Anger-type gamma
cameras (AGC) but also by SPECT devices
equipped with semiconductor detectors (semiconductor detector gamma cameras (SDGC)),
has increased 2). Semiconductor detectors havehigher resolution and sensitivity than scintillator detectors used in conventional AGC. In
addition, the acquisition time is short, and theimage quality is excellent 2 - 6) for SDGC. Furthermore, because the SDGC has high resolution and sensitivity, SPECT imaging can be performed using less radioisotope 7, 8). However,even SDGC image quality is deteriorated byobesity. In this study, we would like to determine which of the two devices, AGC or SDGC,
is more affected by obesity. Therefore, theeffect of body thickness on image quality for
SDGC and AGC was compared using a phantom experiment.

2. Materials and Methods
2-1. Creating a phantom

In this study, a cardiac liver HL phantom(Kyoto Kagaku Co., Ltd., Kyoto, Japan) wasused. A 1 cm defect was created in the anterior wall of the myocardium. Fig.1 shows theArts and Sciences ◆ 51

Fig.1-1 Heart liver phantom

Fig.1-2 Defect part of myocardium phantom

Fig.1 Cardiac liver phantom and defective part of the anterior wallFig.2-1 Image of fat equivalentphantom (2 cm)

Fig.2-2 Image of a myocardium phantom with a body thicknessof 6 cm wrapped with a fat equivalent phantom

Fig.2 Image of body thick myocardium phantom wrapped with fat equivalent phantom and fat
equivalent phantom
Description of Fig.2-1
The image on the left is an image that solidifies the oil contained in the plastic container.
The image on the right is a phantom image from which hardened oil is taken out.

cardiac liver phantom with the missing part of
the anterior wall. A 120 ml aqueous solutionof 99mTc with a radioactivity concentration of
0.123 MBq/mL was enclosed in the myocardium. This concentration is about 2% of the
drug accumulated in the myocardium in 99mTcmethyl isobutyl isonitrile (99mTc-SESTA MIBI)
used clinically 9). Based on this, it was hypothesized that 2% accumulation in the myocardium
occurs 60 minutes after administration of 740
MBq. In this study, the effect of body thickness
was investigated without considering scatteredradiation. Therefore, lungs, mediastinum, andliver were filled with distilled water to eliminate the potential for scattered radiation fromother organs. A fat-equivalent phantom simulating different body thicknesses was preparedby hardening canola oil with an oil hardener.

52 ◆ Journal of JART English edition 2020

Heated oil was added to a plastic container(length 30 cm, width 21 cm, and height 8 cm)
and solidified to create a fat-equivalent phantom simulating a body thickness of 2 cm. Fourlayers of fat-equivalent phantom (length 30
cm, width 21 cm, and height 2 cm) were made.
Different numbers of layers were stacked
and wrapped around the outer periphery ofa cardiac liver HL phantom to create a bodythickness of either 0, 2, 4 or 6 cm. Fig.2 shows
the myocardial phantom wrapped with a fatequivalent phantom with a body thickness of 6cm.
2-2. SPECT acquisition

Different thicknesses of the fat-equivalentphantom, 0, 2, 4, and 6 cm, were wrappedaround the myocardial phantom and SPECT

the original work
The eﬀect of body thickness on image quality using either a semiconductor detector gamma camera or Anger-type gamma camera when performing a myocardial
perfusion SPECT: A Phantom study

Fig.3-1 An image obtained by collecting
myocardial phantom of bodythickness 0 cm with D-SPECT

Fig.3-2 An image obtained by collecting
myocardial phantom of bodythickness 2 cm with Brightview

Fig.3 Image of appearance when phantom is collected in both devices

scanned using both a SDGC and an AGC.
Fig.3 shows the experimental set-up. The
SDGC used a D-SPECT (Spectrum Dynamics,
Caesarea, Israel) with a wide-angle tungsten
collimator (parallel hall) and cadmium-zinctelluride (CZT) semiconductor detectors. An
acquisition time of 4 minutes 5 seconds, whichcorresponded to 1.5 million counts in the left
ventricle (LV counts) when a fat equivalentphantom was not present (0 cm), was used
for all body thicknesses. The energy window
was 140 keV ± 10%, the matrix size was 16 ×64/column, the field of view (FOV) was 160
mm, the magnification was 1x, and the pixel
size was 2.26 mm. The projections were reconstructed using 3D ordered-subset expectation
maximization (OSEM-3D) with 7 iterations and
32 subsets. Attenuation correction and scattercorrection were not used.
The AGC used Brightview (Philips, Amsterdam, the Netherlands) of the two-detector
type. The collimator was placed at 90 °and a
cardiac high-resolution collimator (CHR) wasused. The data was collected in one direction
for 50 seconds (50 sec/step), the rotation angle, and data in the 180 °direction was colwas 6 °lected. The energy window was 140 keV ±10%, the matrix size was 64 × 64, the magnification was 1.85, and the pixel size was 2.26
mm. The projections were reconstructed using
maximum likelihood expectation maximization

method (MLEM method) using 15 subsets and
1 subset. The preprocessing filter used was a
Butterworth filter (order, 10; cut-off frequency,
0.50 cycle/cm). Attenuation correction andscatter correction were not used.
The imaging protocol and reconstruction
conditions for both the SDGC and AGC wereconsistent with those used clinically at the National Cardiovascular Center hospital.
2-3. Defect contrast ratio

A total of three cross sections were extracted:
the slice centered on the defect of the shortaxis SPECT image, and the slices before andafter the defect. A region of interest (ROI)
was drawn using ImageJ (National Institutesof Health, Bethesda, America) for the crosssection centered on the myocardial and thedefect. An accumulation intensity profile curveof pixel value was created from the ROI using
the Plot Profile function in ImageJ. Fig.4 shows
the ROI setting and the accumulation intensity
curve of pixel values created from that ROI.
The contrast ratio was calculated by the following formula (1), with the minimum pixel
value of the defect obtained from the profile
curve as the minimum value and the maximum
pixel value at the of the surrounding myocardial thickness as the maximum value.

Arts and Sciences ◆ 53

Fig.4-1 Setting of ROI

Fig.4-2 Profile curve

Fig.4 How to set Region of Interest (ROI) centered on center part of myocardial and defect part and creation of profile curve
The profile curve in Fig.4-2 is a graph of D-SPECT collected case (thickness is 0 cm).
Max is the pixel value at the center of the myocardium. Min is the pixel value at the center of the defect. Full width at half maximum (FWHM) is the distance (mm) on the horizontal axis at the midpoint
between max and min.

maximum-minimum

Defect contrast ratio = maximum+minimum （1）Pixel value of missing part: minimum
Pixel value at the center of myocardial
thickness: maximum
2-4. Full width at half maximum of the defect

The full width at half maximum (FWHM) was
calculated as the width of the defect portion at
the intermediate value between the pixel valueof the missing portion of the profile curve andthe central pixel value of the myocardial thickness. The FWHM of the defect for the SDGC
and AGC was compared for varying bodythicknesses.
2-5. Visual evaluation of the defectTwelve radiological technologists evaluatedthe defect on SPECT images (short axis, vertical long axis and horizontal long axis) of each
body thickness of both devices. Defects were
evaluated using a 5-point scale: 1 (poor), 2(fair), 3 (average), 4 (good), and 5 (excellent).
The values were averaged and compared foreach body thickness for both devices.

were any statistically significant differences incontrast ratios of the defect at each body thickness, where significance was p<0.05. When significant differences were determined, the posthoc Tukey test was used. The same statisticalanalysis was performed for FWHM and visualevaluation for each body thickness.

3. Results
3-1. Defect contrast ratio
Fig.5 shows the defect contrast ratios foreach body thickness and for both gamma
cameras. The defect contrast ratios (mean ±SD) for body thicknesses of 0, 2, 4, and 6 cm
in D-SPECT were 0.39 ± 0.04, 0.33 ± 0.02, 0.34,
and 0.27 ± 0.01, respectively. The defect contrast ratios for the D-SPECT were significantly
different between 0 cm and 2 cm, 0 cm and4 cm, and 0 cm and 6 cm ( p<0.05). For the
Brightview, the defect contrast ratios for bodythicknesses of 0, 2, 4 and 6 cm were 0.21 ±0.02, 0.23 ± 0.01, 0.22 ± 0.02, and 0.20 ± 0.02,
respectively. However, there were no significant differences in the defect contrast ratios
due to body thickness (n.s.).

2-6. Statistical analysis

One-way analysis of variance (one-way
ANOVA) was used to determine whether there

54 ◆ Journal of JART English edition 2020

3-2. Full width at half maximum of the defectFig.6 shows the FWHM of the defect forthe original work
The eﬀect of body thickness on image quality using either a semiconductor detector gamma camera or Anger-type gamma camera when performing a myocardial
perfusion SPECT: A Phantom study

Fig.5-1 Contrast ratio of D-SPECT

Fig.5-2 Contrast ratio of Brightview

Fig.5 Graph of the result of the contrast ratio of the defect part depending on
the body thickness of both devices
One-way ANOVA was carried out for the significance test of the contrast ratio of the defectin each body thickness.
A significance level was set at p <0.05, and a significant difference was observed between
body thicknesses of D-SPECT ( p <0.05). In order to investigate which body thickness there
is a significant difference, multiple comparison by the Tukey method was carried out.

Fig.6-1 FWHM of D-SPECT

Fig.6-2 FWHM of Brightview

Fig.6 Graph of the result of the full width at half maximum (FWHM) of the defect part depending on the body thickness of both devices
One-way ANOVA was performed for the significant difference test of FWHM of the defectpart due to the difference in body thickness. The significance level was set at p <0.05, andno significant difference was observed between body thicknesses of both devices (n.s.).

varying body thicknesses for both gamma cameras. The FWHM (mean ± SD) of the defects forbody thicknesses of 0, 2, 4, and 6 cm with the
D-SPECT were 16 ± 0.94, 17 ± 0.47, 18 ± 0.47,
and 16, respectively. However, there was no
significant difference in the FWHM of the defect due to body thickness using the D-SPECT(n.s.). The FWHM of the defects with bodythickness of 0, 2, 4 and 6 cm in Brightview
were 16 ± 0.94, 18 ± 0.82, 17 ± 0.82, and 15 ±0.00, respectively. However, there was no significant difference in the FWHM of the defectdue to the body thickness of Brightview (n.s.).
3-3. Visual evaluation of the defectFigs.7 and 8 show the visual evaluation

results and SPECT images of the defect foreach body thickness of both devices. The visual evaluations (mean ± SD) of the defects
with body thickness of 0, 2, 4, and 6 cm in DSPECT were 4.7 ± 0.42, 3.8 ± 0.60, 3.6 ± 0.69,
and 3.2 ± 0.37, respectively. The visual evaluations of the defect at each body thickness
on D-SPECT showed significant differences
Arts and Sciences ◆ 55

Fig.7-1 Visual evaluation of D-SPECT

Fig.7-2 Visual evaluation of Brightview

Fig.7 Graph of visual evaluation results of defect due to body thickness of bothdevices
One-way ANOVA was carried out for the significance test of the visual evaluation each bodythickness.
A significance level was set at p <0.05, and a significant difference was observed between
body thicknesses of D-SPECT (p <0.05). In order to investigate which body thickness there
is a significant difference, multiple comparison by the Tukey method was carried out.

Fig.8-1 SPECT image of D-SPECT

Fig.8-2 SPECT image of Brightview

Fig.8 single photon emission computed tomography (SPECT) image of the defect part due to body thickness of both devices

between 0 cm and 2 cm, 0 cm and 4 cm, and 0
cm and 6 cm ( p<0.05). For Brightview, the visual evaluations of the defects with body thickness of 0, 2, 4, and 6 cm were 4.0 ± 0.67, 3.2± 0.70, 3.4 ± 0.45, and 3.3 ± 0.92, respectively.
However, there were no significant differencesin the visual evaluations of the defect due tothe body thickness for the Brightview (n.s.).

56 ◆ Journal of JART English edition 2020

4. Discussion
The effect of body thickness on image quality of myocardial perfusion SPECT was compared for SDGC and conventional AGC using aphantom experiment.
The defect contrast ratio for D-SPECT gradually decreased with increasing body thickness.
The defect contrast ratio for a body thicknessof 6 cm was significantly lower than for 0 cm

the original work
The eﬀect of body thickness on image quality using either a semiconductor detector gamma camera or Anger-type gamma camera when performing a myocardial
perfusion SPECT: A Phantom study( p<0.05). In addition, the visual evaluation of
defect in D-SPECT decreased with increasing
body thickness, and the visual evaluation of
the defect with body thicknesses of 2, 4, and6 cm were significantly lower than that of 0
cm ( p<0.05). D-SPECTʼs SDGC has high sensitivity and high resolution, so SPECT image
was greatly attenuated and scattered by the fat
equivalent phantom. Therefore, it is assumed
that more attenuation and scatter lead to insufficient counts and deteriorated image quality.
Hence, contrast ratio and visual evaluation
decreased as the body thickness increased. For
the Brightview, SPECT is collected at 50 sec/
step for all body thicknesses. The acquisition
time for 1.5 million LV counts was 4 minutes 5
seconds when the body thickness of D-SPECT
was 0 cm. Therefore, D-SPECT was performed
with this fixed acquisition time for all bodythicknesses. Therefore, as the body thickness
is increased, attenuation and scattering causedby the fat-equivalent phantom leads to an insufficient amount of counts. However, the acquisition of D-SPECT can be terminated either
after a fixed acquisition time or after acquiringa certain amount of LV counts. Using the latter method, image quality can be improvedfor obese patients by increasing the acquisition time. Because the acquisition conditions

Fig.9-1 Positioning image withbody thickness 0 cm

used by both gamma cameras were adopted
from clinical practice, both gamma cameras
do not have the same counts per pixel. Whenacquiring with D-SPECT, the LV is placed
within the dotted line as shown in Fig.9-1.
This dotted line is the center of rotation during SPECT acquisition. If the LV can be placed
within the dotted line, high-quality images canbe acquired by taking advantage of the highsensitivity and high-resolution characteristics ofthe semiconductor detector. However, as the
LV deviates from the dotted line, both sensitivity and resolution decrease. When the bodythickness was 6 cm, as shown in Fig.9-2, LV
could not be placed within the dotted line, resulting in a contrast ratio and visual evaluationof the defect that were lower than those witha body thickness of 0 cm. However, since thisdevice is a semiconductor detector, the averagevisual evaluation score of the 6 cm thick defectwas 3.2 points, which is higher than average.
It is possible to visually evaluate even such athick body thickness. However, higher quality
images would be provided by the semiconductor detector by placing the left ventricle within
the dotted line as much as possible, especiallywhen imaging obese patients. Since this study
used a solid fat-equivalent phantom, it was notpossible to collect more ideal SPECT images

Fig.9-2 Positioning image withbody thickness 6 cm

Fig.9 Positioning image of myocardium when we collected SPECT
with body thickness of 0 and 6 cm in D-SPECT
Arts and Sciences ◆ 57

by moving fat to the side or to the back of thephantom. However, when SPECT is collected
for obese patients in clinical examinations,
positioning is performed so that the fat on thefront of the chest is moved to the side and backso that the LV can be placed within the dotted
line, making full use of the high image quality
potential of semiconductor detectors.
Conversely for the Brightview, the contrast
ratio and visual evaluation of the defect did notchange with different body thicknesses (n.s.).
AGCs have lower sensitivity and resolution
than SDGCs, so the image quality is low evenwhen the body thickness is 0 cm. In addition,
the acquisition time was 50 sec/step, yielding
enough counts even with an increase in bodythickness up to 6 cm. Comparing the contrast
ratio and visual evaluation of the defect in bothdevices, the contrast ratio of the defect was
higher in the SDGC than in the AGC for all
body thicknesses. Because the semiconductor
detector has high sensitivity and high resolution, the image quality of the gamma cameraof the semiconductor detector is better thanthat of the anger-type gamma camera even if
the image quality decreases due to the bodythickness for SDGC. To provide a high-quality
image of a thick body with a SDGC, it is necessary to collect LV counts with a certain threshold value as described above.
As for the FWHM of the defect, both devices
showed almost no change in the FWHM of thedefect (n.s.) with increasing body thickness.
In D-SPECT, as the body thickness increased,
the image quality of the defect decreased; and,it was hypothesized that the FWHM would
decrease as well. However, as the body thickness increased, the pixel value at the center ofthe myocardial thickness and the pixel value
at the defect portion fluctuate as the scattering
component increases. Therefore, it is assumed
that the FWHM measured from the accumulation intensity profile curve did not change
significantly in the 1 cm defect. For Brightview,

58 ◆ Journal of JART English edition 2020

increasing the body thickness up to 6 cm has
little effect on image quality and no effect on
FWHM.
In this study, a defect was created only in theanterior wall of the myocardium, and physicaland visual evaluations of the defect were performed. The appearance of the defect differs
depending on the location of the defect (anterior wall, lateral wall, septal wall, and inferiorwall) with respect to the detector 10). In the
future, we would like to investigate the effects
of image quality on each defect using bothdevices, depending on the body thickness. In
addition to differences in defect appearance,
the position of the heart may vary in patients.
Such conditions as congenital heart disease
may preclude placing the heart near the SPECT
center of rotation. Lastly, how the degree of
deviation in the X, Y, and Z-axis of the SPECT
center of rotation affects image quality should
also be investigated.

5. Conclusion
Our results suggest that changes in bodythickness have a greater effect on image quality for the SDGC than the AGC. When performing SPECT acquisition of obese patients with
SDGC, the heart must be placed in the SPECT
center of rotation as much as possible so thatimage quality does not deteriorate. It is also
necessary to acquire SPECT by setting a threshold value for LV counts.
This research was presented at the 34 th Japan
Conference of Radiological Technologists (Yamaguchi).

6. Acknowledgments
We would like to thank and acknowledge
the following: Mr. yuto Itou, Chibune General
Hospital, and Mr. Keigo Yoshimura, Aizawa
Hospital.

the original work
The effect of body thickness on image quality using either a semiconductor detector gamma camera or Anger-type gamma camera when performing a myocardial
perfusion SPECT: A Phantom study

References
1） Hansen CL, et al.: Effect of patient obesity on the accuracy of thallium-201 myocardial perfusion imaging.
Am J Cardiol, 85, 749-752, 2000.
2） Koji N, et al.: Comparison Between Prone and Upright
Imaging of the Inferior Wall Using 201TlCl Myocardial
Perfusion SPECT. J Nucl Med Technol, 45, 304-308,
2017.
3） Koji N, et al.: Breathing-related body movement fromthe motion of the Rib Cage in Myocardial Perfusion
SPECT -Using Optical Tracking System-. The japan
Society of Education for Radiological Technologists,
10, 3-11, 2018.
4） Sharir T, et al.: High-speed myocardial perfusion imaging initial clinical comparison with conventional dual
detector anger camera imaging. JACC Cardiovasc
Imaging, 1, 156-163, 2008.
5） Erlandsson K, et al.: Performance evaluation of DSPECT: a novel SPECT system for nuclear cardiology.

Phy Med Biol, 54, 2635-2649, 2009.
6） Ryo N, et al.: Quantitative upright-supine high-speed
SPECT myocardial perfusion imaging for detectionof coronary artery disease: correlation with invasivecoronary angiography. J Nucl Med, 51, 1724-1731,
2010.
7） Yasuhiro S, et al.: High-speed molecular imaging DSPECT. The Japanese Society of Nuclear Cardiology,
16, 24-25, 2014.
8） Hayato I, et al.: For image acquisition method in the
CZT gamma camera -Discovery NM530c-. The Japanese Society of Nuclear Cardiology, 16, 28-29, 2014.
9） Hiroyoshi F, et al: Kakuigakugijyutusouron [Introduction to Nuclear Medicine Technology], Yamashiro
Printing Co., Ltd., 251-252, 2014.
10）Akihiro K, et al.: Study of defects depiction performance in the myocardial dedicated semiconductor
SPECT system. Bulletin of Hokkaido University of Science, 40, 95-99, 2016.

Arts and Sciences ◆ 59

Arts and Sciences
the original work

Received November 21, 2018; accepted February 21, 2019

Examination of education for radiological protection/staff exposure reduction by occupationthat radiological technologists should conduct inteam medicine
Kyoichi Kato1）, Ikuko Sakurada2）, Daisuke Kittaka1）, Miwa Ohsawa3）,
Kanako Numanyu4）, Koushi Sakiyama3）, Hisaya Sato1）, Ryu Ohishi 5）,
Chizuko Masuda6）, Hiroshi Suzuki 7）, Eiichi Geshi 8）1）Showa University Graduate school of Health Sciences2）Department of nursing, Aomori Prefectural Central Hospital3）Department of Radiological technology, Showa University Fujigaoka Hospital4）Department of Radiological technology, Showa University Hospital5）Department of Clinical engineering, Showa University Hospital6）Showa university, Division of Nursing7）Department of cardiology, Showa University Fujigaoka Hospital8）School of Health sciences, Showa University

Note: This paper is secondary publication, the first paper was published in the JART, vol. 66 no. 801: 26-34, 2019.
Key words: Radiation protection, Exposure reduction education, team medicine【Abstract】

In the catheterization laboratory, physicians, nurses, clinical engineers, and radiological technologists are engaged intheir respective duties.
However, individuals are exposed to different learning methods and have different comprehension levels onradiation depending on their occupation.
In the present study, we clarified the knowledge on radiation protection and radiation exposure reduction for each
occupation and examined future initiatives regarding radiation education.
In conclusion, as promoting team medicine, radiological technologists should form the core of radiation education.
In addition, by understanding the degree of comprehension based on differences in occupation, reconstruction andcontinued implementation of radiation education and staff radiation reduction education system should necessarily beconsidered based on the expertise and specialty of each occupation.

Introduction
The angiography room is a division wheremultidisciplinary cooperation can be practiced.
Among which, professions such as doctors,
nurses, clinical engineers (CE), and radiological technologists (RT) work in the cardiac catheterization laboratory (cath lab), and as part ofteam medicine, the RT plays a central role inproviding radiation education.
In 1994, the Food and Drug Administration(FDA) of America reported patients with radiation-induced injury to the skin. Thereafter, in
2001, the International Commission on Radiological Protection (ICRP) recommended the

60 ◆ Journal of JART English edition 2020

ICRP publication 85, and in Japan also, efforts
were actively made to reduce radiation exposure.1) Furthermore, in August 2012, the ICRP
announced that the safe equivalent radiationdose for radiation workers should be reduced
from 150 mSv/year to an average of 20 mSV/
year over five years (with no single year exceeding 50 mSv/year),2) and efforts to reduceradiation exposure of patients as well as medical professionals became more important thanever.
Therefore, in focusing on reducing radiation
exposure of medical professionals, upon reflecting on education methods and the level ofcomprehension of radiation, it was thoughtthe original work
Examination of education for radiological protection/staff exposure reduction by occupation that radiological technologists should conduct in team medicine

that there might be a difference according toeach profession cooperating in the cath lab.
To date, many studies on radiation education
have been reported; 3-8) however, there are noreports including multiple professions. In thepresent study, we aimed to elucidate knowledge about radiation protection and reducing
radiation exposure of medical professionals
among each profession, and examined how toundertake radiation education in future.

Methods
The subject sample included 29 cardiologists, 34 nurses, 46 CE, and 51 RT working in
the cath lab of four affiliated university hospitals. We conducted a questionnaire survey consisting of 18 items including ʻawareness of radiation protection (questions 1 – 4)ʼ, ʻknowledge
about radiation protection (questions 5 – 9)ʼ,ʻknowledge about radiation (questions 10 – 15)ʼ,ʻawareness of team medicine (questions 16 – 17)ʼ,and ʻopportunity for radiation education (question 18)ʼ.

Subjects were given a choice of ʻyesʼ or ʻnoʼ
according to their self-evaluation to make responses as clear and as easy as possible. Multiple responses were permitted for ʻopportunities to learn about radiationʼ. (Table 1)
Based on the results obtained, we examineddifferences according to profession, and necessary educational content for each profession
from the perspective of team medicine. Furthermore, we examined the trend in individuals with qualifications, and the difference according to the presence or absence of certification for each profession.
We conducted an analysis using a chi-squared
test to find a significant difference according to
the presence or absence of certification (p<0.05).
The questionnaires were anonymous, andperformed by way of leaving the questionnairewith the subjects and collected at a later dateduring the survey period was from October 2 –10, 2017. Furthermore, study participation was
voluntary, with questionnaire collection considered to imply consent for study cooperation.

Table 1 Questionnaire items
1 Are you concerned about radiation exposure?

Yes・No2 Do you know your exposure dose for a month?

Yes・No3 Do you work with consciousness of radiation reduction?

Yes・No4 Do you want to work in a department involved in assisting radiological department?

Yes・No5 Can you explain the three principles of external radiation protection?

Yes・No6 Can you explain the dose limit of occupational exposure?

Yes・No7 Can you explain how much radiation can be reduced by protective clothing?

Yes・No8 Can you explain the standing position where there are few exposures when approaching a patient?

Yes・No9 Can you explain the correct mounting position of the personal dosimeter?

Yes・No10 Can you explain direct and scattered rays?

Yes・No11 Can you explain the IVR room dose distribution?

Yes・No

12 Can you explain the difference between radiation dose during fluoroscopy and radiography?

Yes・No13 Can you explain the difference between Sv and Gy?

Yes・No14 Can you explain the threshold doses of deterministic effects?

Yes・No

15 Do you know diagnostic reference levels?

Yes・No16 Do you feel a sense of unity with the radiological technologist as a team?

Yes・No17 Will the radiological technologist explain about radiation?

Yes・No18

Please answer the opportunity to learn about radiation. (Multiple answers allowed)
In-hospital workshop · In the work · academic meeting · research meeting · internet · magazine · others（）

Arts and Sciences ◆ 61

Table 2 Details of subjects who completed the questionnaire survey
Job category

Number ofpeopleCertification
Year of experience
number ofqualified persons 0.5〜2（year） 3〜4（year） 5〜6（year） 7〜10（year） 11〜27（year）

Doctor

29

13

5

6

4

9

Nurse

34

4

14

15

2

3

0

Clinical engineer

46

4

11

10

5

8

12

Radiological technologist

51

12

22

9

9

7

4

Results
The collection rate was 100%. Among the 29
cardiologists, there were 13 specialists of cardiac catheterization treatment; among the 34
nurses, there were 4 certified intervention nursing experts; among the 46 CT, there were 4certified cardiovascular intervention experts;
and among the 51 RT, there were 12 experts
with qualifications of the Japan Society of Angiography and interventional Radiology. The
mean length of experience was 7.5 years for
cardiologists, 5.2 years for nurses, 7.6 years for
CE, and 6.6 years for RT. (Table 2)
The proportion of responses accounting forʻyesʼ and ʻnoʼ for each question according toprofession is presented below. Furthermore,
the proportion of individuals with qualifications is presented in brackets.

5

To the question ʻ3. Do you work consciously to
reduce your radiation dose? ʼ, the response wasʻyesʼ by 89.7% (50.0%) of cardiologists, 94.1%(12.5%) of nurses, 80.4% (10.8%) of CT, and94.1% (25.0%) of RT. The response was ʻnoʼ by
10.3% (0.0%) of cardiologists, 5.9% (0.0%) ofnurses, 19.6% (0.0%) of CE, and 5.9% (0.0%) of
RT. (Fig.1)
To the question ʻ4. Do you wish to work in a
department involved in assisting radiation treat-

Awareness of radiation protection

To the question ʻ1. Are you concerned about
radiation exposure? ʼ, the response was ʻyesʼ by
86.2% (48.0%) of cardiologists, 76.5% (11.5%)of nurses, 63.0% (6.9%) of CE, and 41.2%(19.0%) of RT. The response was ʻnoʼ by 13.8%(25.0%) of cardiologists, 23.5% (12.5%) of nurses, 37.0% (11.8%) of CE, and 58.8% (26.7%) of
RT. (Fig.1)
To the question ʻ2. Do you know your radiationdose for one month? ʼ, the response was ʻyesʼ by
27.6% (37.5%) of cardiologists, 58.8% (15.0%)of nurses, 41.3% (21.1%) of CE, and 74.5%(31.6%) of RT. The response was ʻnoʼ by 72.4%(47.6%) of cardiologists, 41.2% (7.1%) of nurses, 58.7% (0.0%) of CE, and 25.5% (0.0%) of
RT. (Fig.1)

62 ◆ Journal of JART English edition 2020

Fig.1 Questionnaire responses to ʻawareness ofradiation protection (questions 1-3)ʼ

the original work
Examination of education for radiological protection/staﬀ exposure reduction by occupation that radiological technologists should conduct in team medicine

ment? ʼ, the response was ʻyesʼ by 48.3% (42.9%)of cardiologists, 35.3% (16.7%) of nurses, 34.8%(12.5%) of CE, and 66.7% (32.4%) of RT. The
response was ʻnoʼ by 51.7% (46.7%) of cardiologists, 64.7% (9.1%) of nurses, 65.2% (6.7%)of CE, and 33.3% (5.9%) of RT. (Fig.2)
Knowledge about radiation protection

To the question ʻ5. Can you explain the threeprinciples of external radiation protection? ʼ, theresponse was ʻyesʼ by 58.6% (52.9%) of cardiologists, 79.4% (14.8%) of nurses, 37.0% (17.6%)of CE, and 98.0% (24.0%) of RT. The response
was ʻnoʼ by 41.4% (33.3%) of cardiologists,
20.6% (0.0%) of nurses, 63.0% (3.4%) of CE,
and 2.0% (0.0%) of RT. (Fig.2)

Fig.2 Questionnaire responses to ʻawareness ofradiation protection (question 4)ʼ,ʻknowledge about radiation protection(questions 5-6)ʼ

To the question ʻ6. Can you explain the dose
limit for workplace radiation exposure? ʼ, the response was ʻyesʼ by 31.0% (44.4%) of cardiologists, 32.4% (36.4%) of nurses, 13.0% (33.3%) of
CE, and 76.5% (28.2%) of RT. The response
was ʻnoʼ by 69.0% (45.0%) of cardiologists,
67.6% (0.0%) of nurses, 87.0% (5.0%) of CE,
and 23.5% (8.3%) of RT. (Fig.2)
To the question ʻ7. Can you explain how muchradiation exposure can be reduced by protective
clothing? ʼ, the response was ʻyesʼ by 37.9%(54.5%) of cardiologists, 35.3% (33.3%) of nurses, 15.2% (42.9%) of CE, and 62.7% (34.4%) of
RT. The response was ʻnoʼ by 62.1% (38.9%) of
cardiologists, 64.7% (0.0%) of nurses, 84.8%(2.6%) of CE, and 37.3% (5.3%) of RT. (Fig.3)

Fig.3 Questionnaire responses to ʻknowledge
about radiation protection (questions 7-9)ʼ

Arts and Sciences ◆ 63

To the question ʻ8. Can you explain the position with little exposure when approaching thepatient? ʼ, the response was ʻyesʼ by 69.0%(60.0%) of cardiologists, 70.6% (16.7%) of nurses, 41.3% (21.1%) of CE, and 80.4% (29.3%) of
RT. The response was ʻnoʼ by 31.0% (11.1%) of
cardiologists, 29.4% (0.0%) of nurses, 58.7%(0.0%) of CE, and 19.6% (0.0%) of RT. (Fig.3)
To the question ʻ9. Can you explain the correct
position for wearing a personal dosimeter? ʼ, theresponse was ʻyesʼ by 75.9% (45.5%) of cardiologists, 73.5% (16.0%) of nurses, 73.9% (8.8%)of CE, and 96.1% (24.5%) of RT. The response
was ʻnoʼ by 24.1% (42.9%) of cardiologists,
26.5% (0.0%) of nurses, 26.1% (8.3%) of CE,
and 3.9% (0.0%) of RT. (Fig.3)
Knowledge about radiation

To the question ʻ10. Can you explain direct radiation, and scattered radiation?ʼ, the response
was ʻyesʼ by 44.8% (53.8%) of cardiologists,
50.0% (23.5%) of nurses, 28.3% (23.1%) of CE,
and 90.2% (21.7%) of RT. The response wasʻnoʼ by 55.2% (37.5%) of cardiologists, 50.0%(0.0%) of nurses, 71.7% (3.0%) of CE, and 9.8%
(40.0%) of RT. (Fig.4)
To the question ʻ11. Can you explain radiation
distribution in the interventional radiology (IVR)
room? ʼ, the response was ʻyesʼ by 27.6% (75.0%)of cardiologists, 29.4% (30.0%) of nurses, 26.1%(8.3%) of CE, and 52.9% (40.7%) of RT. The
response was ʻnoʼ by 72.4% (33.3%) of cardiologists, 70.6% (4.2%) of nurses, 73.9% (8.8%)of CE, and 47.1% (4.2%) of RT. (Fig.4)
To the question ʻ12. Can you explain the difference in radiation dose during fluoroscopy and xray imaging? ʼ, the response was ʻyesʼ by 58.6%(70.6%) of cardiologists, 29.4% (30.0%) of nurses, 15.2% (14.3%) of CE, and 82.4% (28.6%) of
RT. The response was ʻnoʼ by 41.1% (8.3%) of
cardiologists, 70.6% (4.2%) of nurses, 84.8%(7.7%) of CE, and 17.6% (0.0%) of RT. (Fig.4)
To the question ʻ13. Can you explain the difference between Sv and Gy? ʼ, the response wasʻyesʼ by 27.6% (50.0%) of cardiologists, 29.4%

64 ◆ Journal of JART English edition 2020

Fig.4 Questionnaire responses to ʻknowledge
about radiation (questions 10-12)ʼ

(10.0%) of nurses, 26.1% (8.3%) of CE, and82.4% (28.6%) of RT. The response was ʻnoʼ by
72.4% (42.9%) of cardiologists, 70.6% (12.5%)of nurses, 73.9% (8.8%) of CE, and 17.6%(0.0%) of RT. (Fig.5)
To the question ʻ14. Can you explain thethreshold dose of radiation for deterministic effects?ʼ, the response was ʻyesʼ by 44.8% (46.2%)
of cardiologists, 29.4% (30.0%) of nurses, 4.3%
(0.0%) of CE, and 78.4% (30.0%) of RT. The
response was ʻnoʼ by 55.2% (43.8%) of cardiologists, 70.6% (4.2%) of nurses, 95.7% (9.1%)
of CE, and 21.6% (0.0%) of RT. (Fig.5)
To the question ʻ15. Do you know the diagnosis reference level?ʼ, the response was ʻyesʼ by
17.2% (40.0%) of cardiologists, 14.7% (40.0%)
of nurses, 0.0% (0.0%) of CE, and 66.7% (35.3%)

the original work
Examination of education for radiological protection/staﬀ exposure reduction by occupation that radiological technologists should conduct in team medicineof RT. The response was ʻnoʼ by 82.8% (45.8%)of cardiologists, of nurses 85.3% (6.9%), 100.0%(8.7%) of CE, and 33.3% (0.0%) of RT. (Fig.5)
Awareness of team medicine

To the question ʻ16. Do you feel that at one as
an RT and as a team?ʼ, the response was ʻyesʼ

by 93.1% (48.1%) of cardiologists, 58.8% (5.0%)of nurses, 80.4% (5.4%) of CE, and 84.3%(27.9%) of RT. The response was ʻnoʼ by 6.9%
(0.0%) of cardiologists, 41.2% (21.4%) of nurses, 19.6% (22.2%) of CE, and 15.7% (0.0%) of
RT. (Fig.6)
To the question ʻ17. Does the RT explain radiation to you?ʼ, the response was ʻyesʼ by ofcardiologists 86.2% (48.0%), 55.9% (5.3%) ofnurses, 60.9% (7.1%) of CE, and 80.4% (29.3%)

Fig.5 Questionnaire responses to ʻknowledge
about radiation (questions 13-15)ʼ

of RT. The response was ʻnoʼ by 13.8% (25.0%)of cardiologists, 44.1% (20.0%) of nurses, 39.1%(11.1%) of CE, and 19.6% (0.0%) of RT. (Fig.6)
To the question ʻ18. What opportunities doyou have to learn about radiation? (multiple answers permitted)ʼ, cardiologists, nurses, and CE
responded that they had the opportunity tolearn while working, whereas RT responded
that they had equal opportunities at conferences and while working. Other opportunities
included conferences for cardiologists, the Internet for nurses, training sessions for CE, andseminars for RT.
The results and significant differences according to the presence or absence of qualifications

The results of the test for significant differences are presented in tables 3 – 8. A significant difference (p<0.05) was exhibited by cardiologists for concern about radiation exposure and the difference between Sv and Gy; bynurses for the desire to be engaged in assistance of radiation treatment, knowledge of the
reduction of radiation exposure from protec-

Fig.6 Questionnaire responses to ʻknowledge
about team medicine (questions 16-17)ʼ

Arts and Sciences ◆ 65

Table 3 Significant difference according to the presenceor absence of qualifications (questions 1-3)

Table 5 Significant difference according to the presenceor absence of qualifications (questions 7-9)

1. Are you concerned about radiation exposure?

7. Can you explain how much radiation can be reduced
by protective clothing?

Job category

Certification

Noncertification

Yes

Yes

No

significant
differenceNo

Job category

Certification

Noncertification

significant
difference

Doctor

12

1

13

3

P<0.05

Yes

No

Yes

Nurse

3

1

23

7

n.s

Doctor

6

7

5

No
11

n.s

4

0

8

22

P<0.05

Clinical engineer

2

2

27

15

n.s

Nurse

Radiological technologist

4

8

17

22

n.s

Clinical engineer

3

1

4

38

n.s

Radiological technologist

11

11

21

18

n.s

Chi-square test

2. Do you know your exposure dose for a month?
Job category
DoctorCertification

Noncertification

Yes

No

Yes

No

3

10

5

11

significant
difference
n.s

Nurse

3

1

17

13

n.s

Clinical engineer

4

0

15

27

n.s

Radiological technologist

12

0

26

13

n.s

Chi-square test

3. Do you work with consciousness of radiation reduction?
Job category

Certification

Noncertification

significant
difference

Yes

No

Yes

Doctor

13

0

13

No
3

n.s

Nurse

4

0

28

2

n.s

Clinical engineer

4

0

33

9

n.s

Radiological technologist

12

0

36

3

n.s

Chi-square test

Chi-square test

8. Can you explain the standing position where there arefew exposures when approaching a patient?
Job category

Certification

Noncertification

significant
difference

Yes

No

Yes

Doctor

12

1

8

No
8

n.s

Nurse

4

0

20

10

n.s

Clinical engineer

4

0

15

27

n.s

Radiological technologist

12

0

29

10

P<0.05Chi-square test

9. Can you explain the correct mounting position of thepersonal dosimeter?
Job category

Certification

Noncertification

significant
difference

Yes

No

Yes

Doctor

10

3

12

No
4

n.s

Nurse

4

0

21

9

n.s

Clinical engineer

3

1

31

11

n.s

Radiological technologist

12

0

37

2

n.s

Chi-square test

Table 4 Significant difference according to the presenceor absence of qualifications (questions 4-6)

Table 6 Significant difference according to the presenceor absence of qualifications (questions 10-12)

4. Do you want to work in a department involved in assisting radiological department?

10. Can you explain direct and scattered rays?

Job category
DoctorCertification

Noncertification

significant
difference

Yes

No

Yes

No

6

7

8

8

n.s

Nurse

2

2

10

20

P<0.05

Clinical engineer

2

2

14

28

n.s

Radiological technologist

11

1

23

16

n.s

Chi-square test

5. Can you explain the three principles of external radiation protection?
Job category

Certification

Noncertification

Yes

Yes

No

significant
differenceNo

Doctor

9

4

8

8

n.s

Nurse

4

0

23

7

n.s

Clinical engineer

3

1

14

28

n.s

Radiological technologist

12

0

38

1

n.s

Chi-square test

6. Can you explain the dose limit of occupational exposure?
Job category
DoctorCertification

Noncertification

Yes

No

Yes

No

4

9

5

11

significant
difference
n.s

Nurse

4

0

7

23

n.s

Clinical engineer

2

2

4

38

n.s

Radiological technologist

11

1

28

11

n.s

Chi-square test

66 ◆ Journal of JART English edition 2020

Job category

Certification

Noncertification

significant
difference

Yes

No

Yes

Doctor

7

6

6

No
10

n.s

Nurse

4

0

13

17

n.s

Clinical engineer

3

1

10

32

n.s

Radiological technologist

10

1

36

4

n.s

Chi-square test

11. Can you explain the IVR room dose distribution?
Job category

Certification

Noncertification

significant
difference

Yes

No

Yes

Doctor

6

7

2

No
14

n.s

Nurse

3

1

7

23

P<0.05

Clinical engineer

1

3

11

31

P<0.05

Radiological technologist

11

1

16

23

n.s

Chi-square test

12. Can you explain the difference between radiationdose during fluoroscopy and radiography?
Job category

Certification

Noncertification

significant
difference

Yes

No

Yes

Doctor

12

1

5

No
11

n.s

Nurse

3

1

7

23

P<0.05

Clinical engineer

1

3

6

36

n.s

Radiological technologist

12

0

30

9

P<0.05Chi-square testthe original work
Examination of education for radiological protection/staff exposure reduction by occupation that radiological technologists should conduct in team medicine

Table 7 Significant difference according to the presenceor absence of qualifications (questions 13-15)
13. Can you explain the difference between Sv and Gy?
Job category

Certification

Noncertification

significant
difference

Yes

No

Yes

Doctor

4

9

4

No
12

Nurse

1

3

9

21

n.s

Clinical engineer

1

3

11

31

n.s

Radiological technologist

12

0

30

9

n.s

P<0.05Chi-square test

14. Can you explain the threshold doses of deterministic
effects?
Job category
DoctorCertification

Noncertification

Yes

No

Yes

No

6

7

7

9

significant
difference
n.s

Nurse

3

1

7

23

n.s

Clinical engineer

0

4

2

40

n.s

Radiological technologist

12

0

28

11

n.s

Chi-square test

15. Do you know diagnostic reference levels?
Job category

Certification

Noncertification

significant
difference

Yes

No

Yes

Doctor

2

11

3

No
13

n.s

Nurse

2

2

3

27

P<0.05

Clinical engineer

0

4

0

42

P<0.05

Radiological technologist

12

0

22

17

n.s

Chi-square test

Table 8 Significant difference according to the presenceor absence of qualifications (questions 16-17)
16. Do you feel a sense of unity with the Radiological
technologist as a team?
Job category

Certification

Noncertification

significant
difference

Yes

No

Yes

Doctor

13

0

14

No
2

n.s

Nurse

1

3

19

11

n.s

Clinical engineer

2

2

35

7

n.s

Radiological technologist

12

0

31

8

n.s

Chi-square test

17. Will the Radiological technologist explain about radiation?
Job category

Certification

Noncertification

significant
difference

Yes

No

Yes

Doctor

12

1

13

No
3

n.s

Nurse

1

3

18

12

n.s

Clinical engineer

2

2

26

16

n.s

Radiological technologist

12

0

29

10

n.s

Chi-square test

tive clothing, radiation distribution in the IVRroom, the difference in radiation dose between
fluoroscopy and X-ray imaging, and the diagnosis reference level; by CE for radiation distribution in the IVR room, and the diagnosis reference level; and by RT for the position to approach the patient, and the difference in radiation dose between fluoroscopy and X-ray imaging.

Discussion
Cardiologists and nurses had a high level ofawareness and knowledge of their own radiation protection; however, they had insufficient
basic knowledge about radiation. In particular,
the threshold dose for radiation-induced skin
injury and crystalline lens injury was only understood by less than half of subjects, which
we believe needs to be taken into due consideration, and addressed in future education as
an important item.
We found that CE were aware of, but had
insufficient knowledge of radiation protection.
Furthermore, they had insufficient basic knowledge about radiation, and require educationthat enables them to obtain knowledge about
radiation protection, as well as basic knowledge about radiation.
RT exhibited a high rate of understanding for
all items; however, with regards to radiation
education for nurses and CE (17. Does the RT
explain to you about radiation?), we found thatfew subjects responded ʻyesʼ. Therefore, fromthe perspective of team medicine, it was suggested that as radiation specialists, at present,
RT do not adequately transmit the knowledge
required in practical settings to other professionals. RT need to reflect back on whether,
despite having expert knowledge of radiation,
they inadequately shared such knowledge toother cooperating professionals. All four hospital affiliated with our university held seminars
on radiation protection, and reducing radiation
exposure of patients and medical professionArts and Sciences ◆ 67

als; however, we found that ultimately they
were not made use of. While taking into account the frequency and period of seminars
held, further careful investigation is needed toenable radiation education to be performedthat is suited to the particularities of each profession. Moreover, the phrase ʻ if there is anything you donʼt understand, please ask ʼ is used
often in practical settings; however, it should
also be understood that individuals do notknow what questions to ask.9) Therefore, as aradiation expert, it is thought that RT should
step up further to help medical professions ofother departments. For example, in various settings during tests, having others understandwhere the radiation dose is currently low, isparticularly important knowledge for nurses
who ask patient complaints, provide nursing
care, and approach the patient often. Understanding radiation distribution will allow action to what position currently has little radiation exposure based on the arm angle and direction of the X-ray device, and from whereapproach should be made to the patient to reduce oneʼs own radiation exposure. This similarly applies to CE, and is knowledge that wehope is given priority and understood better.
RT should understand the expertise and behavior pattern of each professional, and accordingly should provide education suited toclinical practice.
Excluding RT, we found that other professions did not fully understand ʻ knowledge
about radiationʼ. Professionals other than RT
had few opportunities to learn basic knowledge of radiation in basic education, and whenlooking at the educational curriculum of nurse
and CE training schools, 10-12) there are no classes in regard to radiation, which we believe
might be one reason underlying their lack ofunderstanding. In the future, we hope that radiation-related education will be implemented
as part of team medicine.
With regards to cardiologists, we found thatfew responded ʻyesʼ to being able to explain

68 ◆ Journal of JART English edition 2020

radiation distribution in the IVR room, and thedifference between the radiation dose of fluoroscopy and X-ray imaging. This item is extremely important information for cardiologists
performing irradiation not only in terms of
their own radiation protection but also fromthe perspective of team medicine. Furthermore, we believe that understanding this item
helps nurses and CE to show considerationsuch as avoiding unnecessary fluoroscopy and
X-ray imaging and communicating when approaching the patient. Furthermore, althoughmore than 80% of cardiologists responded thatthey were concerned about radiation exposure, less than 30% knew the dose of radiation
to which they were exposed over a month. We
believe that cardiologists concerned over theirown personal radiation protection will lead tothe reduction of radiation exposure of the patient, as well as that of the staff cooperating asa team.
Depending on the presence or absence ofqualification acquisition, we found a significant
difference according to different items. We believe that this is attributed to the fact that there
were opportunities to receive radiation education when acquiring or continuing qualifications. However, few items showed a significant
difference, and based on this result, it isthought that even after acquiring qualifications,ongoing education and training is needed.
Irrespective of the presence or absence ofqualification acquisition, an environment andopportunities need to be created whereby all
professionals engaged in radiation can obtainongoing education and related knowledge
about radiation. Based on the questionnaire results, most opportunities to learn radiation education were provided while on duty, and webelieve that institutions should not only provide education for their staff, but that education should proceed with the RT of the institutions at the core. Moreover, it is important toexamine the content of such education collectively among each profession. In future, wethe original work
Examination of education for radiological protection/staff exposure reduction by occupation that radiological technologists should conduct in team medicine

believe that it is important for the RT to endeavor to communicate better with other professions, and to make a greater effort in radiation education as team medicine.13-15)
Furthermore, we believe that this will lead tothe ʻpromotion of team medicineʼ 16) so-calledby the team medicine promotion council.

Limitations and prospects of thepresent study
The present study included cardiologists,
nurses, CE, and RT working in the cath lab offour hospitals affiliated with our university,
which limited the survey range. As future prospects, we believe that performing a large-scalequestionnaire survey with doctors of each department engaged in radiation procedures will
increase the number of responses including
the parameters of individuals with qualifications, and help to find detailed results.

Conclusion
In the present study, we aimed to elucidate
knowledge about radiation exposure of cardiologists, nurses, CE, and RT working in thecath lab. In promoting team medicine, upon
centering radiation education on the RT, andReferences
1） the International Commission on Radiological Protection; ICRP: ICRP publ.85「Avoidance of Radiation Injuries from Medical Interventional Procedures」, 2001.
2） ICRP: ICRP Statement on Tissue Reactions / Early
and Late Effects of Radiation in Normal Tissues andOrgans – Threshold Doses for Tissue Reactions in a
Radiation Protection Context. ICRP Publication 118.
Ann. ICRP 41(1/2). 2012.
3） Rie Kamishina, et al.: Clinical on-site action of thenurse who received education about the radioprotection in a course of the nursing basic education. Innervation, 21(6), 84-87. 2006.
4） Kyoichi Kato, et al.: The influence that radiation exposure reduction education gives. Cardiovascular Intervention and Therapeutics, 22(1), 74-77. 2007.

thoroughly determining the level of understanding according to different professions, it
is important to reconstruct an education systemtaking into account the expertise and particularities of each profession, and provide ongoing education.

Ethics and conflicts of interest
The present study was conducted with theapproval of the ethical review board of affiliated institutions, and there are no conflicts ofinterest to declare.

Acknowledgements
In proceeding with the present study, we
would like to express our deepest gratitude to
everyone at the Division of Cardiology Department of Medicine, Department of Nursing, Department of Clinical Engineering, and Department of Radiological Technology at Showa
University for their cooperation.
An outline of this study was published at the82nd Annual Scientific Meeting of the Japanese
Circulation Society, the 8th Co-medical award
lecture (March, 2018, Osaka), and the 66th Annual Scientific Session of the Japanese College
of Cardiology (September 2018, Osaka).

5） Reiko Kanda, et al.: About the recognition in the fundamental researches – nurse for risk communication
about the medical radiation exposure –. JSRT, 64(8),937-947. 2008.
6） Yoshiaki Morishima, et al.: Importance of the radiation
education judging from the attitude survey about theradiation of the nursing student. Jpn. J. Radiat. Saf.
Manage, 13(2), 173-176. 2014.
7） Tomoko Kato, et al.: Recognition of the radiologist for
the role of the nurse in the radiation medical treatment
and the medical treatment skiagrapher. The journal ofRadiological Nursing Society of Japan, Vol.6, No.1,
3-11, 2018.
8） Yukari Masujima, et al.: Survey by about recognition
and the radiation education for the occupation radiation exposure nurse engaging in IVR. The journal ofArts and Sciences ◆ 69

Radiological Nursing Society of Japan, Vol.6, No.1,
12-21, 2018.
9） Naomi Miyake, et al.: To Ask a Question, One Must
Know Enough to Know What Is Not Known. Journal of Verbal Learning and Verbal Behavior Vol.18(3)pp357-364, 1978.
10）Showa Univercity (2018)「Department Curriculum silabus」, [online] http://www.showa-u.ac.jp/sch/pharm/
curriculum.html (Reference 2019-1-5)
11）Tokyo Engineering Univ. (2018)「Health medical care
department Clinical engineering department Curriculum」, [online] https://www.teu.ac.jp/gakubu/medical/
clinic/curriculum2014.html (Reference 2018-11-4)12）Kyorin University (2018)「Health department curriculum」, [online] http://www.kyorin-u.ac.jp/univ/faculty/
health/ (Reference 2019-1-5)

70 ◆ Journal of JART English edition 202013）Ministry of Health, Labour and Welfare: About promotion of the team medical care (Study meeting reportabout the promotion of the team medical care Study
meeting report). March 19, 2010.
14）Ministry of Health, Labour and Welfare: Basic way of
thinking for team medical care promotion and practical casebook, team medical care promotion policy
examination working group, team medical care promotion meeting, June, 2011.
15）Miwako Hoshoda: It is health medical sociology
essays ... from the viewpoint of the healthcare workerof the each some – with “the team medical care”, No.
12, 88-101, 2001.
16）A team medical care communication meeting: About ameeting, it is an idea of the team medical care (2018)[online] https://www.team-med.jp/philosophy (Reference 2018-11-4)

Arts and Sciences
the original work

Received September 1, 2017; accepted March 29, 2019

Development of the Dual Flip-Flop Angle Type
T2W-Fast Spin Echo Method
Kojiro Yamaguchi
Faculty of radiological technology, School of Health Science, Fujita Health University, Aichi, Japan＊
Current affiliation：Department of Radiological Technology, Faculty of Medical Technology,
Niigata University of Health and Welfare, Niigata, Japan

Note: This paper is secondary publication, the first paper was published in the JART, vol. 66 no. 804: 14-21, 2019.
Key words: Fast Spin echo, T2W, Bloch equation, specific absorption ratio, contrast noise ratio【Abstract】

Fast Spin echo is a major sequence used for T2WI. The 90 (Flip) angle - 180 (Flop) angle - echo - 180 (Flop) angle echo train sequence is the basic pattern in FSE. Major drawbacks of the technique are the increase in SAR anddecrease in CNR. To overcome these problems a Flip-Flop angle type sequence, a T2WFSE was developed. Optimal
Flip and Flop angles must be selected to develop the Flip-Flop type sequence of T2WFSE. The Bloch equation wasapplied in order to develop the sequence used for the evaluation of MR signal strength in numerical simulation.
Optimal Flip and Flop angles were selected by numerical simulation based on the Bloch equation for the Flip-Flopangle type T2WFSE.

1. Introduction
In the clinical setting, imaging a wide range
with a thin slice thickness in a very short time
period is required in Magnetic Resonance Imaging (MRI). A T2-weighted (T2W) sequenceis a very effective scanning method for thedetection of diseases. However, its efficacy islimited by the long repetition time (TR) in T2W
imaging. This consequently increases the scantime. Relaxation Enhancement (RARE) typeT2W sequence Fast Spin Echo (FSE) was proposed as a means of shortening scan times 1).
FSE is a method of shortening scan times. This
technique involves the use of multi-echo spinecho techniques that allow more data to becollected. Chunks of k-space are gathered ata time consequently reducing scan times. FSE
sequence is commonly used in current clinicalpractice.
Despite the advantages of the FSE technique,
it is limited by two major drawbacks. The firstproblem is the rise in specific absorption rate(SAR) 2). The safety of radio frequency (RF)pulse exposure during clinical MRI is regulated
and monitored. The RF pulse sequences usedin the FSE sequence are 90 °(α) - 180 °(2α)
type, based on Spin Echo sequence. The basic
pattern of RF pulses for the FSE is 90 °- 180 °Spin Echo excitation pulse pattern followedby multiple 180 °refocusing pulses. Therefore,
the same number of 180 °pulses are repeatedly exposed to get the required number of
echoes in FSE. These 180 °refocusing pulses
cause the increase in SAR level which consequently increases the thermal effect 3), 4). The
second disadvantage of FSE is the decrease insoft tissue contrast in multi-slice imaging. This
reduction in image quality occurs as a result of
the magnetization transfer (MT) effect causedby the RF pulse, an issue frequently encountered in the FSE method 5), 6). For the reasons
discussed above the development of a new
FSE sequence free of these two drawbacks has
been requested.
Yamaguchi proposed a method to solvethese problems. This method involves modification of the shape of the RF pulse not only
Arts and Sciences ◆ 71

to reduce the SAR, but to also improve thecontrast of multi-slice imaging 7). However,
MRI scanners used in clinical settings are notequipped with the ability to use Yamaguchiʼsmethod because it requires the modification of
the RF pulse. Hennig et al. Proposed a technique of reducing the angle of 180 °refocusing
pulses to overcome the SAR issue 8), 9). Thesemethods were achieved by fixing the angle of
RF either the 90 °pulse or the 180 °pulses 10).
Hahn studied α°(Flip) - β°(Flop) instead of
the RF pulse 90 °(α) - 180 °(2α) 11). For thisstudy, we developed an FSE sequence with an
RF pulse pattern of α°(Flip) - β°(Flop) andevaluated it in relation to SAR reduction andcontrast noise ratio (CNR) improvement.

2. Method

TR, TE, T1 and T2.

(1)

(2)

(3)

Mx, My, Mz : Components, γ: Gamma, gyromag-

netic ratio, ω : Angular frequency in radians
per second, B0 : Static magnetic field, B1 : Amplitude of the RF field, TR : Repetition time, TE :Echo time, ρ: Proton density, T1 : Longitudinal
recovery time, T2 : Transverse relaxation time,
Flip : Excitation Pulse, Flop : Refocusing Pulse.

2.1 The in-plane signal value and echo signal
value.

A combination of the angles for Flip (Excitation Pulse) - Flop (Refocusing Pulse) is important if different angles are used. Echo Time
(TE) in the FSE sequence is needed for the
calculation of the combination of angles. Twoequations were used to simulate the MRI signal
values needed to obtain the optimal Flip-Flopangles. The Equation (1) is the Bloch equation. The Bloch equation enables numericalsimulation of MR signals. The RF pulse profileand gradient magnetic field strength, TR, TE,
T1 and T2 are necessary factors in numericalsimulation of the Bloch equation. Mx, My, andMz components are calculated from the Blochequation. The Mxy component that gives the
MRI signal values is then calculated from theEquation (2) accordingly 12), 13). The next Equation (3) gives the echo signal value as a simplified form of the Bloch equation 14). Althoughboth the RF pulse profile and gradient magnetic field strength are necessary factors in numerical simulation of the Bloch equation, weused the Equation (3) to obtain an adequate
calculated of the echo signal value with only

72 ◆ Journal of JART English edition 2020

2.2 The optimization of Flip-Flop.

Normalization maps were drawn to determine the optimal angles for the Flip-Flop sequence. First, the values from each equation
were normalised to allow the comparison of
the results. This was necessary given the difference in the outcome of the simulation with the
Equation (2) and (3). Two maps were drawn.
One was based on the result of the calculation using the Equation (2) for each signal
from Flip-Flop. A Normalization map was also
drawn using the result attained from the Equation (3). Next, the Equation (4) was used toobtain curves that have the same attenuation
ratio of 1.0. An optimal curve was determinedfor each echo based on the Equation (4).
1.0 ＝Normalized in - plane signal value
Normalized echo signal value(4)

2.3 Parameters for the calculation of in-planesignal value and echo signal value in numerical simulation.

The detail of the used parameters are following: TR = 4,500 ms, TE = 14.2 ms, 28.5 ms, 42.8

the original work
Development of the Dual Flip-Flop Angle Type T2W-Fast Spin Echo Method

ms, 57.1 ms, 71.4 ms, 85.7 ms, 100 ms, 114.3
ms, 128.6 ms, 142.9 ms, 157.2 ms, 171.5 ms
and 185.8 ms, Flip angle = 50 °- 130 °(5 °step),
Flop angle = 110 °- 180 °(5 °step), Slice thickness = 5 mm, The target substance was Gray
Mater of brain. Gray Matter (T1 = 809 ms, T2 =101 ms 15). The total number of the numericalsimulation was 6,630. The analysis software
used was Mathematic 4.0 and 6.0.
2.4 The evaluation of the optimal angles onclinical equipment.

We examined the physical evaluation for
imaging by the optimum Flip-Flop angle obtained by numerical simulation in the clinicalmachine.
2.4.1 Analysis of Flip-Flop Angle Control

When changing the Flip-Flop angle, it is necessary to check whether the Flip-Flop angle
can be accurately controlled at a specified
angle. In this confirmation, the crest value of
the RF waveform in the magnetic field wasmeasured by measuring the RF waveform in
the magnetic field using the search coil andchanging according to the Flip-Flop angle. For
the measurement range, the flip angle is 60 degrees to 120 degrees and the flop angle is 120
degrees to 180 degrees.
2.4.2 RF uniformity analysis at Flip-Flop angle

At the Flip-Flop angle, there a problem is
encountered as to whether the RF pulse is uniformly applied to the substance.
To verify this problem, the RF pulse homogeneity test was conducted using a tissue
equivalent phantom formed with the dielectric conductor (filler: copper sulfate solution
0.055%, conductivity: about 0.3 S/m).
The imaging conditions as follows, TR/TE =400/15 ms, FOV = 300 mm, matrix: 256 × 256,
slice thickness: 10 mm, NEX = 2, Acquire image: Sagittal, MRI unit: EXCELART/Pianissimo
1.0T (Toshiba Medical Systems).

2.4.3 Physical evaluation of images

The evaluation using the optimal Flip-Flopangles was conducted on a scanner in clinicalsettings. Measurements of slice thickness, Signal to Noise Ratio (SNR), and SAR were conducted as physical evaluation 16). A 1.0 Tesla
MRI (Toshiba Medical Systems) was used.
2.5 Image analysis

For the evaluation of actual images, one
healthy subjectʼs brain was scanned and the
CNR of gray matter and white matter on animage from multi slice imaging was measured 17), 18). Informed consent was obtained
from the subject prior to conducting the scan.
Comparisons were made between a 90 °- 180 °sequence and the Flip-Flop 0 sequence regarding the drop rate of CNR in multi-slice scans.
Signals from gray matter and white matter
were calculated by averaging five sets of data.
Each size of the region of interest (ROI) was
circular, 4 × 4 (total of 16) pixels. A particularslice plane was selected so we could set the
ROI on both the white and grey matter areas.
The scan conditions as follows: TR = 4,500 ms,
Effective TE = 100 ms, Echo Train Length =13, Slice thickness = 5 mm, Slice gap = 1 mm,
Number of slices = 22, Field of View = 300 mm
× 300 mm. Matrix size = 256 × 256. A 1.5 Tesla
MRI system (Philips Medical Systems) scanner
was used for the CNR evaluation.

3. Results
3.1 The optimization of Flip-Flop.

Normalization maps of the in-plane signal
values and echo signal values are shown in
Fig.1 and Fig.2. The two maps shown havecompletely different patterns. Fig.1 (in-planesignal value map) shows an egg-shaped curve.
The range around the maximum signal value isdifferent to the one from 90 °- 180 °sequence.
In contrast, the echo signal value shows a rectilinear pattern. The combination of the angle
at which the signal value reaches its peak is
Arts and Sciences ◆ 73

Fig.1 Normalization map of In-plane signal value

Fig.3 The optimal curve calculated from equation

The contour diagram of the in-plane signal values obtained from the Bloch equation (Equation 1) and the inplane signal value (Equation 2) showed an egg shape.
The in-plane signal value of the center indicated.

The optimization curve obtained from equation 4.
And a curve indicates a range showing 1.0. However,
it is not possible to limit the optimum Flip-Flop angle
form this curve.

Fig.2 Normalization map of echo

Fig.4 The curves show the optimal value whenvarying the TE 14.2 ms to 185.8 ms

Contour lines of the signal values of the Echo signal value (Equation 3) showed a linear change andshowed a shape different from the Bloch equation.

The optimization curve shown in Figure 3 in shownfor each TE. The flip-flop angle at which the optimization curve arrogates to one point wan taken as the
optimum Flip-Flop angle.

at 90 °- 180 °sequence. The optimal curve calculated from the Equation (4) is indicated byarrows in Fig.3. The curve indicated by the arrows is at the level of 1.0 in signal strength.

is attributed to the value that has not been
influenced by TE. TE 200 ms was not used as
the results obtained largely deviated from 105 °- 145 °sequence.

3.1.1 Flip-Flop evaluation in relation to TE.

3.2 Evaluation results on the clinical equip-

The diagram is shown below (Fig.4 ) describes the optimal value when shifting TE
14.2 ms to 185.8 ms. Optimal values of eachcurve are focused at the point of the combination near 105 °(Flip) - 145 °(Flop) sequence.
It was determined that the angle combination

74 ◆ Journal of JART English edition 2020

ment.
3.2.1 Flip-Flop Angle Control
Fig.5 shows the peak value measurement

result of the RF pulse in the magnetic field of
the search coil. The correlation coefficient of
the peak value with respect to the input angle

the original work
Development of the Dual Flip-Flop Angle Type T2W-Fast Spin Echo Method

Fig.5 Accuracy of RF pulse in magnetic field(a), (b): RF pulse waveform in magnetic field, (c): The Flip angle and the voltage of the RF
pulse in the magnetic field [Vpp], (d): Flop angle and voltage of RF pulse in magnetic field[Vpp].

a) 90°- 180° sequenceb) 105°- 145° sequenceFig.6 Evaluation of uniformity of RF pulse
As for the 105°- 145° sequence in which the Flip-Flop was varied, like the 90°- 180° sequence, the signal value contour was not different in shape.

Arts and Sciences ◆ 75

Table 1 The result of slice thickness and SNR
measurements with two different combinations
Flip-Flop

Slice thickness

SNR

90°- 180°
sequence

5.7 ± 0.26

38.9 ± 0.1

105°- 145°
sequence

5.7 ± 0.27

39.7 ± 0.2［mm］

Image Acquisition Condition.
TR/TEeff = 4,500/100, 13 echo, ST/Gap = 5.0/1.0 mm,
NS = 22 Slice, FOV = 300 mm, 256 × 256 matrix, NEMA
Phantom.
Slice thickness and SNR is not different between 105°
- 145° sequence and 90°- 180° sequence.

of the Flip-Flop showed high correlation and it
was 0.9952 and 0.9979 at R2.
3.2.2 RF uniformity analysis at Flip-Flop angle
Fig.6 showed the results of the RF pulse uni-

formity test at the optimum Flip-Flop angle. In

the 90 °- 180 °sequence, the contour plot at thecenter of the phantom is shown. On the other
hand, even at 105 °- 145 °sequence, contour
plot showing the same shape as 90 °- 180 °sequence was shown.
3.2.3 Physical evaluation results

The result of the physical evaluation isshown in Table 1 below. This indicates that
there is no significant difference in SNR andslice thickness when using the combination of
the angles of 105 °- 145 °sequence.
3.3 The Brain imaging evaluation.
Fig.7 shows Ax T2W images of the brain of a
subject. No remarkable artifact is evident in theimages. CNR of Gray Matter and White Matter for the 90 °- 180 °sequence and the 105 °- 145 °sequence are 37.8 and 47.8 respectively.

Fig.7 Images of the brain of the subject
Image Acquisition Condition.
TR/TEeff = 4,500/100, 13 echo, ST/Gap = 5.0/1.0 mm, NS = 22 Slice, FOV = 300 mm, 256 × 256
matrix, Head Coil.
Measurement points of CNR are shown. No significant artifact was obtained by 105°- 145° sequenced imaging.

76 ◆ Journal of JART English edition 2020

the original work
Development of the Dual Flip-Flop Angle Type T2W-Fast Spin Echo Method

There is an improvement of 20.9% in the CNR
when using the 105 °- 145 °sequence. The SAR
showed on the clinical machine for which CNR
was obtained was 1.37 [W/Kg] and 2.06 [W/Kg]
with 105 - 145 degree echo train and 90 - 180
degree echo train. We can reduce 33.6% of SAR
with the 105 °- 145 °sequence compared to the
90 °- 180 °sequence.

4. Discussion
Factors required for diagnosis are spatial
resolution or contrast resolution. The spatial
resolution of multi-slice computed tomography(CT) in recent years has been superior to othermedical imaging modalities. MRI maintains its
advantage in contrast resolution over CT. However, low contrast resolution in FSE has beena problem in clinical practice. For this reason,
minimising the degradation of contrast resolution is important for more optimal clinicalpractice. This article recommends the use of
the Flip-Flop angle other than the angle of 90 °- 180 °as a viable solution to this problem.
Two equations were used in this study to
calculate the MR signal values needed to obtainthe Flip-Flop angle. The in-plane signal values
and echo signal values are calculated from theEquations (2) and (3) The optimal value wasfound from the results and the optimal curve(Fig.4) was obtained to determine the FlipFlop angle.
It is possible to obtain the Flip-Flop angle
while at the same time maintaining contrast
resolution. In addition, the optimal the FlipFlop angles 105 °- 145 °were found from eachcurve having different TE. Image artifact was
not seen from the angles used on brain scan
images using a test subject.
The study yielded some improvement in soft
tissue contrast resolution, which increased by
24.3%. In addition to that, there was also a
reduction of 33.6% in SAR. The above results
indicate that the contrast resolution of the FSE
sequence can be improved by changing theFlip-Flop angle. Further evaluation is necessary
to confirm the efficacy of the Flip-Flop methodon imaging in the clinical setting.

5. Conclusion
The angle of the RF pulses used in the FSE
sequence is generally 90 °(α) - 180 °(2α). This
causes the degradation of soft-tissue contrast
resolution and increases the SAR. A new FSE
sequence that doesnʼt employ 90 °- 180 °RF
pulse combination was designed. This new
FSE sequence has a combination angle of 105 °- 145 °in relation to Flip-Flop. Using this technique enables us to improve the contrast resolution of soft tissue as well as reduce SAR.

Acknowledgements
The authors would like to thank Mr
Yoshitaka Kawai RT., Mr Kenzo Nakamura
RT., Mr Kenzo Baba RT., Mr Nobunari Sato
RT., Mr Eiji Tanaka RT., Mr Kei Sasaki RT., andTeruhisa Ohno RT., for assisting with the study.
This work was supported by JSPS KAKENHI
Grant Number JP15K01732.

Arts and Sciences ◆ 77

References
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10）Meiboom S. and Gill D: Modified spin-echo method
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Second Edition Volume One, Mosby-Year Book, Missouri, pp.109-144, 1992.

Regulations and Requirements for Submissions to the
Journal of the Japan Association of Radiological Technologists
Submission Regulations
Revised: April 1, 2013
October 30, 2013
February 20, 2016
April 20, 2019
Objective

Article 1. These regulations are based on the operations defined in Article 4 of the articles of incorporationof the Japan Association of Radiological Technologists (hereafter “the Association”) andstipulate the criteria for submissions to the Journal and informational magazines published by
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Regulations and Requirements for Submissions ◆ 79

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Requirements for Submissions to the
Journal of the Japan Association of Radiological Technologists
Revised: February 20, 2016
April 20, 2019

The formatting requirements for manuscripts specified in Article 7 of the Journal of the Japan Associationof Radiological Technologists submission regulations are as follows:
1. Formatting of original works, rapid communications, reports, notes, technical material, overview
articles, and review articles
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The first page of the manuscript must be a cover. Please provide the following information:①Submitted manuscripts must clearly indicate the type of submission.
②The title in Japanese and English, authorʼs name, institution name, affiliation, and occupation (pleaseprovide the member numbers of authors and co-authors who are members of the Association).

80 ◆ Journal of JART English edition 2020

③Keywords in English (nouns; no more than five).
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2) Body of the paper①Manuscripts must be written in Japanese or English.
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3
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8
8
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Regulations and Requirements for Submissions ◆ 81

Journal of JART–English edition 2020–

March 1, 2020
Issuer: Yasuo Nakazawa
Publisher: The Japan Association of Radiological Technologists
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