2023
Journal of— E n g l is h e d i t io n —2320

The Japan Association of Radiological Technologists

Journal of2320— 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
UEDA Katsuhiko, President, The Japan Association of Radiological Technologists

History

4

History of The Japan Association of Radiological Technologists (JART)

6

original articles

Arts and Sciences

Supraspinatus Outlet View Accuracy comparison between the conventional
method rotated 100 degrees in X-ray photography and the Horio method
using the central X-rays
TAKAI Natsuki, SUZUKI Yoshiaki, KATO Kyoichi

15

original articles

3D T2 -weighted turbo field echo (3D T2 TFE) sequences for evaluation of
cervical nerve roots
KAWAKAMI Koji, KITSUKAWA Kaoru, KIMURA Yusuke, YONEYAMA Masami, FUKUCHI Hirofumi, YOSHIKAWA Tatsuo

22

original articles

Dosimetry with a custom-made chest radiography dosimeter and radiationdose management from the analysis results
SHINKAI Eishu, OOISHI Tetsuya, TAKAGI Yuu, KATOU Hiroaki, KOMIYA Hiroko, UEDA Kouki, YOSHIKAWA Kumiko, RIKITAKE Sayaka, BABA Ikuko

30

original articles

Content analysis in the proceedings “Study Group on the Appropriate
Management of Medical Radiation”
SAITO Hiroki, TOKUSHIGE Yumiko, MARUYAMA Sho, IWAI Tsugunori, KATOU Hideki, HOSHINO Syuhei

39

original articles

Student issues based on the results of clinical training of radiological
technologists
MUTO Hiroe, NAKAYA Koji, MATSUURA Kanae

47material

The effects of electrical muscle stimulation on facial muscles: Volume change
of facial muscles measured with magnetic resonance imaging
NAKAYA Koji, MUTO Hiroe, MATSUURA Kanae, SUDO Shu, YAMANAKA Aya

55

material

Dementia disease classification of the statistical analysis images of cerebral
blood flow SPECT using deep learning
YAMAMOTO Yasushi, SHIRAI Masato, KATSUBE Takashi, YOSHIZAKO Takeshi, UWABE Hoshio, MIYAHARA Yoshinori, KITAGAKI Hajime

63material

Research on eye lens exposure doses and exposure management forphysicians involved in Interventional Radiology
ARAI Kazumasa, WATANABE Hiroshi, MEGURO Yasuhiro, KITAYAMA Sanae, YABE Satoshi, SASAKI Takeshi, HASEGAWA Takeshi,
FUKUZUMI Toru, KAWASAKI Hideo, SATO Yoichi

76

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 2023

F o r e w o r dRegarding Publication of the
English Edition
UEDA Katsuhiko (President)

The journal of the JART English version issues every year. It has a favorable reception for wemembers of the world and general people. As well as this issue, 8 articles to be useful for radiological technologists are issued.
We will feature clinical, educational, and research-based achievements by radiological technologists in the monthly issues of the JART journal, and continually work to improve the magazine. I
truly hope that this English edition will benefit radiological technicians worldwide.
To give our radiological technologists from across the globe an insight into our business, I will
briefly explain the history of the JART. In March 1896, we succeeded in taking the first X-ray image
in Japan. 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. The 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 in June 1951, we were finally able to see the promulgation of the Radiology X-ray
Technicians Act, Act No.226 of 1951. Since then, we have responded to the changing needs of thesociety, revising the original act to get the Radiology X-ray Technicians Act of 1968 passed, andpartially revising that to get the Radiology Technicians Act and Radiology X-ray Technicians Act of1983 passed, and finally getting the Radiology Technicians Act, which is in place currently, 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, and non-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 and hemostasis, lower
digestive tract examination (anal catheter insertion and administration of contrast medium), anal
catheter insertion, and oxygen inhalation during radiation therapy were added as operations that
could be performed by radiological technologists.
In October 2021, the needle insertion for examinations of contrasting of the examination for CT,
MRI, Ultrasound and Radioisotope are added as the new operation that can be performed by radiological technologists.
The JART will continue to respond to the needs of the medical industry, and we hope to broaden
the operational scope of radiological technologists based on our foundation in scientific evidence.

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)

1983

1985

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

1954

1956

1962

1968

First national examination for Medical Radiographers (May 30)
Event to commemorate the 10th anniversaryof founding, attended by Her Imperial Highness Princess Chichibunomiya
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

1979

1987

1989

1991

1993

1994

1995

1996

Event to commemorate the 80th anniversaryof the discovery of X-rays, attended by Her
Imperial Highness Princess Chichibunomiya

1998

Completion of the Education Center for
JART

1999

4 ◆ Journal of JART English edition 2023

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 Technologists

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

Partial revision of the Act on Medical Radiographers and the Act on Radiological Technologists (unification of the professions)

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

2000

2001

2003
2004

2005

2006

Launch of the Radiological Technologists
Liability Insurance System with participationby all members“ Presentation of the Medical Exposure
Guidelines (Reduction Targets)” for patients

2013
Start of the Radiological Technologists Liability Insurance System
Enactment of X-Ray Week

2014

Relocation of offices to the World Trade
Center Building in Tokyo

Launch of the radiation exposure advisor
certification system

2015

Revision of the Medical Exposure Guidelines

2008

2009

2017
Establishment of the committee on Autopsy
imaging (Ai)2018
Revision to the national examination for radiological technologists
Launch of the Team Medicine Promotion
Conference, with the President of JART as its
representative
Appointment of the President of JART as
chairperson of the Central Social Insurance
Medical Council specialist committee

2010

2011

Health Policy Bureau Directorʼs notification
concerning promotion of team medicine
Support activities following the Great East
Japan Earthquake
Staging of an extraordinary general meeting
concerning transition to a public interest incorporated association

2012

2019

2020

2021

Renaming as public interest incorporated association JART

Event to commemorate the 120th anniversaryof the discovery of X-rays
Event to mark the 70th anniversary of founding (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
Partial revision of the Ordinance on Prevention of Ionizing Radiation Hazards
Relocation of offices to the Mita Kokusai Building in Tokyo
Partial revision of the designation regulation
for radiological technologist training school

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)

Consignment of work to measure personal
exposure of residents
Revision of the Act on Radiological Technologists, Government Ordinance to Partially
Revise the Enforcement Orders, and Revisionof the Enforcement Regulations (June 25)

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

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

Holding the 23th AACRT with 37th JCRT in
Tokyo

2022

Event to mark the 75th anniversary of founding (July 16)

History of JART ◆ 5

Arts and Sciences
original articles

Received April 7, 2021 ; accepted June 30, 2021

Supraspinatus Outlet View Accuracy comparison between the conventional method rotated
100 degrees in X-ray photography and the Horio
method using the central X-rays
TAKAI Natsuki1），SUZUKI Yoshiaki2），KATO Kyoichi3）1）Medical examination center, Mitsubishi-kobe hospital2）Department of Radiology, Shimoda medical center3）Showa University Graduate School of Health Sciences

Note: This paper is secondary publication, the ﬁrst paper was published in the JART, vol. 69 no. 831: 32-39, 2022.
Key words: Supraspinatus Outlet View, Y-View, Scapula, Reference line, Radiography【Abstract】

This study examined which, between the conventional method of rotating the scapula 100 degrees and Horioʼs
method of using the central X-ray connecting the root of spine of scapula (the scapular spine triangle) and the centerof the glenoid cavity, satisﬁed the visualization conditions of the Supraspinatus Outlet View.
The conventional method and the Horio method were reproduced by 3D-CT of 40 cases of scapula, and thetangentiality of the scapula body in the left-right rotation direction was compared. For the upward and downward
rotation directions, the parallelism with the central X-ray indicated by Horio was evaluated using the base of thesupraspinatus fossa as an index.
As a result, the tangentiality of the scapular body in the left-right rotation direction was 9.39 mm ± 3.81 mm in theconventional method and 2.22 mm ± 2.34 mm in the Horio method, which was signiﬁcantly higher with the Horio
method.
When the Horio method was used, the parallelism in the upward and downward rotation directions was− 0.15°± 1.55°.
It was proved that the Horio method satisﬁes the drawing condition of Supraspinatus Outlet View, in comparison
with the conventional method.

1. Introduction
In the Y-view on X-ray imaging, the center ofthe glenoid cavity of the scapula and humeral
head overlap, with the sides formed by the acromion, scapular spine, and supraspinatus; thesuperior angle and coracoid process; and the
body of the scapula forming a Y-shape 1). The
Y-view is used to observe changes to the bonyelements of the shoulder joint and their relative
positions, as well as the subacromial joint, andseparates the scapula from the ribs.
There are two ways to take images in the Yview: the trans-scapular lateral view 2, 3) and thesupraspinatus outlet view 3–7). The majority ofJapanese documents on X-ray imaging techniques describe the supraspinatus outlet view

6 ◆ Journal of JART English edition 2023

(hereinafter, Y-view). In this method, the subacromial joint space can be visualized byobliquely shooting the X-ray craniocaudally,
which effectively captures osteophyte formation under the acromion, shape of the undersurface of the acromion, and calciﬁcation of
the rotator cuff stop (Acromio-Humeral interval: AHI) 5, 8, 9). In addition, X-ray in the Y-view
is effective for its main purpose, which is theobservation of the shoulder joint; e.g., dislocation of the humeral heads and acromioclavicular joint, fracture of the clavicle, scapula, andhumerus, osteophyte under the acromion, tumor of the scapula and humeral neck, andsnapping scapula syndrome 5, 8, 9, 10).
An X-ray in the Y-view is taken correctly under the following conditions: overlap of a) theoriginal articles
Supraspinatus Outlet View Accuracy comparison between the conventional method rotated 100 degrees in X-ray photography and the Horio method using the central X-rays

lateral border of the body of the scapula, whichis the axillary fossa side, and b) the medial border of the body of the scapula, which is the
spinal 10). The tangential imaging of the anterior
surface of the scapula 6) also reveals that the
body of the scapula is separated from theribs 2, 3, 10–12). Furthermore, a wide view of thesubacromial joint formed by the acromion andhumeral head 13) and X-rays taken at an angle
tangential to the supraspinatus must be obtained 11), i.e., the subacromial region must be
observed tangentially. Images that do not fulﬁllthese conditions will not allow visualization of
the components of the shoulder joint in the Yshape. In other words, the relationship between the scapula and humeral head will be
distorted, hindering the diagnosis of fractures,dislocations, and ligament injuries, which is
detrimental to ensuring reproducibility duringfollow-up.
Speciﬁcally, the method involves the straightsegment of the posterior border of the scapularspine (which can be palpated from the bodysurface) being rotated horizontally 100 to theimage-receiving area 12, 14-16). This method (henceforth, the conventional method) is extensively
documented. However, different documents
describe the angle of incidence of the X-rays in
the upward direction as 0 , 10 , 15 , and 20
with the angle being applicable to all patients 1, 3, 14, 16). Additionally, X-rays taken in the
Y-view in clinical practice have required many
reexaminations due to differences between patient position and scapular anatomy, which result in distortions of the scapular Y-view in lateral, upper, or lower rotations. In particular, forpatients with rounded backs, the Y-view of the
X-rays is taken in the recumbent position,
which requires further adjustments to achieve
appropriate visualization of the scapula.
It is necessary to use not only a single indicator, as in the conventional method, but also to
identify the central X-ray that connects thepoint of incidence and point of exit of the Xray for the body of the scapula. However, tothe best of our knowledge, Horioʼs (1971)
study is the only one that described the central
X-ray in the Y-view as the scapular spine triangle and glenoid cavity 17), and this expression
has not been used in any of Horioʼs subsequentstudies. In addition, no studies have examinedthe validity of the two points presented by
Horio for the Y-view. It is necessary to reexamine the body surface index because stable imaging cannot be achieved with the body surface index in Y-view as described in the current literature, and the incidence angle varies
between references. In this case, it is important
to use the central X-ray of the patientʼs scapula
as a reference in Y-view. This and other imaging methods result in changes in the patientʼs
position according to their posture and shoulder movement.
Here we report our experience using threedimensional (3D) computed tomography (CT)in the conventional method and an alternative
method that uses the scapular spine triangle
and glenoid cavity that form the central X-rays(hereinafter, the Horio method) to determine
which method meets the conditions of visualization in Y-view more effectively.

2. Methods
2-1. Ethical considerations

The data from this retrospective study wasanonymized. The ethics committee of our institution approved this study.
2-2. Devices and subjects

A 64-row CT scanner (Optima CT660 Pro
15HW25.2, GE Healthcare Japan Co., Ltd.) andworkstation (SYNAPSE VINCENT Ver.5.4, Fujifilm Medical Co., Ltd.) were used for constructing 3D images. The CT was acquired with arotation time of 0.5 s, 64 × 0.625 mm opticalsight, 5.0 mm section thickness, 0.984 mm beam
pitch, 78.75 mm/s table feed speed, 500 mm scan
range, 120 kV tube voltage, 100–500 mA tube
current. The images were reconstructed at 350
Arts and Sciences ◆ 7

mm image reconstruction and 500 mm reconstruction ﬁeld of view. Chest CT obtained 40
scapular images of 22 patients from May 2018
to October 2019 for a diagnostic purpose different from this study, in which the entire scapula (21 right, 19 left; 13 males, 9 females; ages
33–88 years; mean age 61.3 ± 16.0 years) wereanalyzed.
2-3. Method of determining central X-ray as areference point concerning the scapula
Fig.1 depicts the point of the scapular spine

triangle, which is the point of incidence of the
X-ray with respect to the scapula in Y-view imaging, and the X-ray exit point, i.e., the glenoid
cavity. Fig.1-a represents the 3D scapular image of the point of incidence in Y-view, i.e.,
the root of the spine of the scapula (scapula
spine triangle), which is deﬁned as the point ofintersection (●) between the line that extends
from the superior border of the scapular spine
to the medial border of the scapula (solid line)
and the line originating at the inferior angle
extending to the base of the supraspinatus(broken line) 8). As shown in Fig.1-b, the glenoid cavityʼs point of exit corresponds to thepoint (×) where 1) the longitudinal axis (bro-baRoot of spineof scapula (RS)ken line) connecting the uppermost and lowest points of the glenoid cavity (supraglenoid
and infraglenoid tubercle), and 2) the line connecting the most anterior and posterior bordersof the glenoid cavity (solid line) cross perpendicularly (hereinafter, center of the glenoid
cavity) on the view that allows its frontal observation 17). Next, as shown in Fig.1-c, the line
connecting these two reference points, i.e., theroot of the spine of the scapula (scapula spine
triangle) and center of the glenoid cavity, isdeﬁned as the Y-view central axis.
2-4. Evaluation of left–right rotation on Y-view

The left–right rotation direction of the scapula is indicated by the overlap between the lateral and medial borders of the body of thescapula, which is required for an effective Yview 10) indicates. As depicted in Fig.2, reference points for evaluation were placed on the
medial and lateral borders to ﬁnd if the conditions are met for an effective Y-view., the tangentiality of the lateral and medial lines in the
Y-view in the conventional method and the
Horio method, which relies on the scapularspine triangle and the glenoid cavity, were assessed. The percentage of overlap between thecCenter of the
glenoid cavity (C)C

Y‐View central axis

RS

(Scapula spine
triangle)

Fig.1 Position of point of incidence of the X-ray（root point of the spine of the scapula）and the point
Fig. 1 （Positionof thepointof incidence
theTheX-ray(rootcentral
point ofthe spine of the scapula)of injection
center of
glenoid
cavity）ofand
Y-Viewaxis
and the point of injection (center of the glenoid cavity) and The Y-View central axis
a. The root point of the spine of the scapula (The scapular spine triangle)（●）
b. Center a.
of theglenoid cavity（×）
The root point of the spine of the scapula(The scapula spine triangle)(●)（solid）c. The Y-View
centrallinecavity(✕)
b. Center axisof theglenoidc.

The Y-View central axis (solid line)

8 ◆ Journal of JART English edition 2023

original articles
Supraspinatus Outlet View Accuracy comparison between the conventional method rotated 100 degrees in X-ray photography and the Horio method using the central X-raysaSuperior angleof scapulabc

The superior angle of the scapula（■）
The inferior angle of scapula（▲）（●）
Thebaseangleof thesupraspinalThesuperiorof thescapula (■)fossa=

A
Internal
direction=The
angle ofsolid
scapula(▲)A）■ inferior- ▲（blackline

The base of the supraspinal fossa (●)

C

E C D

E

D

Inferior angleof scapula（C, ○）
The(black
Medialborder●-▲brokenline ofB) the scapula
The Medial border of the scapula (C, ○)The anterior border of the lateral

G
External
direction● - ▲（black broken line B）■-▲ (black solid line A)

F
Anterior
directionThe
anteriorof the lateral（D,border□） ofborderofborderthe scapula
the scapula ( D ,□)B

The
distancefromthe border
lateralThe
distancefrom the lateralanteriorofthescapula (E,△)
anterior
borderof the scapula（E, △）Posteriordirection

BetweenE andECand= (F, white
BetweenC =（arrow)
F, white arrow）

Between D and E = (G, white broken arrow)

Between D and E =（G, white broken
arrow）

Fig.2 Positions of the medial and lateral borders for evaluating tangency in the lateral rotation
Fig. 2 Positions of the medial and lateral borders for evaluatinga. Anterior view image of scapula by 3D-CT VR processing
tangency in the lateral rotationb. Image viewed from the external direction
c. Image viewed from the internal direction
a. Anterior view image of scapula by 3D-CT VR processing
b. Image viewed from the external direction
c. Image viewed from the internal direction

medial and lateral borders and the distance between them were evaluated as indicators oftangentiality using the methods described below:
The Y-view was generated from a 3D CT image and was rotated laterally 90 so that theimage could be viewed from the front. The
horizontal line (white broken line) that perpendicularly crossed the line between the superior angle (■) and inferior angle (▲) of thescapula at the height of the midpoint was deﬁned as the point of intersection on the lateralborder, and its posterior and anterior borders
were denoted as points D (□) and E (△), respectively The point of intersection at the midpoint of the medial border (■ – ▲) was deﬁned as the center of the medial border (C). In
addition, to evaluate the degree to which themedial border of the scapula is more anterior
to the lateral border and tangential to the anterior surface of the scapula, “tangential condition” was deﬁned as the overlap of the medial
border on the anterior half of the thickness of
the lateral border to measure the distance between the anterior lateral border and the medial border. The distance from the anterior lat-eral border (point E △) to the medial border(point C, 〇) (segment E – C ＝ F, white arrow)
was measured and compared to the distancefrom the lateral posterior border (point D, □)to the thickness of the anterior lateral border(point E, △) (segment D – E ＝ G, white broken line arrow).
2-5. Upward and downward rotation on Y-view

Previous studies have described the use of
Y-view imaging to obtain a wide view of thesubacromial joint formed by the acromion andhumeral head 13) and to shoot the X-ray tangentially to the supraspinatus 11). In other words,
this represents the coronal alignment of the
upward and downward rotation of the scapula.
Aoki et al.8) reported that X-ray incidence parallel to the inclination of the supraspinatus wasused as a surrogate reference for the subacromial inclination to draw an appropriate Y-view
image, as the subacromial inclination in thecoronal direction of the body tends to be obscured by subacromial osteophyte formation.
Therefore, tangential visualization of the supraspinatus should be useful for adjusting therotation of the Y-view upwards and downArts and Sciences ◆ 9

The base of
supraspinatus fossa
Superior angleof scapula
Scapular

ｰ

notch

＋

Y‐View central axis

tion, Welchʼs t-test was performed with twocontrol groups, the Horio method (n = 40) andthe conventional method (n = 40), excluding
outliers. To evaluate the consistency of upward
or downward rotation, outliers were eliminated using the Smirnov–Grubbs test, and onesample t-test with the population mean set to
0 (n = 40) was performed. The one-sample Kolmogorov–Smirnov test was, and the Smirnov–
Grubbs test used to assess normality and exclude outliers, respectively. P < 0.01 was considered statistically signiﬁcant.

3. Results
Relationshipbetweensetting
Fig. 3Fig.3
Relationshipbetweenthe thesetting
of ofthethebase of the
3-1. Assessment of left–right rotation on Y-view
base
of
the
supraspinatus
fossa
and
supraspinatus fossa and the Y-View central theaxis in the
Y-View
centralaxis
intheanteriorviewanterior view image of the scapula in 3D-CT Raysum displayFig.4 depicts the distance between the anteimage of the scapula in 3D-CT Raysumrior lateral border and the medial border in thedisplay
The scapular notch (○)

wards. Using this as a reference, we determined whether the Y-view generated the Horio
method also fulﬁlled the criteria of a Y-view
image. As depicted in Fig.3, the angle formedby the Y-view central axis and the straight segment of the supraspinatus base was measured
on an image of the scapula observed frontallyin a 3D CT Raysum view. The base of the supraspinatus was deﬁned as the straight segment visible in the frontal Raysum view between the scapular notch (lateral) (〇) and thesuperior angle (medial) (■) indicated by thedotted arrow. A rotational correction in the upward direction of the tilt of the straight segment of the supraspinatus base to the Y-view
central axis in the upward direction was deﬁned as + (positive), and a rotational correction in the downward direction was deﬁned asa − (negative).
2-6. Statistical analysis

For consistency evaluation of left–right rota-

10 ◆ Journal of JART English edition 2023

Y-view measured as measured by the Horio
method and the conventional method. The distances were 2.22 ± 2.34 mm and 9.39 ± 3.81mm according to the Horio method and theconventional method, respectively. No outliers
were produced by either method, and there
was a signiﬁcant difference between them (p <0.01).

Distance (mm)Thenotchsuperior
angle of scapula (■)（○）
The scapular
Linearof thebase of the（■）
The superior
anglesectionof scapula
supraspinatus(▼)supraspinatus fossa（▼）
Linear sectionof the basefossaof theY-View
axisline(dashedline)（dashed）
Y-View central
axiscentral

Method using the Horio method

Conventional method in which thespine of the scapulae was rotated by
100 degrees

Classification

Fig. Positions
4 Positionsofofthe
themedial
medial borderborder with
Fig.4
with respect
respectto thelateral borders of the scapula when using the Horio method
to the lateral borders of the scapulaand the conventional method (box plot)when using the Horio method and theconventional method（box plot）

original articles
Supraspinatus Outlet View Accuracy comparison between the conventional method rotated 100 degrees in X-ray photography and the Horio method using the central X-rays

Fig.5 illustrates the position of the medial

method and the conventional method, respectively (Fig.5-A, B). Using the Horio method,
the medial border overlapped with the thickness of the lateral border in 90.0% (36/40) of
the scapulae. Of these, the lateral anterior andmedial borders were visualized completely
tangentially in four scapulae, whereas they did

border relative to the thickness of the lateralborder in the Y-view as determined by the
Horio method and the conventional method.
The thickness of the lateral border as represented by the D–E distance (●) was 13.88 ± 1.66
mm and 12 ± 2.13 mm measured by the Horio

20

Distance (mm)

15

10

5

0
0

A

5

10

-5

B

15

20

25

30

35

40

Number of sample

Half thebetweenbetween
C andHalfdistancethe distanceC andD(▲)D（▲）

20

Positionsof theborder border
Positionsof medial
the medialwith respect
to the lateralof border
with respect
to theborder
lateralthe scapula(■)

18
16

Distance (mm)The lateral
The lateralscapula scapula
border D-Eborder D-E
distance(●) （●）
distance

14of the scapula（■）

12
10
8
6
4
2
0
0

5

10

15

20

25

30

35

40

Number of sample

Fig. 5-A Positions of medial border with respect to the lateral border of

Fig.5-A the
Positionsof medialborderrespect tothe lateral border of the scapula when
scapula whenusing theHorio withmethod(scatter
diagram)using the Horio method（scatter diagram）
Fig. 5-B Positions of the medial border with respect to the lateral borderFig.5-B ofPositions
ofusing
the medial
border withrespect
todiagram)the lateral border of the scapula using
the scapula
the conventional
method(scatterthe conventional method（scatter diagram）

Fig.6 Four
scapulaewherethe medial
bordernot overlap
lateral borderFig.
6 Fourscapulaewhere
the did
medialborderwith
didthenot（○）
The Medialof the scapula
overlap
withborder
the lateralborder

The anterior border of the lateral border of the scapula（□）
The Medial
borderthe scapula(○)
The distancefrom
theoflateralanterior
border of the scapula（△）
The anterior border of the lateral border of the scapula (□)

The distance from the lateral anterior border of the scapula(△)

Arts and Sciences ◆ 11

3-2. Assessment of superior and inferior rotation on Y-view
Fig.7 depicts the angles formed by the Y-

view central axis and the base of the supraspinatus. Angles ranged from -4 to 3 with themean angle of -0.15 ± 1.55 and a distribution
peak at 0 (42.5%, 17/40).

4. Discussion
In this study, the left–right rotation assessment in the Y-view (Fig.5-B) demonstrates thatthe medial and lateral borders of the body ofthe scapula did not overlap in 11 of 40 scapulae imaged using the conventional method andthat the medial border was shifted posteriorly

12 ◆ Journal of JART English edition 2023

18

n=40
Ave：-0.15
SD:1.55

16
14
12
Frequency

not overlap in four scapulae. Fig.6 depicts the3D CT and Raysum images of the four scapulaein which the lateral anterior and medial borders did not overlap. As illustrated in Fig.6, themedial border was anterior to the lateral border in all four scapulae. As depicted in Fig.5-A,
in 97.2% (35/36) of the 36 scapulae in which
the medial border overlapped with the thickness of the lateral border in the Horio method,
the medial border was closer to the anteriorborder than the midpoint of the width of thelateral border, which corresponds to 87.5%(35/40) of all cases.
In contrast, the medial border overlappedwith the thickness of the lateral border by
72.5% (29/40) in the conventional method(Fig.5-B). There was no scapula in which thelateral anterior and medial border could be imaged completely tangentially. In the 11 scapulae where they did not overlap, the medial border was more posterior to the body than thelateral border thickness. In the 29 scapulae inwhich the medial border overlapped with the
thickness of the lateral border, the medial border was closer to the anterior than the midpoint of the width of the lateral border in 31.0%(9/29); which corresponded to 22.5% (9/40) of
scapulae.

10
8
6
4
2
0

-4

-3

-2

-1

0

1

2

3

DegreesFig. 7 Angles between the Y-View central axis and theFig.7 baseAnglesthe
Y-View central axis andof thebetween
supraspinatusfossa
the base of the supraspinatus fossa
When correction in the upward rotation is needed it is assigned as plus.

When correction
thedownward
upwardrotationis needed
it isWhen correctioninin therotationis necessary,it is assigned
asminus.
assigned
as plus.
When correction in the downward rotation is necessary, it
is assigned as minus.

to the posterior surface of the medial border inall 11 scapulae. In 65.5% scapulae in which themedial border overlapped the thickness of thelateral border, the medial border was posterior
to the midpoint of the width of the lateral border, corresponding to a 75.0% deviation ratefrom the tangential condition of the scapularbody. In the conventional method, which uses
a 100 rotation between the straight segment of
the posterior border of the scapular spine andthe image reception area as a reference, showsthat the body is rotated excessively medially tothe ideal position, i.e., with the anterior surfaceof the scapular body positioned tangentially,
which would require the rotation angle to begreater than 100 . However, a simple correction to an angle greater than 100 in the conventional method is ineffective in generating agood Y-view image (Fig.4), as it results ingreater spread due to individual anatomicaldifferences than the Y-view obtained using the
Horio method. This shift is inevitable as longas the straight segment of the posterior borderof the scapular spine is used as the reference
point, resulting in an incomplete Y-view image.
In contrast, the Horio method distributed the
distance between the anterior lateral borderand the medial border in left–right rotation
more uniformly than the conventional method.

original articles
Supraspinatus Outlet View Accuracy comparison between the conventional method rotated 100 degrees in X-ray photography and the Horio method using the central X-rays

Additionally, 90% of the scapulae where themedial border overlapped the thickness of thelateral border had the overlap in the anterior
half of the thickness of the lateral border. Thissuggests that the Horio method allows formore accurate imaging and better conformanceto the conditions of Y-view imaging in left–right rotation than the conventional method. In
four scapulae, the medial border did not overlap with the thickness of the lateral border;
however, all four met the other condition of
the Y-view described in radiographic documents, which is that the body of the scapula isseparated from the ribs 2, 3, 10-12). Therefore, using the Horio method, the body of the scapula
and ribs were found to be separated in all 40
scapulae examined from 22 patients, suggesting that it is a universally valid method ofright–left rotation that permits accurate Y-view
imaging in all patients.
Next, when evaluating upward and downward rotation in Y-view, the condition of accurate imaging in the Y-view, i.e., the base of
the supraspinatus 8, 11) was used as a reference.
As depicted in Fig.7, this resulted in a mean
angle of -0.15 ± 1.55 between the base of thesupraspinatus and Y-view central axis; i.e., itcorresponds well with the base of the supraspinatus, indicating good conformance to thecondition of accurate visualization inn the Yview. This suggests that the method proposedby Horio method to reference the central Xrays in a superior Y-view using the scapularspine triangle and glenoid cavity is an effective
method. Furthermore, this study demonstrated
that the glenoid cavity, as shown by Horio, refers to the cavityʼs center. Therefore, aligning
the angle of incidence of the X-rays to the Yview central axis, which connects the scapularspine triangle and center of the glenoid cavity,
adjusts positioning for both left–right as well as
upward and downward rotation of the scapula,serving as a universal reference unaffected by
the patientʼs postural change, scapular movement, or anatomical differences. The Horio

method generates a more precise and ideal Yview X-ray image than the conventional method, in which the angle of incidence of X-rays isadjusted between 0 and 20 .
This study has several limitations. First, thiswas a single-center, retrospective study, whichcalls for a multi-center prospective study to increase the level of evidence. Next, no comparison was made between the X-ray images
produced by the Horio and conventional methods. This would be unethical as it would expose patients to a higher radiation dose of radiation than is required. Third, for a controlledassessment of the scapular angle, it would benecessary to control the scapulaʼs inclination in
the coronal, sagittal, and horizontal directions,which was not possible with the available Xray images. Fourth, the images of the scapulaein this study were acquired using chest CT,
which is performed with the arms raised, as
opposed to the normal seated or standing position with the arms lowered. However, thisstudy evaluated the scapula independently as
opposed to its relationship with neighboringbones such as the humerus or clavicle andstructures such as muscles; therefore, we consider this irrelevant.
Further investigation is necessary for futurestudies, such as examining body surface references for using the Y-view central axis andnew body surface indices for each posture. If
this is possible, it is expected that the patient
will be able to receive Y-view images that satisfy the imaging conditions even in the hunched
posture and the supine position.

5. Conclusions
A simulation using 3D CT images demonstrated the effectiveness of imaging using thecentral X-ray connecting the two points, thescapular spine triangle and the glenoid cavity,
as shown by Horio as the reference for Y-view
imaging satisﬁed the imaging conditions for theY-view more than the conventional method.
Arts and Sciences ◆ 13

6. Acknowledgments
We would like to express our sincere gratitude to Shimoda Medical Center for their cooperation in this research and to Professor Yasuo
Takatsu of Tokushima Bunri University for his
assistance in preparing this manuscript. A part

References
1） Oda Nobuhiro, et al.: Housyasengijyutsugakusirizu Xsensatsueigijyutsugaku (Revised 2nd edition).
Tokyou: Ohmsha，p228-229, 2014.
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company, 79-180, 2010.
3） Ballinger PW, et al.: Merrillʼs Atlas of Radiographic
Positions and Radiologic Procedures.1,185-187, 190,
204, 214-215, Mosby, 1999.
4） Liotard JP, et al.: Critical Analysis of the Supraspinatus
Outlet View: Rationale for a Standard Scapular Y-view.
J Shoulder Elbow Surg, 7(2), 134-139, 1998．
5） Umer M, et al.: Subacromial impingement syndrome.
Orthopedic Reviews, 9, 4(2), e18, 2012．
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outlet and rockwood caudal tilt views from threedimensional computed tomography scan of theshoulder. AP-SMART, 20, 12-16, 2020.
7） Duralde XA, et al.: Troubleshooting the supraspinatus
outlet view. J Shoulder Elbow Surg, 8(4), 314-319,
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8） Aoki Mitsuhiro, et al.: Kenpou no keisha nori nsho u k e i so ku to su bacro mi al i mpi n g e me nt
syndrome to no kankei. Japan Shoulder Society,14(2), p270-274, 1990.

14 ◆ Journal of JART English edition 2023of this study was presented at the 32nd Annual
Conference of the Japan Association of Radiological Technologists (2016, Gifu).
Conflicts of interests

The corresponding author nor the coauthors
have no conﬂicts of interest to declare.

9） House J, et al.: Evaluation and management ofshoulder pain in primary care clinics. South Med J,
103, 1129-1135, 2010.
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Satsueiho to Sindan ・ Dokuei no Point. Tokyou:
Kanehara Shuppan, 2012.
11）Takakura Yoshinori, et al.: Zukai Joshisatsueiho.
Tokyou: Ohmsha, p24-29, 2011.
12）K a n a m o r i I s a o , e t a l . : S h i n r y o g a z o k e n s a h oXsensatsueiho. Iryokagakusha, p209, 2010.
13）Wu G, et al.: ISB recommendation on definitionsof joint coordinate systems of various joints for thereporting of human joint motion-Part Ⅱ: shoulder, elbow,
wrist and hand. J Biomech, 38(5): 981-992, 2005．
14）Japanese Society of Radiological Technology,
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Japanese Society of Radiological Technology, p80,
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15）Kumagai Sadayoshi: Kotsu Xsensatsueigijutsu.
Tokyou: Ishiyaku Shuppan, p79, 1969.
16）Horio Shigeharu: Kotsu ・ Kansetsu Xsenshashinno Torikata to Mikata. Tokyou: Igakushoin, p15-16,
2010.
17）H o r i o S h i g e h a r u : K o t s u t a n j u n s a t s u e i h o t oXsenkaibozufu. Tokyou: Igakushoin, p242-245, 1971.

Arts and Sciences
original articles

Received March 7, 2021 ; accepted October 16, 2021

3D T2 -weighted turbo field echo (3D T2 TFE)
sequences for evaluation of cervical nerve roots
KAWAKAMI Koji 1）, KITSUKAWA Kaoru2）, KIMURA Yusuke2）, YONEYAMA Masami 3）,
FUKUCHI Hirofumi 1）, YOSHIKAWA Tatsuo1）
1）Imaging Center, St. Marianna University School of Medicine Hospital2）Department of Radiology, St. Marianna University School of Medicine
3）Philips Japan

Note: This paper is secondary publication, the ﬁrst paper was published in the JART, vol. 69 no. 833: 19-24, 2022.
Key words: MRI, cervical spine, nerve root, neurography, 3D T2 TFE【Abstract】

Evaluation of cervical nerve root abnormalities using magnetic resonance imaging is less straightforward for cervicalspondylosis than for spinal cord compression. For better visualization of cervical nerve roots, a three-dimensional T2weighted turbo ﬁeld echo (3D T2 TFE) sequence may be useful, due to the increased signal intensity of nerve bundles,
as well as the rapid black blood imaging. In this study, 3D T2 TFE and 3D T2 volume isotropic turbo spin echoacquisition (3D T2 VISTA) sequences were compared for visualization of nerve roots. Images from 10 volunteers werevisually evaluated and statistically analyzed. The 3D T2 TFE sequence was able to show nerve roots with a signiﬁcantly
higher signal than the surrounding structures. In statistical analysis, 3D T2 TFE provided signiﬁcantly higher nerve root
visualization in C3–C7 vertebrae than did 3D T2 VISTA. Concordance between observers was high. 3D T2 TFE may be
helpful in diagnosing nerve root compression in patients with cervical radiculopathy.

Introduction
Cervical radiculopathy is caused by the compression of the cervical nerve at the level of theintervertebral foramen due to disc bulging or
osteophytes in Luschkaʼs joints or intervertebral joints. Cases that develop spinal canal stenosis and lumbar disc herniation in the lumbar
spine undergo magnetic resonance imaging(MRI) to visualize how the nerve roots arecompressed. However, only a few studies havesought to visualize cervical nerve root andmorphological changes within the intervertebral foramen using MRI 1) - 5). Conventional MRI
imaging methods may have difﬁculty identifying which nerve root is injured and the responsible lesion 6). The intervertebral foramen is
anatomically smaller than the lumbar spine
and is located obliquely to the body axis 5), 7).
During diagnostic imaging of cervical spondylotic radiculopathy, accurate identiﬁcation of
the lesion is important for selecting surgicaltreatment. For this purpose, three-dimensional(3D) imaging methods with thin slices and nogaps between slices have been considered advantageous 6). MR Neurography as the MR Imaging methods for the cervical nerve, includes
3D Volume Isotropic Turbo Spin Echo Acquisition (3D T2 VISTA) sequences 8), and especiallywhen the peripheral nerves are needed to visualize outside the intervertebral foramen, diffusion-weighted imaging and High-Resolution
3D Volumetric Nerve-Sheath Weighted RARE
Imaging (3D SHINKEI) have been reported in
the literature and applied clinically 9) - 13). The
3D T2 VISTA sequences described above is basically a T2-weighted imaging method that delineates cerebrospinal ﬂuid (CSF) and adipose
tissues with a high signal and normal nerveroots, degenerated intervertebral discs, andyellow ligaments with a low signal 8). However,no signiﬁcant difference in the ability to visualize nerve roots in the intervertebral foramen
was observed between the aforementioned
modalities and two-dimensional methods,
making it difﬁcult to observe the nerve roots in
Arts and Sciences ◆ 15

the intervertebral foramen, which are important in cervical spondylotic radiculopathy. In
order to continuously observe a wide area extending from the spinal cord to the anterior
and posterior roots, dorsal root ganglia, andextravertebral foramen nerve roots, imaging
methods that suppress the signal from bloodvessels, CSF, and fatty tissue surrounding thenerve root and emphasize the nerve root itself
are considered effective 10). It has been reported that the 3D T2 Turbo Field Echo (3D T2 TFE)
sequences is capable of high-signal imaging of
nerve ﬁbers, and can obtain three-dimensional
T2-weighted black-blood imaging can be obtained in a short time 13), 14). This method is a
gradient echo (GRE) method that collects spinecho (SE) signals, which require two RF pulses
to generate. In principle, when the echo time(TE) is longer than the repetition time (TR),and the longer TR and TE are, the more sensitive to motion and the lower the ﬂuid tissue
signal can be captured. The current study
aimed to compare the nerve root imaging per1
formance of the 3D T2 TFE sequences and the2
3D T2 VISTA sequences, which allows for a
freely reconstructable in a 33D sequence.
4

1 Methods

5
6

Table 1 3D T2 TFE and 3D T2 VISTA scan parameters
for volunteer imaging
3D T2 TFE
5.9

150

TR（msec）

12

1200

Flip angle（degree）

35

90

TFE（TSE）factor

30

40

Startup echoes

default

0

Shot interval（msec）

439

DRIVE

yes

Uniformity
Proﬁle order

CLEAR

CLEAR

Centric

Sequential

ProSet 121

noBand width［Hz］

271

315

（mm）
Field of view［FOV］

180

180

Rectangular FOV（%）

65.9

66.6

Matrix［matrix×phase］

174×116180×120

Reconstruction matrix

432×432

432×432

Number of signals averaged

4

1

Slice thickness（mm）

1

1

Fat sat

Slice

50

50

Scan time（min）

5.37

4.40

ProSet: Principle of Selective Excitation TechniqueA

16 ◆ Journal of JART English21edition 2023
22

D

D

A
C

C

1.1 Validation of the 3D T2 TFE sequences

7
We performed 3D T2 TFE imaging in 10
8healthy volunteers and veriﬁed
its ability to vi9sualize cervical nerve roots in the images. This
study was approved by the
10 Ethics Committeeof our hospital, and all volunteers were in11
formed of the purpose of the study and pro12
vided consent (Approval No. 3418). The Achie13 Ltd.) and Neurova 1.5-T (Philips Japan Co.,
Vascular coil were used 14
as the receiver coil.
The imaging parameters are
15 shown in Table 1.
The 3D T2 VISTA sequences
16 was based on pre8)
vious studies . whereas the 3D T2 TFE se17
quences was based on phantom veriﬁcation.
18
The measurement position was a transverse
19 cervical vertebra.
image at the level of the ﬁfth
20

3D T2 VISTA

TE（msec）

B

E

E
B

Fig.1 ROI placement for the axial 3D T2 TFE images

Fig.The1 ROI
placementfor ofthetheaxial
3Dacquired
T2 TFEreformatted
axial image
originally
3Dimages
T2 TFE image shows the locations of the ROIs used formeasuring the signal intensity of the right nerve root（A）,
paraspinal muscle（B）, cerebrospinal ﬂuid（C）, left vertebral artery（D）, and left nerve root（E）.

The region of interest (ROI) was set at 4.0 mm,
the image was enlarged sufﬁciently to minimize errors, and the signal intensities of thebilateral nerve roots, paraspinal muscles, CSF,
and left vertebral artery were calculated (Fig.1).
After one-way analysis of variance, the Steel–original articles
3D T2-weighted turbo field echo (3D T2 TFE) sequences for evaluation of cervical nerve roots

1.3 Statistical evaluation of image evaluation

Dwass test was performed for each group to
determine signiﬁcant differences. The conﬁdence interval was set at 99% (p < 0.001). Statistical analysis software JMP Pro®13 (SAS Institute Inc.) was used 15).

The Wilcoxon signed-rank test was used toevaluate the nerve root imaging performanceof the 3D T2 TFE and 3D T2 VISTA sequencesin 10 volunteers, after which kappa values
were used to analyze the interobserver agreement. Conﬁdence intervals were set at 95%(p < 0.05), and tests for signiﬁcant differenceswere performed.

1.2 Imaging evaluation

A total of 10 healthy volunteers [mean age,
29.4 years (25–40 years); 7 males and 3 females] were imaged using the 3D T2 TFE and3D T2 VISTA methods and visually evaluatedfor nerve root delineation ability. None of thevolunteers had symptoms of cervical nerve
root disease. The imaging parameters areshown in Table 1. Two radiologists (with 4 and30 years of diagnostic radiology experience)
independently scored the ability of both methods to visualize the bilateral ﬁrst cervical toﬁrst thoracic nerve roots. The evaluation method was based on a four-point scale, with ascore of 3, 2, 1, and 0 indicating that the cervical nerves from inside the dural sac to outside
the intervertebral foramen could be clearly observed, were partially obscured but observable, were only partially observable, and were
not observable, respectively 16) (Fig.2).

1
2

A

2 Results
2.1 Validation of the 3D T2 TFE sequences

Among the 10 healthy volunteers, signal values at the level of the ﬁfth cervical vertebra
were highest in the bilateral nerve roots andwere signiﬁcantly higher than were signal values in ﬂuid tissues such as the left vertebral
artery and CSF. No signiﬁcant differences insignal values were observed between the left
and right nerve roots or between the left vertebral artery and CSF (Fig.3).
2.2 Image evaluation

The 3D T2 TFE sequences revealed that bilateral nerve roots had a high signal, whereas
blood vessels and CSF had a low signal. Mean-

B

3
4
5
6
7

C
C

D

8
9
10
11

Fig.
Examplesimage
qualityscoringFig.2 2 Examples
of of
image
qualityscoring

MR imaging examples of the 4 grades used for qualitative evaluation of the cervical nerve from the intradural to extraforaminal
regions. The reformatted axial images of the originally acquired 3D T2 TFE image show examples of the following: not visible（score 0; A）, partly visible（score 1; B）, visible（score 2; C）, and clearly visible（score 3; D）
.
13

12
14
15
16

Arts and Sciences ◆ 17

*
2500

*

Signal Intensity

2000

*

*

1500

*

1000

*
*

*

500
0

A

B

C

D

E

＊ : p ＜ 0.001

Fig.3 Signal intensity of various structures in 3D T2 TFE images（A）: right nerve root,（B）: paraspinal muscle,（C）: cerebrospinal ﬂuid,（D）: left vertebral artery,（E）: left nerve root
The average signal value from 10 healthy volunteers was highest in the bilateral nerve roots, which was signiﬁcantly higher
than the average signal values of the other structures.

Fig.4 3D T2 TFE and 3D T2 VISTA images（ A ）3D T2 TFE and 3D T2 VISTA axial reformatted images at the level of C3.
（B）3D T2 TFE and 3D T2 VISTA axial reformatted images at the level of C5.
（C）3D T2 TFE and 3D T2 VISTA oblique sagittal reformatted images.

（A）-（C）Reformatted acquired 3D T2 TFE images demonstrating that the nerve roots and spinal cord have the highest signal intensity within the thecal sac through the extraforaminal region（white arrow）. The structures surrounding the nerve root,

such as blood vessels and CSF, are visualized as areas of low signal intensity. Thus, the 3D T2 TFE sequence provides highcontrast images between the cervical nerve root and surrounding structures. In contrast, the 3D T2 VISTA images show thenerve root and spinal cord as having low signal intensity（open arrow）. Moreover, the extradural region of the cervical nerve
root is not as well visualized as with the 3D T2 TFE sequence.

18 ◆ Journal of JART English edition 2023

original articles
3D T2-weighted turbo field echo (3D T2 TFE) sequences for evaluation of cervical nerve roots

while, the 3D T2 VISTA sequences showed that
the CSF and adipose tissue had a high signal,
whereas the nerve roots had a low signal(Fig.4). The 3D T2 TFE and 3D T2 VISTA images
were obtained from 10 volunteer. Two radiologists evaluated those images according to thevisual scale and gave high mark on 3D T2 TFE
images at the level of 3 to 7 cervical spine (Table 2).

3D T2 TFE sequences, the signal intensity in the
ROI at the level of the ﬁfth cervical vertebra
was signiﬁcantly higher than that of the left
vertebral artery and ﬂuid tissues, such as the
CSF, with the highest signal values observed at
the bilateral nerve roots. Yoneyamaʼs reportstates that to selectively delineate nerves on
MRI, either enhancing the nerves themselves
or suppressing the signal of surrounding tissues can be effective 10). Moreover, we wereable to conﬁrm the difference in signal intensity between cervical nerve roots and surrounding structures with the 3D T2 TFE technique.
Visual evaluation by the radiologist revealed
higher scores at the third to seventh cervicalvertebra levels and signiﬁcantly better nerve
root delineation with the 3D T2 TFE sequences
than with the 3D T2 VISTA sequences. Thismay have been attributed to the ability of the3D T2 TFE sequences to reduce the signal
around the nerve root, such as CSF, bone, andblood vessels, and image the nerve root itself
with a high signal. In contrast, the 3D T2 VISTA
sequences delineates the nerve root itself with

2.3 Statistical image evaluation

The results of statistical analysis of nerve root
delineation performance are shown in Table 2.
In visual score of nerve root delineation, the3D T2 TFE images at the level of the third toseventh cervical vertebrae had signiﬁcantly
higher. The interobserver agreement using
kappa values was 0.68 (0.56–0.80) and 0.34
(0.25–0.52) for the 3D T2 TFE and 3D T2 VISTA
sequences, respectively, with the 3D T2 TFE
sequences showing a greater agreement.

3 Discussion
Among the 10 volunteers imaged using theTable 2 Nerve root scores and Wilcoxon signed-rank test results for each of the two readers
Reader 1
3D T2 TFE

C1
C2
C3
C4
C5
C6
C7
C8
Th1

p-value

3D T2 VISTA

right nerve root（mean ± SD）
left nerve root（mean ± SD）
0.7 ± 0.15
0.1 ± 0.10
0.7 ± 0.15
0.1 ± 0.10
1.3 ± 0.21
2.2 ± 0.29
1.3 ± 0.21
2.2 ± 0.29
2.7 ± 0.15
2.1 ± 0.23
2.7 ± 0.15
2.1 ± 0.23
2.7 ± 0.21
1.8 ± 0.20
2.9 ± 0.10
1.8 ± 0.20
3.0 ± 01.8 ± 0.20
3.0 ± 01.9 ± 0.18
3.0 ± 01.9 ± 0.18
3.0 ± 02.0 ± 0.21
3.0 ± 02.2 ± 0.25
2.9 ± 0.10
2.2 ± 0.25
2.3 ± 0.26
2.4 ± 0.34
2.4 ± 0.34
2.4 ± 0.27
0.6 ± 0.22
2.3 ± 0.26
0.6 ± 0.22
2.0 ± 0.26

Reader 2
3D T2 TFE

0.015
n.s
0.029
0.006
0.004
0.004
0.006
0.016
0.015
n.s
n.s

p-value

3D T2 VISTA

right nerve root（mean ± SD）
left nerve root（mean ± SD）
1.2 ± 0.15
1.1 ± 0.10n.s
1.2 ± 0.15
1.1 ± 0.10
2.4 ± 0.18
1.6 ± 0.24
0.009
2.6 ± 0.18
1.7 ± 0.24
0.015
2.3 ± 0.16
1.8 ± 0.22
0.038
2.2 ± 0.15
1.6 ± 0.24
0.039
2.6 ± 0.18
1.9 ± 0.26
0.03
2.3 ± 0.17
1.8 ± 0.28
2.9 ± 0.10
1.9 ± 0.26
0.009
2.9 ± 0.10
1.9 ± 0.30
3.0 ± 01.8 ± 0.20
0.006
3.0 ± 01.8 ± 0.30
2.9 ± 0.10
2.0 ± 0.29
0.009
2.8 ± 0.15
1.9 ± 0.31
1.9 ± 0.31
2.0 ± 0.24n.s
2.1 ± 0.28
1.9 ± 0.31
1.7 ± 0.29
1.2 ± 0.15n.s
1.9 ± 0.31
1.3 ± 0.17
n.s. : not signiﬁcantArts and Sciences ◆ 19

a low signal. Therefore, while T2 contrast between the CSF and nerve root allows us to observe the nerve root run in the spinal canal
where CSF exists, the contrast decreases outside the spinal canal where the CSF signal disappears, and the visibility of the nerve root
becomes poor, making it difﬁcult to adequately
follow the run of the nerve root. However, outside the spinal canal, where the CSF signal islost, the contrast is reduced, leading to the presumption that the nerve roots could not be adequately followed due to poor visibility 8). Previous studies have shown that diagnostic imaging of cervical spondylotic nerve root diseaserequires high-resolution imaging using the 3D
method with thin slices and no gaps between
slices 6). This studyʼs investigation of 3D T2 TFE
sequences has demonstrated the ability to reconstruct images in any cross-section and produce high-contrast imaging of the spinal cord.
As a result, there is potential for improved depiction of nerve root compression in cervicalspondylotic nerve root disease, speciﬁcally fornerve roots outside the intervertebral foramen.
The 3D T2 TFE sequences was not superior
to the 3D T2 VISTA sequences for the eighth
cervical vertebra and ﬁrst thoracic vertebra
nerve root. This may have been due to the inﬂuence of magnetic susceptibility caused by
the lungs, phase dispersion caused by respiration and body movement, and signal degradation caused by coil geometry. The T2 TFE sequences used in the current study is a GRE
method that collects SE signals, and gradientspoiling is performed immediately after RF to
reduce the signal of the FID component 17).
Moreover, although the multi-shot method cuts
off the steady state once and collects data, allowing for further reduction in the signal of
ﬂowing tissues, such as the CSF and blood vessels, the effects of body movement and respiration are reﬂected sensitively, for which we
assume the absence of a signiﬁcant differenceat the level of the eighth cervical vertebra or
ﬁrst thoracic vertebra. Since the preferred site

20 ◆ Journal of JART English edition 2023

of cervical radiculopathy is at the level of the
4th to 7th cervical nerve roots, we believe that
3D T2 TFE may be useful in most cases for the
diagnosis of cervical radiculopathy, even if theﬁndings of the 8th cervical nerve root or the 1st
thoracic nerve root are not signiﬁcantly better
than the 3D T2 VISTA sequences.
The 3D T2 TFE sequences displayed a higher
interobserver agreement rate than did the 3D
T2 VISTA sequences, perhaps due to its theability to image the nerve roots themselves
running from the spinal cord into and out of
the intervertebral foramen with high contrast.
Conversely, evaluating the entire nerve root
running from the spinal cord to outside the intervertebral foramen using the 3D T2 VISTA sequences proves quite difﬁcult, which may have
reduced the interobserver agreement rate 18), 19).
One limitation of this study is that our study
population comprised healthy volunteers andnot on patients with cervical spine disease. Future studies will be needed to examine whether nerve root symptoms coincide with the stenosis site in patients with clinical symptoms.

4 Conclusion
The 3D T2 TFE sequences and the 3D T2 VISTA sequences, which allows for a freely reconstructable 3D sequence for cervical nerve root
delineation, were examined for their ability todelineate nerve roots. Our ﬁndings showedthat the 3D T2 TFE sequences was able to delineate nerve roots by presenting them as a signiﬁcantly higher signal compared to the surrounding structures. Moreover, the 3D T2 TFE
sequences was signiﬁcantly more effective at
the level of the third to seventh cervical vertebrae, from within the spinal canal to outside
the intervertebral foramen, than was the 3D T2
VISTA sequences while showing with a highinterobserver agreement rate. We believe that
this method will be widely used as a standard
imaging technique for nerve root evaluation
during cervical spine MRI in the near future.

original articles
3D T2-weighted turbo field echo (3D T2 TFE) sequences for evaluation of cervical nerve roots

Conflicts of interest

We have no conﬂicts of interest to disclose inthis study.
Acknowledgments

We would like to express our deepest grati-

References
1） Hiroki Shishido, et al.: Visualization of the Foramen
Intervertebral Nerve Root of Cervical Spine with 3.0
Tesla Magnetic Resonance Imaging: A Comparison ofThree-dimensional Acquisition Techniques. Japanese
Journal of Radiological Technology, 70(7), 670-675,
2014 (in Japanese).
2） Park HJ, et al.: A practical MRI grading system for
cervical foraminal stenosis based on oblique sagittal
images. Br J Radiol, 86(1025), 20120515, 2013.
3） Park HJ, et al.: The clinical correlation of a newpractical MRI method for grading cervical neuralforaminal stenosis based on oblique sagittal images.
AJR, 203(2), 412-417, 2014.
4） Park HJ, et al.: Clinical correlation of a new practical
MRI method for assessing cervical spinal canalcompression. AJR, 199: 197-201, 2012.
5） Naoyasu Okamura, et al.: Evaluation of Cervical
Spine Lesions by the 3D T2-SPACE Compared withthe 2D T2WI. Spinal Surgery, 34(1), 59-65, 2020 (inJapanese).
6） Chikage Inukai, et al.: Usefulness of Curved
Coronal MPR Imaging for the Diagnosis of Cervical
Radiculopathy. Neurological Surgery, 38(3), 251-257,
2010 (in Japanese).
7） Hisanobu Koga, et al.: 3.0T MR Imaging of the
Cervical Nerve Root in the Intervertebral Foramen.
Spinal Surgery, 22(2), 80-85, 2008 (in Japanese).
8） Kwon JW, et al.: Three-dimensional isotropic T2weighted cervical MRI at 3T: Comparison with
two-dimensional T2-weighted sequences. ClinicalRadiology, 67, 106-113, 2012.
9） Syuji Okinaga, et al.: Delineation of brachial plexus
disease by diffusion-weighted MRI. The journal ofJapanese Society for Surgery of the Hand, 26(6), 616621, 2010 (in Japanese).

tude to the members of the Imaging Center for
their guidance in this study.
A part of this paper was presented at the45th Annual Meeting of the Japanese Society
for Magnetic Resonance Medicine in Utsunomiya, Japan.

10）Masami yoneyama: MR Neurography: Novel MR
Imaging Techniques for Depiction of Peripheral
Nerves. Neurological Therapeutics, 32(2), 201-204,
2015 (in Japanese).
11）Tsuchiya K, et al.: Visualization of cervical nerve roots
and their distal nerve fibers by diffusion-weighted
scanning using parallel imaging. Acta Radiol, 47, 599602, 2006.
12）Masami Yoneyama, et al.: Rapid High Resolution MR
Neurography with a Diffusion-weighted Pre-pulse.
Magn Reson Med, 12, 111-119, 2013.
13）Masami Yoneyama, et al.: Reevaluation of T2weighted fast ﬁeld echo (T2FFE): application to rapid
volumetric black-blood imaging. Radiol phys Technol,
6(2), 305-312, 2013.
14）Marielle E.P. Philippens, et al.: TRACING THE
CRANIAL NERVE PATHWAYS NV AND NVII WITH 3D
T2-FFE. Mag. Reson. Med, 20, 1059, 2012.
15）Osamu Uchida, et al.: Medical Data Analysis with
JMP. Tokyotosho, 96-99, 2012 (in Japanese).
16）Masahiro Miura，et al.: Latest ﬁndings in cerebrospinal
fluid. Spine & spinal cord, 28(8), 694-703, 2015 (inJapanese).
17）M a s a m i Yo n e y a m a , e t a l . : D i ff e re n t i a t i o n o fhypointense nodules on gadoxetic acid-enhanced
hepatobiliary-phase MRI using T2 enhanced spinecho imaging with the time-reversed gradient echo
sequence: An initial experience. EJR, 95, 325-331,
2017.
18）Harold L Kundel, et al.: Measurement of Observer
Agreement. Radiology, 228, 303-308, 2003.
19）Hiroshi Nishiura: A Robust Statistic AC1 for Assessing
Inter-observer Agreement in Reliability Studies.
Japanese Journal of Radiological Technology, 66(11),1485-1491, 2010 (in Japanese).

Arts and Sciences ◆ 21

Arts and Sciences
original articles

Received June 2, 2021 ; accepted November 25, 2021

Dosimetry with a custom-made chest radiography
dosimeter and radiation dose management fromthe analysis results
SHINKAI Eishu1）, OOISHI Tetsuya1）, TAKAGI Yuu1）, KATOU Hiroaki1）, KOMIYA Hiroko1）,
UEDA Kouki1）, YOSHIKAWA Kumiko1）, RIKITAKE Sayaka1）, BABA Ikuko2）
1）Roueiken Medical Check Center, Fukuoka Institute of Occupational Health, Radiological Technologist
2）Roueiken Medical Check Center, Fukuoka Institute of Occupational Health, Doctor

Note: This paper is secondary publication, the ﬁrst paper was published in the JART, vol. 69 no. 835: 39-44, 2022.
Key words: chest radiography, radiation dose management, incident surface dose, body weight【Abstract】

Chest radiographs in medical examinations usually involve many examinees of different body types. In this study, amethod for estimating the exposure dose for each examinee was determined.
First, we made our own radiation dosimeter for chest radiography of the examinee, installed it in one of the chest
radiography rooms, conﬁrmed that it could measure with high accuracy, and analyzed the measurement data.
The measured data showed, that the exposure dose correlated well with the weight of the examinee. Therefore, therelationship between the weight of the examinee and his/her exposure dose can be applied for the exposure dosemanagement of the examinee, even in other chest imaging rooms.

1. Introduction
The diagnostic reference levels (DRLs) thatwere ﬁrst introduced in June 2015 speciﬁedthat the incident surface dose to the frontal
chest was 0.3 mGy. Subsequently, the DRLs
were revised in July 2020 (DRLs 2020), and a
new item for the frontal surface of the chest at
the time of medical examination was added
separately from the frontal surface of the chestand set at 0.2 mGy.
Our institution conducts both facility and traveling medical checkups, and more than 340,000
individual underwent chest imaging in 2019.
The large number of people who undergo chest
imaging has resulted in a large population effective dose. Thus, we keenly felt the need to
manage the dose in examinees during healthexaminations. We then attempted to manage
the dose of the examinees in the chest imaging,including the optimization by DRLs 2020.
In the past, lung ﬁeld phantoms (standard
body shape) were usually taken in using a

22 ◆ Journal of JART English edition 2023

phototimer in all chest imaging equipment.
The values of the examineeʼs exposure dose
under those imaging conditions were posted ineach imaging room. However, estimating theradiation doses of many examinees with different body shapes is difﬁcult; therefore, a custom-made dosimeter was installed in one of
the chest radiography rooms. We evaluated thecharacteristics of the dosimeter, conﬁrmed thatit can measure doses with high accuracy, analyzed the measured data, and developed a simple method for estimating the chest doses ofeach examinee.

2. Materials and methods
2.1 Overview of the custom-made dosimeterfor chest radiography

A dosimeter for chest radiography was developed because a custom-made dosimeter hascomparable performance to commercially available dosimeters 1) and can be manufactured inexpensively (less than 100,000 yen).

original articles
Dosimetry with a custom-made chest radiography dosimeter and radiation dose management from the analysis results

2.1.1 Ionization chamber

2.1.2 Ampliﬁer

Considering the size of the front face of the
movable aperture, the ionization chamber 2) issquare, with 180 × 180 mm in external dimension and 146 × 146 mm in internal dimension.
The frame was made by cutting out a 4-mm
thick brass plate. The electrodes were of parallel-plate type and consisted of two layers: current-collecting and high-voltage electrodes.
The walls were made of two layers of 100-μmthick polyester ﬁlm stretched over the frame at
4-mm intervals. The collector electrode wasformed on the upper layer and the high-voltage electrode on the lower layer, using 15-μmthick aluminum (household aluminum foil,
99.4% purity) and bonded together. The areaof the collector electrodes was 20 × 20 mm,
and that of the high-voltage electrodes was 30
× 30 mm.
Fig.1 shows an illustration of the cross sectionof an ionization chamber, and Fig.2 shows theactual appearance of the ionization chamber.

The ampliﬁer was the same in principle ascommonly used ampliﬁers; however, a Model
AD549KH (Analog Devices) was used as the
direct current ampliﬁer. The ionizing charge at
the time of X-ray irradiation was charged to acapacitor of 0.016 μF, and the amount ofcharge was converted to the absorbed dose at
the skin surface of the examinee (20 cm fromthe top of the imaging plate) and displayed.
The indicated value was obtained by calibrating the custom-made ionization chamber dosimeter (Roueiken type) 3) with Accu Dose+10X6(Radcal Corporation), measuring the dose
(μC/kg) at the target position, and multiplying
the backscatter coefﬁcient and absorbed doseconversion factor to obtain the incident surface
absorbed dose. To achieve this value, the adjustment resistor shown in Fig.3 was used todisplay the value in mGy.
A DC voltage of 200 V was applied to thehigh-voltage electrode using a high-voltage
module (Bellnix Co., Ltd.).

Fig.1 Illustration of the cross section of an
ionization chamber

Fig.3 Principle of the measuring circuit of anamplifierFig.2 Actual appearance of the ionization chamber

Fig.4 Actual appearance of the amplifier
Arts and Sciences ◆ 23

Fig.3 shows the principle for measuring thecircuit of an ampliﬁer, and Fig.4 shows the actual appearance of the ampliﬁer.
2.2 Characterization of the custom-made dosimeter for chest radiography
The following equipment and materials wereused to characterize the custom-made dosimeter for chest radiography: high-voltage X-ray
equipment, HITACHI DHF-153H4R (Radnext)(total ﬁltration 2.5 mm Al); and digital photography equipment, FUJI FILM DR-ID1200 (CALNEO Smart).
Dose ratios were obtained using the custommade ionization chamber dosimeter (Roueikentype) 3) as a reference dosimeter.
2.2.1 Beam quality characteristics

The radiation quality characteristics of thecustom-made dosimeter for chest radiography
were measured at 80, 100, 120, and 130 kV
tube voltages. The irradiation ﬁeld was 43 ×
43 cm on the imaging tabletop. The ionizationchamber of the chest radiography dosimeter
was mounted in front of the movable aperture,and the custom-made ionization chamber dosimeter (Roueiken type) 3) was simultaneously
measured at 179 cm, 20 cm away from the thoracic imaging tabletop.
2.2.2 Dose-rate characteristics

The dose rate characteristics of the custom-Fig.5 Schematic diagram of the layout

24 ◆ Journal of JART English edition 2023

made dosimeter for chest radiography were
measured at a tube voltage of 120 kV in thesame arrangement as for the measurement of
the beam quality characteristics. The dose rateis deﬁned as the dose rate at the incident planeof the skin.
2.3 Clinical application of the custom-madedosimeter for chest radiography
2.3.1 Dosimetry by chest radiography dosimeters in health examinations

A schematic diagram of the arrangement isshown in Fig.5. The incident surface dose wasmeasured at a chest thickness of 20 cm fromthe imaging top plate using an ionizationchamber in front of the movable aperture andis indicated in units of absorbed dose (mGy).
This dosimeter for chest imaging is used indaily health checkups, and the absorbed dosevalues are currently recorded manually.
2.3.2 Analysis of exposure doses in medical examinations

The frequency of absorbed doses during
medical examinations is shown in Fig.6. The
male-female total and female mode are 0.18
mGy., while the mode for males was 0.22 mGy,
which is approximately 22% higher. The median and mean for males and females combined are 0.23 and 0.25 mGy, respectively.
The relationship between the absorbed doseat the incident surface location and height,
weight, abdominal circumference, and bodymass index (BMI) was determined for the combined male and female data.
The correlation coefﬁcient between absorbed
dose and height was 0.3671, with correlation
coefﬁcients of 0.8349 for weight, 0.7882 for abdominal circumference, and 0.8386 for BMI.
The correlation was weak for height but strong
for BMI, weight, and abdominal circumference.
Particularly, the correlation coefﬁcients between BMI and weight wear close to 1.0, indicating a strong correlation.
However, since BMI is calculated through theoriginal articles
Dosimetry with a custom-made chest radiography dosimeter and radiation dose management from the analysis results

Fig.6 Frequency of the absorbed dose

Fig.7 Relationship between the body weight and absorbed dose at the time of chest radiography

formula weight in kg / (height in m) 2, weight iseasier to use; thus, weight was used for dose
control in the other chest radiography rooms.
Fig.7 shows the relationship between bodyweight and absorbed dose.

Fig.8 The box-and-whisker diagram

2.4 Dose control in other chest radiography
rooms

The doses were measured using the custommade dosimeter for chest radiography. The absorbed doses for the 1,273 male and female
participants were statistically processed to produce box-and-whisker diagrams 4) as shown in
Fig.8.
The lower part of the box had a 25th percentile tile value of 0.19 mGy. The upper part ofthe box has a 75th percentile tile value of 0.29
mGy. The median is 0.23 mGy, and the meanis 0.25 mGy. The lower “whiskers” are 0.12
mGy, and the upper “whiskers” are 0.43 mGy.
Therefore, the dose frequency is shown in
Fig.9, using the dose frequency calculated by
excluding the outliers in Fig.8 from the aforementioned dose frequency in Fig.6.
Fig.9 shows a median value of 0.23 mGy andArts and Sciences ◆ 25

mean value of 0.24 mGy.
The difference between the median andmean values was small, and dose control was
performed by assuming a normal distribution.
For dose control in the other chest radiography rooms, a lung ﬁeld phantom (PBU-SS-2.
Kyoto Scientiﬁc) was used under clinical conditions with a phototimer. The irradiation dose
(μC/kg) under those imaging conditions wasmeasured using the custom-made ionizationchamber dosimeter (Roueiken type) 3) and multiplied by the backscatter coefﬁcient and absorbed dose conversion coefﬁcient to obtain theabsorbed dose (mGy) at the incident surface
position for 25 chest imaging rooms (vehiclemounted: 22 rooms, facility-mounted: 3 rooms)(computed radiography [CR]: 2 rooms, ﬂat panel
detector [FPD]: 23 rooms). The absorbed doses
ranged from 0.13 to 0.23 mGy.

3. Results
3.1 Overview of the custom-made dosimeterfor chest radiography

The electrode in the center was covered withaluminum foil, which blocked the light-illuminated ﬁeld. However, the area around it wasmade of polyester ﬁlm; hence, taking pictures
without any difﬁculty in positioning is possible.
3.2 Characterization of the custom-made dosimeter for chest radiography
3.2.1 Beam quality characteristics results

The measurement results at 80 to 130 kV areshown in Fig.10. The beam quality dependence is in the range +8% to -5%. Since chest
imaging is almost exclusively performed at 120
kV, it can be said that there was no error.
3.2.2 Dose rate characteristic results

The results of measurements at dose rates
from 144 to 300 (µC/kg)/s are shown in Fig.
11. The dose rate dependence is within -3%.
In chest imaging, dose control is possible
with minimal dose quality or dose rate dependence.
3.3 Clinical application of the custom-madedosimeter for chest radiography

Since the correlation coefﬁcient between theFig.9 Frequency of the absorbed dose

Fig.10 Beam quality dependence of an ionizationchamber

26 ◆ Journal of JART English edition 2023

Fig.11 Dose rate dependence of an ionizationchamberoriginal articles
Dosimetry with a custom-made chest radiography dosimeter and radiation dose management from the analysis results

absorbed dose and body weight for 1,273 maleand female participants, whose data were taken with the custom-made dosimeter for chest
radiography, showed a strong correlation, bodyweight was used to control doses in other chest
radiography rooms.
3.4 Dose control in other chest radiography
rooms

The regression equation between body weight
and absorbed dose (y = 0.0049x - 0.061) in Fig.
7 was used for dose control in the other chest
imaging rooms.
In the normal distribution, when the mean

Fig.12 Relationship between the body weight andabsorbed dose

Fig.13value is represented as μ and standard deviation as σ, 68.27% of the values are included inthe μ ± σ range. Therefore, the absorbed dose
calculated by the regression equation is represented by one line in the middle and the σrange (± 34%) by two lines. Fig.12 shows anexample of the dose notation in another chest
radiography room (absorbed dose: 0.15 mGy,
vehicle-mounted type: FPD).
An example of a posting board in anotherchest radiography room (absorbed dose: 0.15
mGy, vehicle-mounted type: FPD) is shown in
Fig.13. The notice was mounted next to theradiation room such that the radiation dose canbe estimated based on body weight.
Examples of dose notations and postings for0.15 mGy are shown here, but similar dose notations were used for all 25 chest radiographyrooms with absorbed doses between 0.13 and0.23 mGy, and postings were installed.
In addition, there were initially three rooms(0.23, 0.27, and 0.21 mGy) with equipment thatexceeded the DRLs 2020 examination chest
frontal incident surface dose of 0.2 mGy. Thelung ﬁeld phantoms were taken under reduced
imaging conditions, and the images were eval-

Postings for radiation dose control
Arts and Sciences ◆ 27

uated by one doctor and six radiologists. Tworooms (0.27 mGy to 0.23 mGy and 0.21 mGy to
0.19 mGy) were able to reduce the dose.
Two rooms (0.23 mGy: two rooms) had
equipment that exceeded 0.2 mGy of the DRLs
2020 examination chest frontal incident surface
dose; however, all were vehicle-mounted andhad been installed for 16 years, and the digital
imaging equipment was CR equipment.

4. Considerations
In medical examinations, chest radiographyrequires the imaging of many examinees in ashort period of time, and there is often insufﬁcient time to consider individual exposure doses. Although installing dosimeters in all chest
radiography equipment is desirable, it is difﬁcult to do so in terms of cost and time. We also
compared the results of computer software calculations and showed that they wear 10-20%
lower.
Therefore, we used a simple method to estimate the absorbed dose at the incident surface
location based on the body weight, which isstrongly correlated with the absorbed dose of
the examinee. A strong correlation between
BMI and incident surface dose on chest radiography was observed 5). It has also been reported that there was a strong correlation between
BMI and incident surface dose in gastric radiography 6).
We also found similar results regarding thestrong correlation with BMI and a similarly
strong correlation with body weight; therefore,
we decided to use the participantʼs weight foreasier management.

5. Conclusion
A custom-made dosimeter for chest radiography was fabricated to control the exposure
doses during chest radiography in health examinations in which many examinees wear examined.

28 ◆ Journal of JART English edition 2023

The characteristics of the system were also
conﬁrmed to maintain sufﬁcient accuracy, andthe radiation dose during chest imaging wasmeasured in a clinical setting. By analyzing
and statistically processing the measurement
results, a bulletin board was posted in eachchest imaging room to enable the estimation of
the dose from the weight of the examinee inthe other chest imaging rooms. This enabled
us to conﬁrm the estimated doses of the examinees and establish a system to appropriately
respond to inquiries from examinees regarding
radiation exposure by providing them with theestimated doses and a separately prepared
medical exposure Q&A (radiation exposureand effects on the human body, etc.).

Acknowledgements
We thank Prof. Toshioh Fujibuchi of the Department of Health Science, Faculty of Medical
Sciences, Kyushu University for his guidance incalibrating the custom-made dosimeter. We
also thank the members of the Department ofRadiology, Department of Medical Technology, Kyushu University Hospital for allowing us
to borrow the lung ﬁeld phantom.
We would like to thank Editage (www.editage.
com) for English language editing.

Ethics statement
Although we believe that this study needs tobe reviewed by an ethics review committee because it includes the radiation dose, height,
weight, abdominal circumference, and BMI ofthe examinees, our facility does not have an
ethics review committee. Therefore, we consulted the “Medical Ethics Review Committee”
of the Japanese Association of RadiologicalTechnologists and conducted a full exchangeof views with the facility manager (director).
The study was then conducted based on the
stipulation of the “Privacy Policy” of the facilityʼs website such as the use of anonymous dataoriginal articles
Dosimetry with a custom-made chest radiography dosimeter and radiation dose management from the analysis results

as sample data, including conference presentations, and obtaining the consent of the examinees on the examination forms.

Conﬂicts of interest
There are no conﬂicts of interest to disclosewith respect to this study.

References
1） Eishu Shinkai: Patient dose control in X-ray examination. Japanese Journal of Radiological Technology,
Vol.57, No.4, 377-387, 2001.

2） Eishu Shinkai, et al.: Property evaluation of newly developed patient double electrode ionization chamber
for measuring patient exposure. Japanese Journalof Radiological Technology, Vol.52, No.5, 639-644,
1996.
3） Eishu Shinkai, et al.: Dosimetry in medical examinations - Characterisation of a custom-made ionizationchamber dosimeter (Roueiken type) -. Annual meeting
abstracts of the Kyushu Radiological Medical Technology, 109, 2012.
4） Hiroshi Hayama: Textbook of statistics for data analysis. Impress Co., Ltd, 1-252, 2018.
5） Yasuki Asada, et al.: BMI and incident surface doseanalysis in general radiography. Japanese Societyof Radiological Technology General Conference Abstracts, 2005.
6） Yoichi Ohta, et al.: Basic study of dosimetry in gastric
X-ray examinations for lifestyle-related health checkups. Journal of Gastrointestinal Cancer Screening,
Vol.58, No.2, 83-92, 2020.

Arts and Sciences ◆ 29

Arts and Sciences
original articles

Received June 24, 2021 ; accepted February 15, 2022

Content analysis in the proceedings “Study Groupon the Appropriate Management of Medical
Radiation”
SAITO Hiroki，TOKUSHIGE Yumiko，MARUYAMA Sho，IWAI Tsugunori，
KATOU Hideki，HOSHINO Syuhei
Gunma Paz University School of Radiological Sciences, Faculty of Medical Science and Technology

Note: This paper is secondary publication, the ﬁrst paper was published in the JART, vol. 69 no. 837: 21-27, 2022.
Key words: Dose control, minutes, text mining, cluster analysis, correspondence analysis【Abstract】

In April 2020, a ministerial ordinance was enforced to partially revise the Medical Care Act Enforcement Regulations.
The amendment stipulates that the facility manager assigns a person in charge of the safety management system
related to radiation medical care, formulates guidelines, trains staff, and manages and records patient doses. The
Ministry of Health, Labor and Welfare (MHLW) has established the “Study Group on the Appropriate Management ofMedical Radiation” and the minutes of the meeting are available as text data on the MHLW website.
In this study, the minutes of the review meeting were subjected to content analysis (cluster analysis andcorrespondence analysis) using KHcoder3. In the cluster analysis, 10 clusters were set up so that the keywords ofthe ministerial amendment, “record,” “training,” and “responsibility,” would not be in the same cluster. Each Cluster
appeared depending on the number of meetings. Each Cluster appeared depending on the number of meetings.
Correspondence analysis was conducted on “record” and “responsibility” to clarify their relationship with other “words”.
The “record” was to facilitate the UNSCEAR Global Survey, and the “responsibility” was to promote the WHO/IAEA
International Plan of Action on Patient Protection.
In this study group, the relevant laws and regulations were explained in the 1st meeting, the necessity of doserecording and the subjects of training in the safety management system were discussed in the 3rd, 4th, and 5th
meetings, and the 6th, 7th, and 8th meetings. Regarding the guidelines for the safety management system, the rules
regarding the person in charge, records, training, etc. were discussed.

1. Introduction
In April 2020, a ministerial ordinance partially amending the Ordinance for Enforcement of
the Medical Care Act went into effect (Ordinance of the Ministry of Health, Labor and Welfare, (MHLW), No. 21 of 2019) 1). This ordinanceindicated that the medical facility administrator
is responsible for the safety management system related to radiological treatment, and required to establish guidelines, provide staff
training, and control and record patient doses.
To date, radiation control to reduce radiation
doses to the general public and workers has
implied the use of radiation protection standards in facilities and structures and dose limits
for those entering them in accordance with theMedical Service Act and related laws/ordinanc-

30 ◆ Journal of JART English edition 2023

es. In contrast, the medical exposure to patients has not been controlled through dose
limits even if X-ray examinations are performedat the lowest possible dose according to theInternational Commission on Radiological Protection (ICRP) “as low as reasonably achievable” principle 2). These trends in radiation protection are based on the research of the United
Nations Scientiﬁc Committee on the Effects ofAtomic Radiation (UNSCEAR), the ICRPʼs recommendations on radiation protection, and theInternational Atomic Energy Agency (IAEA)ʼs
guidelines. In particular, the IAEA compiled
these recommendations into safety principles,
requirements, and guidelines, which havebeen incorporated into the legal systems ofvarious countries 3). This has enabled us to implement radiation control in accordance with

original articles
Content analysis in the proceedings “Study Group on the Appropriate Management of Medical Radiation”

international standards. The revision follows
the same trend, and in April 2017, the MHLW
launched the “Study Group on the Proper Management of Medical Radiation” and after eight
meetings, the ministerial ordinance was revised 4). However, there is little information on
this revision of the ministerial ordinance, justan introduction to dose management software 5)
and a preface by Yonekura 6). Fortunately, theminutes of the study meeting are available astext data on the MHLW website.
Content analysis using text data has beenlong applied in research 7, 8). Further, the widespread use of analysis software, such as KHcoder3 9), has allowed quantitative text data
analysis. For instance, in sociology, Watabeʼscase study of hierarchical cluster analysis 10) andKuwahataʼs case study of co-occurrence network analysis 11) used KHcoder3 and data fromthe proceedings of the Diet. In the ﬁeld of radiology, Tokushige et al. reported a quantitative
analysis of a questionnaire survey of medical
radiology technician training schools 12).
This study aimed to clarify the process leading to the establishment of patient dose records
and safety management systems by text analyzing the minutes of the review meeting using
KHcoder3.

2. Materials and Methods
A KHcoder3 Windows version including
ChaSen (WinCha 2000 R2), MySQL 5.6, Perl
5.14, R 3.1, and ggplot2 2.1 13) was used foranalysis.
2.1 Preprocessing of text data

The minutes (.docx) of the 1st through 8th
meetings of the “Study Group on the Proper
Management of Medical Radiation” were downloaded from the MHLW website. At the beginning of each meeting, the secretary introduces
the attendees; then, the chairperson gives their
opening statement, followed by the explanation of materials by the secretary, and a ques-tion-and-answer (Q&A) session. Only theagenda items related to this proper management were subjected to text mining. Text data
was created in Excel format (.xlsx).
The agenda is marked by the speaker, followed by what was said. The ﬁrst line of the
Excel worksheet had a header including<Text>, <Part>, and <Chapter>, and the agenda item was entered on the second line. The
actual proceedings were entered in <Text>, thenumbers in <Part>, the secretaryʼs explanation
as “1,” and the Q&A as “2” in <Chapter>; theChairʼs greeting was omitted. As the second
agenda item was just a title change, it was excluded from this analysis. Next, a KHcoder3
project was registered and <preprocessing>
was performed to check the text data.
As both “Diagnostic Reference Levels (DRL)”
and “diagnostic reference level” were found in
the minutes, to detect them as a single term, we
speciﬁed both in <Select Terms> and performed<Preprocessing> and <Execute Preprocessing>.
Then, the program z1_edit_words3.pm (https://github.com/ko-ichi-h/khcoder/issues/101),
which absorbs the two terms, was installed in
the Plugin_jp folder and <plugin> and <distortion of notation> were executed.
This way, we obtained the number of sentences and paragraphs to be analyzed, the extracted words, and their frequency.
2.2 Cluster analysis

Cluster analysis was performed to conﬁrm
the pattern of occurrence of the extracted
words and phrases. KHcoder3 uses a <Hierarchical Cluster Analysis> as default, but to consider the location information of words withsmall number of occurrences 14), a csv data ﬁlewas created using <export> and <“extracted
words x context vector” table>. For the extraction, the minimum number of occurrences was
set to 55 (default value), csv data was output,
R was initiated to read the csv data, and hierarchical cluster analysis was performed using thehclust function. The distance between clusters
Arts and Sciences ◆ 31

was speciﬁed as ward.D2.
2.3 Bubble plots for meeting number and eachcluster

Coding rules were developed to check thefrequency of occurrence of the extracted words
in each cluster of the meeting numbers. The
words extracted in each cluster speciﬁed in the
text data (.txt) are shown in Table 1. Finally, abubble plot of meeting numbers and clusters
was created based on the cross-tabulation table (<Tools>, <Coding>, and <Cross-tabulationtable>).
2.4 Correspondence analysis of the characteristic words “record” and “responsibility”

In terms of proper management, the key
points of the revision of the ministerial ordinance are the recording of patient doses andthe establishment of a safety management system. In 3.1, “record” is included in Cluster 1
and “responsibility” in Cluster 10. In 3.2, Cluster 1 appeared at high frequency in the 3rd,
4th, and 5th times, and Cluster 10 in the 6th,
7th, and 8th times. Therefore, a correspondence analysis was conducted to conﬁrm theTable 1 Coding rules
Cluster

relationship between these words and meeting
number. Texts of the 3rd, 4th, and 5th meetings
containing “record” were extracted from thetext data of the minutes and a correspondence
analysis (<tool>, <extracted word>, <correspondence analysis>) was performed setting
the minimum number of occurrences to 5 (default value). Similarly, texts from the 6th, 7th,
and 8th meetings containing “responsibility”
were extracted and analyzed for correspondence.

3. Results
3.1 Preprocessing and cluster analysis

After preprocessing, there were 1,890 sentences, 907 paragraphs, and 76,829 total extracted words (e.g., medical: 587 occurrences,
radiation: 478). Figure 1 shows the results ofthe cluster analysis. Words found near eachother in a sentence formed a hierarchy. As thenumber of clusters can be determined arbitrarily, to avoid that the keywords “record,” “training,” and “responsibility” of the revised ministerial ordinance were all clustered together, wedeﬁned 10 clusters with a height of 2.68 (seeTable 1). The number of extracted words were6, 18, 6, 9, 15, 5, 3, 7, 2, and 4 for Clusters 1–10,
respectively (Fig.1).

Words

1

examination, CT, dose, record, exposure,appropriate

2

actual, patient, receive, use, just now, need,say, extremely, now, think, see, problem,
appear, impact, data, year, Japan, DRL

3

concrete, correspondence, case, protection,
standard, deﬁne

4

future, study, discussion, administrative, teacher,
opinion, page, documents, explanation

5

optimum, justiﬁable, training, implementation,
partial, basic, consider, at this time, form,
viewpoint, each, regulation, do, radiation,
medical treatment

6

facilities, hospital, equipment, medical,
institutions

7

treatment, devices, irradiation

8

pharmaceuticals, radiation, target, RI, hazard,
regulatory, relation9

doctor, technologist

10

responsibility, system, management, safety

32 ◆ Journal of JART English edition 2023

3.2 Bubble plots for meeting number and eachclusterTable 2 shows a cross table of which meet-ings the Clusters containing the words createdby the coding rules appeared in. χ2 represents
the χ2 test result, with p<0.05 indicating thethreshold for signiﬁcance. Figure 2 shows thepercentage of each cluster in each meeting
based on this cross-tabulation table. The percentage of occurrence was calculated by dividing the frequency in each meeting number by
the total number of occurrences (e.g., 51/252
for Cluster 1) and is shown as the square size.
The colors represent standardized residuals:
Pearson rsd ( mean × (frequency - mean)/original articles
Content analysis in the proceedings “Study Group on the Appropriate Management of Medical Radiation”

examination (156)CT (91)
dose (353)
record (120)exposure (300)appropriate (70)
actual (72)patient (190)receive (72)use (67)
just now (71)need (119)say (61)
extremely (72)
now (145)
think (446)see (59)
problem (57)
appear (63)
impact (65)data (55)year (65)Japan (90)
DRL (103)
concrete (60)correspondence (87)case (99)protection (90)standard (90)deﬁne (57)
future (63)study (112)
discussion(80)administrative (65)
teacher (81)opinion (143)page (104)documents (61)explanation (102)
optimum (109)justiﬁable (94)training (110)implementation (56)partial (111)
basic (72)consider (244)
at this time (70)form (206)viewpoint (67)each (61)regulation (57)
do (154)
radiation (478)medical treatment (227)
facilities (81)hospital (103)equipment (105)
medical (587)
institutions (119)treatment (69)
devices (105)
irradiation (55)
pharmaceuticals (67)radiation (85)target (58)
RI (65)hazard (59)regulatory (70)relation (56)doctor (90)technologist (66)
responsibility (65)system (57)
management (340)safety (239)Fig. 1 Custer analysis

Fig.1 Cluster analysis

and 7th meetings for Cluster 5. Cluster 3 appeared predominantly in the 7th meeting, although not so often, and showed large standardized residuals. Cluster 4 and 6 were moderately frequent but tended to appear in the
6th and 7th meetings. Cluster 7 and 8 did notoccur often, but had large ﬁrst standardized residuals. Cluster 9 and 10 did not occur very
often, but showed large standardized residuals
for the 6th, 7th, and 8th meetings.

mean value), indicating the meeting in which
the cluster appears more (or less) often, withwarmer colors indicating more frequent appearance. The mean value corresponds to thenumber of current entries relative to the total
number of sentences.
Cluster 1 appeared frequently in the 3rd, 4th,and 5th meetings, showing large standardized
residuals. Clusters 2 and 5 often appeared in all
meetings; standardized residuals were positivein the 3rd meeting for Cluster 2 and in the 6th

Table 2 Cross-accumulation table of number of meetings held and clusters
Cluster

Meeting
Number

1

2

3

4

5

6

7

8

9

10

1

51

149

81

108

143

104

51

95

5

63

252

3

59

93

33

39

60

46

13

9

3

5

106

4

63

79

24

51

68

47

9

12

3

28

99

5

90

115

35

52

97

56

16

9

4

24

146

6

34

89

30

66

99

70

10

26

20

59

123

7

43

68

46

56

78

46

10

18

16

33

93

n

8

17

47

19

37

60

31

4

30

15

37

88

sum

357

640

268

409

605

400

113

199

66

249

907

χ2

128.95

52.66

26.43

22.97

39.25

15.34

22.73

82.52

61.41

75.61

p<0.05

6.94E-30 3.97E-13 2.74E-07 1.65E-06 3.73E-10 9.00E-05 1.86E-06 1.05E-19 4.63E-15 3.45E-18

Arts and Sciences ◆ 33

monly appeared. From the beginning, there
were characteristic words such as “Japan,”“IAEA,” and “difﬁcult” in the 3rd meeting, “hospital,” “on-site,” and “burden” in the 4th meeting, and “EU,” “appropriate,” and “training” in
the 5th meeting. Several words followed a linear distribution between the third “IAEA” to thefourth “hospital,” the fourth to the ﬁfth “training,” and the third “IAEA” to the ﬁfth “training.”
Figure 4 shows the results of the correspondence analysis of the feature word “responsibility.” The number of target words was 43.
The total number of words was 2,176 for the
6th, 982 for the 7th, and 1,285 for the 8th meeting. The correspondence analysis showed thatthe cumulative contribution of components 1
and 2 was 100% in a 3×43 cross-tabulation table. The 6th and 7th meetings were located to
the left side of the x-axis.
“Responsibility,” “management,” “record,”and “system” were distributed around the origin (0, 0). From there, there were characteristic
words such as “hospital” and “occupation” inthe 6th, “explanation” and “consider” in the 7th,and “regulation” and “pertaining to” in the 8th
meeting. There were clusters of “technologist,”“doctor,” “dental,” “justiﬁable,” and “qualiﬁca-

Fig.2 Bubble plot of meeting numbers and clusters

3.3 Correspondence analysis of the featureterms “record” and “responsibility”
Figure 3 shows the results of the correspon-

34 ◆ Journal of JART English edition 2023

Fig.3
training
particularimpactEU appear

2
laws

data

CT
academic society

mandate1component 2 (0.1751, 38.67%)

dence analysis for the feature word “record.”
The number of target words was 73. The total
number of words was 1,870 in the 3rd, 1,934 in
the 4th, and 1,944 in the 5th meeting. Correspondence analysis is based on a 3×73 crosstabulation table, with the proportion of occurrences (proﬁle) between each word or meeting
number determined by χ2 distance 15). The xaxis (component 1) represents the ﬁrst dimension result of the word or conference number,and the y-axis (component 2) represents thesecond dimension result of the word or conference number, simultaneously distributed in ascatter plot. The values (0.2777, 61.33%) on theaxes are contribution rates; the cumulative
contribution rate of components 1 and 2 was100%.
The origin (0, 0) represents the coordinatesof the average proﬁle; the closer to the origin,
the more evenly distributed the words in every
meeting. “Dose,” “exposure,” “medical,” “irradiation,” and etc., are some of these words. The
feature word (the one appearing only once)
appears on a straight line from the origin to themeeting number mark and outside of that
mark. The 4th and 5th meetings appear on theright side of the x-axis, and many words com-

IAEA
diﬃcult
0

examination

DRL

year

study individual

3
Japan

problem-1

dose

irradiation

possible management

doregulation

think

optimum
exposure
institutions
form
opinion consideration
medicalbestowed justiﬁable
suggestion

futureprotection
information

appropriate

one
just 5 partial
medicalnow
treatment receive clear
recordcomposestoragesee

all

4 importantburdenteacher

discussion-2

administrative

on-sitesubmitsafety-3hospital-2-1
0component 1 (0.2777, 61.33%)

1

Fig.3 Correspondence analysis: record

original articles
Content analysis in the proceedings “Study Group on the Appropriate Management of Medical Radiation”

Fig.4

now
viewpoint

hospitalcomponent 2 (0.1087, 41.02%)

2

think

extremely
occupation
exposurefacilities
1
each
6

justiﬁable
dodoctortraining
technologist
one
responsibility
dose
opinionmanagement
systempatient
examination
medical treatment
form

0
staﬀ

need

under

recordsafetyown

radiation

implementation

-1

case

explanation
medical-2qualiﬁcation
dentalconsiderpertaining to8regulation
writing
dutiesestablishment
guideline
policy7

at this timecorrespondence-20component 1 (0.1564, 58.98%)

2

Fig.4 Correspondence analysis: responsibilitytion” in the 6th and 8th meetings, and of “policy,” “guideline,” and “establishment” in the 7th
and 8th meetings. Some words were linearly
distributed between “hospital” in the 6th and “consider” in the 7th, but not between the 7th
and 8th, nor between the 6th and 8th.

4. Discussion
The revision of the ministerial ordinancemade it mandatory for the ﬁrst time to record
patient doses and required the establishmentof a dose control system. We were asked for
public comment two years prior to the announcement of the revision of the ministerial
ordinance (from January 9, 2019 to February 7,2019), and in March 2019, we received a noticefrom the Director General (Medical Policy Bulletin No. 0312 No. 7). Therefore, text mining of
the minutes of these proceedings was conducted to analyze the content.

mined 10 clusters according to the key wordsof the revised ministerial ordinance. This method is common in cluster analysis 16). If the distance (Height = 2.68) increases, the clusters areaggregated to 6 and each cluster contains more
words, while if the distance decreases, thenumber of words in each cluster is extremely
small. Although the analysis results may change
depending on clustering rules, consideration
was given to the keywords in the ministerial
ordinance revision.
Cluster 1 includes “dose,” “record,” and “exposure” and Cluster 2 includes “DRL;” Clusters
1 and 2 contain the key terms of the revision of
the ministerial ordinance. They appeared inthe 3rd, 4th, and 5th meetings, suggesting thatpatient dose control was conducted using DRL
and that discussions were held on recording.
Cluster 3 includes “protection” and “standard,”
Cluster 9 includes “doctor” and “ technologist,”
and Cluster 10 includes “responsibility” and“system,” suggesting that the discussions on the
person responsible for the safety management
system took place in the 6th–8th meetings.
Clusters 4–6 include words such as “page,”“documents,” “basic,” “consider,” “medical,” and“institutions,” mentioned when the secretaryexplained the meeting, as well as words for
medical facilities and equipment central to themeeting agenda, which generally appeared in
all meetings. Clusters 7 and 8 were the ﬁrst inwhich radiation-related laws such as the Law
Concerning Regulation of Radioactive Isotopes
were explained. Since this meeting included
non-experts in radiation, the ﬁrst half of themeeting served to explain trends in radiation
control and the second to discuss how to develop a control system.
4.2 Correspondence analysis of “record” and4.1 Relationship between cluster analysis andmeeting number

In cluster analysis, the words are clusteredaccording to their close positions of occurrence. This time, we have subjectively deter-“responsibility”

Although most text mining methods analyze
and evaluate the subject matter of a text using
the number of frequently occurring words as
an indicator, we believe that it is difﬁcult toArts and Sciences ◆ 35

capture the background of the subject matter.
The advantage of KHcoder3 is that the analyst
can extract and analyze words independently.
Through the cluster analysis described above,
the author chose “record” from Cluster 1 to focus on patient dose records and “responsibility” from Cluster 10 to focus on the exclusive
responsibility for the safety management system.
4.2.1 Feature word “record”

One of the major points of the revision of theministerial ordinance is the recording of patient doses. The target equipment are CT, IVR,
SPECT, and PET, which have high exposure
doses. To manage patient doses easily, management software use has become widespreadin clinical practice 17).
The 3rd meeting was the “IAEA.” According
to the minutes, international trends were introduced at the 3rd meeting. In the report, during
UNSCEARʼs global survey 18), Japan is struggling
to collect dose data. On the other hand, at the
IAEA, it was introduced that doses are managed by patient IDs through the smart card
project 19). The goal of the government is toestablish a system to record and track medical
exposure history (smart card project), as is being worked on by the IAEA, with the goal of
reducing medical exposure. The company expressed its ambition to make good use of its
my number card for this history tracking. There
was a “burden” in the 4th meeting. This was aconcern about the “on-site” “burden” of conducting “record.” They also asked for opinions
on how to make the “record” data easier to getout. Thus, better performance of medical
equipment and equipment capable of recording patient dose information in the radiology
information system, irradiation and electronic
medical records might decrease the burden on
the site of treatment allowing implementation.
Since 2000, the International ElectrotechnicalCommission has been displaying radiation doses on equipment, including computed tomog-

36 ◆ Journal of JART English edition 2023

raphy dose index and dose length product for
X-ray CT systems 20), and the reference air kerma rate, integrated reference air kerma, andintegrated area dose at the patient entrance reference point are displayed on IVR systems 21).
The information is centrally managed by dosemanagement software via the DICOM Radiation Dose Structured Report. However, clinicalsites are struggling due to the lack of test protocol names, etc. 22). Therefore, it is important
to standardize the medical information to facilitate dose control and to easily obtain representative Japanese values in each examinationsite. The 5th meeting included “training.” It wasstated by the secretary that this can be properly managed to justify and optimize radiation
protection by “training” and “record” of doses
to radiation practitioners.
Based on the above, from the 3rd to the 5th
meetings, proper management of radiologicalpractice was agreed to be carried out throughdose recording and training.
4.2.2 Feature word “responsibility”

There was “occupation” in the 6th meeting.
The responsible person can be a doctor, dentist, or radiology technologist who can irradiate
the human body (i.e., can press a button on aradiation device) but who is not responsible
for the need of radiological treatment, but canbe a radiology technician because he/she establishes guidelines and systems. An “explanation” was provided at the 7th meeting. Despite
the opinion that nurses could provide explanations to patients to lower the burden on physicians, it was determined that medical treatment
and explanation belong together, as requiredby the World Health Organization, the IAEA 23),and others 24, 25). The 8th meeting, held in response to public comments, referred to “regulations.” It was noted that there were many
comments regarding the regulations for safety
managers. The secretary proposed that a radiological technologist can be a safety manager
only when the system is justiﬁed by a doctor ororiginal articles
Content analysis in the proceedings “Study Group on the Appropriate Management of Medical Radiation”

dentist and can give instructions to the radiological technologist. The role of the responsible person is the justiﬁcation of radiologicalinspections but the establishment of a safety
management system, including the formulationof guidelines and the implementation of training.
Accordingly, the 6th–8th meetings served to
discuss the selection of the responsible person
and the establishment of a management system.

Conclusion
In the “Study Group on the Proper Management of Medical Radiation” the 1st meeting ex-

References
1） Japanese Society of Nuclear Medicine: Enforcementof the Ministerial Ordinance Partially Revising the Ordinance for Enforcement of the Medical Care Act, etc.,
http://jsnm.sakura.ne.jp/wp_jsnm/wp-content/uploads/
2019/03/0b991eb1e78fb147b7db007c53e1d308.pdf(March 31, 2021).
2） ICRP: Recommendations of the International Commission on Radiological Protection, ICRP Publication
26, Ann. ICRP, 1 (1977).
3） Yasuhito SASAKI: Considerations as a former member of the International Commission on RadiologicalProtection (ICRP), Trends in the sciences, 25.3: 1218, 2020.
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https://www.mhlw.go.jp/stf/shingi/other-isei_436723.
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plained the relevant laws and regulations, the3rd, 4th, and 5th meetings discussed the necessity of dose records and the subjects of training
in the safety management system, and the 6th,
7th, and 8th meetings discussed the guidelines
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regulations on the responsible person, records,
training, etc.
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trends to properly manage justiﬁcation and optimization in radiological practice.

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Research, 42-43, Nakanishiya Publishing Co., 2020.
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Cloud-based Dose Management System “MINCADI”
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38 ◆ Journal of JART English edition 2023

Next Decade, https://www.iaea.org/sites/default/
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Arts and Sciences
original articles

Received December 24, 2021; accepted May 16, 2022

Student issues based on the results of clinicaltraining of radiological technologists
MUTO Hiroe，NAKAYA Koji，MATSUURA Kanae
Department 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. 69 no. 842: 16-23, 2022.
Key words: Clinical training education, radiological technologist, student assignments, COVID-19【Abstract】

The purpose of this study was to analyze the results from a 3-year clinical training evaluation conducted at theauthorsʼ university and to identify problematic issues in training education for students who aim to become radiological
technologists. Participants were 325 university students who were in their fourth year of clinical radiological
technologist training between 2019 and 2021. The clinical training evaluations of these students comprise a series of
items and sub-items. We asked clinical training instructors to grade each item. Students had little knowledge about thecost of radiological examinations, and some students were unable to write training reports sufﬁciently. An analysis ofclinical training evaluations indicated that some radiological technologist students had little knowledge about the costof radiological examinations and showed poor report writing ability. Future clinical training should seek to strengthen
the guidance offered to students on these topics in pre-education before conducting clinical training. We believe our
ﬁndings can help facilitate further improvements in the development of clinical training.

Introduction
University training for radiological
technologists in Japan follows a four-year
curriculum. In those four years, students
acquire the specialized knowledge necessary
for practicing as a radiological technologist.
In addition to classroom lectures, university
education involves clinical skills training toprepare radiological technologists to workat a hospital. X-ray photography education,
moreover, is continuously advancing, and thus
clinical training education is indispensablefor the production of aspiring radiological
technologists 1) . At our university, clinicaltraining is provided in the first half of the
fourth year; during this training phase, students
are taught by radiological technologists
working in hospitals. The clinical training is
conducted in a general hospital, and our aim
is for students to acquire the clinical skills forthe modality in which a given radiological
technologist practitioner is engaged: generalradiography, computed radiography,
magnetic resonance imaging, angiography,
ultrasonography, nuclear medicine, andradiotherapy. The Department of Radiation
Technology Science at our university attracts
more than 100 students from all over Japanevery year. Therefore, because it is impossible
to provide clinical training in a hospital near
the university for all the students, we ask
students to conduct their clinical practice attheir local hospital. In the past, clinical training
centered on the tour type has been conducted.
However, in recent years, participatory clinicaltraining has begun to be adopted to help
students acquire more clinical skills 2). At thispoint in their training, students do not yet havea radiological technologist license; therefore,
they are not allowed to irradiate patients,
although they have acquired other clinicalskills through clinical training (e.g., patient
treatment, image analysis processing, andunderstanding of examination content).
As part of our clinical training grade
Arts and Sciences ◆ 39

evaluations, hospital-based clinical training
instructors engaged in student guidance areasked to rate the grade evaluations createdby our university. On the basis of the grade
evaluations provided by the clinical instructors,
the credits for clinical training are approved or
rejected. However, we realized the potential
usefulness for clinical training development(an d t h u s for students) of identify ing
potentially problematic issues from among thegrade evaluation data. Therefore, the purposeof this study was to analyze the past 3 yearsʼ
grade evaluations for clinical training at our
institution in Japan and to identify problems inclinical training education for students.

Materials and Methods
Targets

A total of 325 participants comprised: 100
students (69 male, 31 female) who underwent
their fourth-year university clinical training
in 2019; 108 students (61 male, 47 female)
who underwent their fourth-year university
clinical training in 2020; and 117 students(69 male, 48 female) who underwent theirfourth-year university clinical training in 2021.
The prescribed duration for clinical training
set by our university is 57 days (training
time per day is 8 hours). However, in 2020
and 2021, the clinical training period forsome students was shortened owing to the
response of the local hospital in which they
were training to the effects of coronavirus
disease 2019 (COVID-19) infection. This study
was approved by our University ʼ s Conflictof Interest Management Committee and its
Clinical Research Ethics Review Committee.
Grade evaluations for clinical training
Table 1 shows the items that comprise theclinical training evaluation for our university.
The main items used for evaluation are as
follows: item 1 evaluates the acquisitionof basic practical radiological technologist

40 ◆ Journal of JART English edition 2023

skills; item 2 evaluates the development ofknowledge about and analytical ability for
operating the hospital radiation department;
item 3 evaluates the ability to respond
appropriately to patients; and item 4 evaluates
the development of responsibility andawareness as a member of the medical team.
To assess the topics covered in the main
items in more detail, seven sub-items wereset for each main item, as shown in Table
1 . After clinical training is completed, theclinical training instructor evaluates all the
sub-items for each student on a 4-point scale(1 point: inferior, 2 points: standard, 3 points:
good, 4 points: excellence). From FY2019 toFY2021 the clinical training evaluations wereconducted using the same method describedabove. The setting and evaluation method forthese clinical training evaluation items werecreated by the university ʼ s clinical training
instructor and have been used for 3 years
to evaluate the universityʼs clinical training
program.
Comparison of clinical training evaluation
scores (comparison of sub-items)

The sub-item scores (average value ±standard deviation (SD)) for the clinicaltraining evaluation for all students (total
students from 2019 to 2021) were calculated.
The score for each sub-item (average value± SD) was calculated for each year, and acomparison was made to see if there weredifferences in each sub-item score in eachyear.
Comparison of clinical training evaluation
scores (comparison of main items)

The average values ± SDs of the main items
were calculated from the average sub-itemvalues for all students, and the overall scoresfor each main item were compared. The
average values ± SDs of the main items foreach year were calculated from the averagevalue of the sub-items for each year, andoriginal articles
Student issues based on the results of clinical training of radiological technologists

Table 1 Main and sub-items for clinical training evaluation
Items for grade evaluation in clinical training

Main item 1: Acquire basic practical skills as a radiological technologist
Sub-item 1-1. You can work on pre-learning and take part in practical training.
Sub-item 1-2. You can record what you experienced in training in the report and use it in future training.
Sub-item 1-3. You can clarify your own tasks from daily reports and study to gain knowledge that you lack.
Sub-item 1-4. You can work on the tasks you have been instructed to do and give feedback on the next dayʼs training.
Sub-item 1-5. You know the structure and installation of the hospital that considers patient safety (including infection
prevention and accident prevention) and comfort, and you can explain these in the report.
Sub-item 1-6. You understand the structure and installation of hospitals with staff safety (including infection prevention
and accident prevention) and comfort in mind, and you can write down their characteristics in a report.
Sub-item 1-7. You can correlate and analyze the knowledge and theory learned in the classroom with the experience andsituations in clinical practice.
Main item 2: Develop knowledge about and analytical skills for the operation of the hospital radiation department
Sub-item 2-1. You comply with the rules set by the training facility.
Sub-item 2-2. You do not view electronic medical records without the permission of the leader.
Sub-item 2-3. You do not record any personally identiﬁable information in the report.
Sub-item 2-4. During training, you do not leave your records or belongings on the desk in the imaging room or elsewhere.
Sub-item 2-5. You understand the functions and roles of the Radiology Department members (chief radiological
technologist, sub-chief radiological technologist, chief radiological technologist of each modality, etc.).
Sub-item 2-6. You understand the role of the chief for each modality.
Sub-item 2-7. You understand the medical fees that are required for each radiological examination.
Main item 3: Learn how to respond appropriately to patients
Sub-item 3-1. Your appearance is suitable for medical personnel, and you can perform clinical training.
Sub-item 3-2. You can greet patients, staff, and leaders, etc.
Sub-item 3-3. You use polite language, such as using honoriﬁcs, when talking to patients.
Sub-item 3-4. You give an honoriﬁc title to your surname when you call a patient.
Sub-item 3-5. You try to read the patient's emotions in their facial expressions and wording.
Sub-item 3-6. You can respond to the patient with a clear and easy-to-hear voice.
Sub-item 3-7. You can ﬂexibly adapt to children and elderly patients.
Main item 4: Develop responsibility and awareness as a member of the medical teamSub-item 4-1. You are not late for clinical training.
Sub-item 4-2. You can keep the time you have promised to your teacher or clinical practice leader.
Sub-item 4-3. You reveal your whereabouts to the clinical practice leader and act (i.e., do not take a break without
permission).
Sub-item 4-4. You can meet deadlines for submitting clinical training reports and other assignments.
Sub-item 4-5. You strive to improve what has been noted by clinical practice leaders and teachers.
Sub-item 4-6. You take care of your own health.
Sub-item 4-7. If you have any questions, you ask or consult with the medical team leader.

the overall scores for the main items werecompared to identify differences.
Statistical analysis

T h e K r u s k a l - Wa l l i s t e s t o f o n e - w a y
ANOVA was used to test for significance.
The significance level was set to p < 0.05.
The P-value used a two-sided test. When asignificant difference was observed between
groups, the p-value-corrected Dann-Bonferroni
test was used to determine which groupdiffered significantly. Again, the significancelevel was p < 0.05. We used Statistical Package
for the Social Sciences (SPSS), version 26.0
(SPSS Inc., Chicago, IL, USA) for theseanalyses.

Results
Comparison of clinical training evaluation
scores (comparison of sub-items)
Figure 1 shows the results of the clinicaltraining evaluation scores for each sub-item forall students (total students from 2019 to 2021).
The scores for each sub-item were as follows:
1-1 was 3.13 ± 0.62, 1-2 was 3.23 ± 0.60, 1-3
was 3.15 ± 0.60, 1-4 was 3.23 ± 0.59, 1-5 was
3.07 ± 0.53, 1-6 was 3.05 ± 0.53, 1-7 was 3.04
± 0.57, 2-1 was 3.55 ± 0.54, 2-2 was 3.68 ±0.50, 2-3 was 3.67 ± 0.47, 2-4 was 3.44 ± 0.55,
Arts and Sciences ◆ 41

Fig. 1

Evaluation score for clinical training

5
4
3
2
1
0

1-1 1-2 1-3 1-4 1-5 1-6 1-7 2-1 2-2 2-3 2-4 2-5 2-6 2-7 3-1 3-2 3-3 3-4 3-5 3-6 3-7 4-1 4-2 4-3 4-4 4-5 4-6 4-7Sub-item number
FIGURE 1. Scores for sub-items in the clinical training evaluations for all students (total students from 2019 to

Figure1 TheScoresfortheclinical2021).
horizontal blackline sub-items
indicates the averagein
scoreof 3 points(good). training evaluations
for all students (total students from 2019 to 2021). The
Fig. 2horizontal black line indicates the average score of 3 points(good).

Evaluation score for clinical training

5
** **

*

*

4

*

*

**
**

Comparison of clinical training
evaluation scores (comparison

3
2019

2

were p < 0.01). The results of
the Dann-Bonferroni test wereas follows: p < 0.05 was seen
between 2020 and 2021 in 3-2,
between 2020 and 2021 in 3-5,
between 2019 and 2020 in 4-2,
between 2020 and 2021 in 4-5,
between 2019 and 2020 in 4-6,
and between 2020 and 2021
in 4-6. We observed p < 0.01
between 2019 and 2020 in 2-4,
between 2020 and 2021 in 2-4,
and between 2020 and 2021 in
4-7.

2020
2021

of main items)
Figure 3 shows the scores foreach of the main items for all
students; they were: 3.13 ± 0.08
01-1 1-2 1-3 1-4 1-5 1-6 1-7 2-1 2-2 2-3 2-4 2-5 2-6 2-7 3-1 3-2 3-3 3-4 3-5 3-6 3-7 4-1 4-2 4-3 4-4 4-5 4-6 4-7
for 1, 3.35 ± 0.32 for 2, 3.36
Sub-item number
FIGURE 2. Scores for sub-items in the clinical training evaluations for each year. The Kruskal-Wallis test was used to test for± 0.25 for 3, and 3.57 ± 0.18
Figure2 Scoressub-items
clinicaltraining
evaluations
significant differences
between otherfor
groups.
The significance levelin
wastheset to P <0.05.
When a significant
difference
was found, theP-value-corrected Dann-Bonferroni test was used to determine which group differed significantly.
for 4. The Kruskal-Wallis testfor each year. The Kruskal-Wallis test was used to test
*P <0.05, **P <0.01.
for significant differences between other groups. The
showed a signiﬁcant difference
significance level was set to P < 0.05. When a significant
between groups ( p < 0.05). The
difference was found, the P-value-corrected DannBonferroni test was used to determine which group differed
Dann-Bonferroni test showed asignificantly.
significant difference between*P < 0.05, **P < 0.01.
main items 1 and 4 ( p < 0.01).
Figure 4 shows a graph
2-5 was 3.23 ± 0.54, 2-6 was 3.12 ± 0.54, 2-7
comparing each main item in the clinicalwas 2.80 ± 0.52, 3-1 was 3.69 ± 0.48, 3-2 wastraining evaluation classified in 2019–2021.
3.57 ± 0.54, 3-3 was 3.47 ± 0.55, 3-4 was 3.44
Scores for main item 1 were: 3.11 ± 0.08 in± 0.54, 3-5 was 3.12 ± 0.60, 3-6 was 3.19 ±2019, 3.17 ± 0.07 in 2020, and 3.11 ± 0.11 in
0.64, 3-7 was 3.04 ± 0.59, 4-1 was 3.79 ± 0.41,
2021. Scores for main item 2 were: 3.30 ± 0.32
4-2 was 3.72 ± 0.46, 4-3 was 3.68 ± 0.50, 4-4
in 2019, 3.41 ± 0.33 in 2020, and 3.36 ± 0.32 in
was 3.57 ± 0.55, 4-5 was 3.39 ± 0.58, 4-6 was
2021. Scores for main item 3 were: 3.35 ± 0.22
3.56 ± 0.55, and 4-7 was 3.29 ± 0.61.
in 2019, 3.44 ± 0.25 in 2020, and 3.29 ± 0.26 in
2021. Finally, scores for main item 4 were: 3.54
Figure 2 shows a graph comparing each
± 0.26 in 2019, 3.65 ± 0.17 in 2020, and 3.52 ±sub-item of the clinical training evaluation
0.21 in 2021. The Kruskal-Wallis test showedclassiﬁed in 2019–2021. The Kruskal-Wallis test
no signiﬁcant difference between the years inrevealed significant differences between the
any of the major items (n.s.).
years for the sub-items 2-4, 3-2, 3-5, 4-2, 4-5,
4-6, and 4-7 (sub-items 3-2, 3-5, 4-2, and 4-5
were p < 0.05, and sub-items 2-4, 4-6, and 4-7
1

42 ◆ Journal of JART English edition 2023

original articles

Fig. 3Student issues based on the results of clinical training of radiological technologists

Evaluation score for clinical training

5

Discussion**

4

Clinical training evaluation of
main item 2

5
4
3
2
1
0

2019

2020
By year2021

5

Clinical training evaluation of
main item 4

Clinical training evaluation of
main item 3

Clinical training evaluation of
main item 1

The purpose of this study was to analyze
the grade evaluations for clinical training for3
the past three years at our institution and to2
identify problems in clinical training education
for students. For students who aim to become1
medical professionals, clinical training
0
1
2
3
4
education can give them the necessary skills
Main item number
for clinical practice. Therefore, this research
Figure3 items
Scoresfortraining
main
itemsforin
the clinicalto identify and highlight problematic
FIGURE 3. Scoresfor mainin the clinicalevaluations
all students(total students from 2019attempts
to2021). The Kruskal-Wallis test training
was used to testevaluations
for significant differences
other groups. The significancefor between
all students
in studentsʼ clinical training to inform
level was set to P <0.05. When a significant difference was found, the P-value-corrected Dann-Bonferroni testissues
wasstudents from 2019 to 2021). The
used to determine which group (total
differed significantly.
and facilitate the further development and**P <0.01.
Kruskal-Wallis test was used to test forsignificant differences between otherimprovement of clinical training education.
groups. The significance level was set
First, the method used for clinical training
to P < 0.05. When a significant difference
evaluation
will be mentioned. The Likert scale
was found, the P-value-corrected DannBonferroni test was used to determine
is used for the clinical training evaluation
which group differed significantly.
of this study. In order to easily evaluate the**P < 0.01.
comparison of clinical training evaluation
items and the comparison of each year, theanalysis was performed by quantifying the
Likert scale. In addition, we asked clinical

4
3
2
1
0

2019

2020
By year

2021

a

b

c

d

5
4
3
2
1
0

2019

2020
By year

2021

2019

2020
By year

2021

5
4
3
2
1
0

Figure 4 Scores for main items in the clinical training evaluations for each year. (a) Main item 1 score. (b) Main
item 2 score. (c) Main item 3 score. (d) Main item 4 score. The Kruskal-Wallis test was used for thesignificance test between other groups. The significance level was set to P < 0.05. No significant
difference was found in any of the Main items (n.s.).
Arts and Sciences ◆ 43

training instructors to evaluate the Likert scalein four stages without using the median. This isbecause the absence of an intermediate value
makes it possible to remarkably evaluate thequality of each item of students and facilitate
future student guidance.
The ﬁrst notable outcome from this study isthe consistently satisfactory average scores forthe clinical training results among all students
across all 3 years. The average score for mostof the sub-items was 3.0 or higher, whichindicates that students were able to perform
clinical training well in the areas and topics
covered by the evaluation items. Only subitem 2-7 had an average score of less than
3. This item addresses medical fees. Clinicaltraining instructors mainly provide informationand direction about how to handle medical
devices and how to communicate with patientsduring clinical work. While some clinicaltraining instructors also inform students about
medical fees, most do not. Additionally, evenin university classes, there are no official
lectures that explain medical fees for eachtype of medical examination. This can help
explain why these studentsʼ understanding of
this item was the poorest, and the associatedscores the lowest. However, when a student
becomes a radiological technologist and works
at a hospital, knowledge about medical feesis always essential. Patients often ask medical
staff about the cost of their tests. Therefore, itis necessary to introduce classes to improvestudentsʼ knowledge about medical fees.
The second outcome to underscore is thehigher grades observed for some of the subitems in 2020 compared with other years.
Furthermore, no differences were observed in
the average scores for the sub-items in 2019and 2021. In 2020 and 2021, studentsʼ clinicaltraining underwent changes inﬂuenced by the
COVID-19 pandemic. Recent clinical training
education has shifted to address COVID-19
infections 3). More specifically, the clinicaltraining curriculum was unexpectedly changed

44 ◆ Journal of JART English edition 2023

in some cases, and/or the clinical training
period shortened, to prevent students fromcontracting COVID-19, and to protect studentsʼ
mental health4，5). Moreover, students whose
clinical training period was shortened werealso expected to study independently when
they were not engaged in clinical training.
Thus, although many facilities were forced tochange some aspects of their clinical training
teaching methods, some of the evaluation
items were scored the same or better than
before the changes were enacted. Currently,
to improve clinical training, workshops arealso held to further educate clinical training
instructors. Some reports indicate that clinicaltraining instructors have low participation
rates in these workshops6), despite bearing
all the responsibility for their students during
the clinical training period1). In addition, thequality of the instructorʼs teaching ability has
a substantial impact on student learning6-9).
Therefore, in Japan, to improve the leadershipskills of clinical training instructors who train
radiological technologists, the number offacilities participating in these workshop isincreasing. Furthermore, university faculty
members continue to work well with students
and hospital-based clinical training instructors
to improve clinical training. Therefore, evenduring the period of restricted clinical training
owing to COVID-19, the students were able toreceive high-quality clinical training education.
The reasons why we were able to carry out
sufﬁcient clinical training even with COVID-19
disasters are sufﬁcient guidance on infection
control in pre-education of clinical training",
thoroughness not to go out unnecessarily",students will be on standby at home from
2 weeks before the start of clinical training",
and Students and clinical training instructors
and faculty members will be in close contact",
etc. In addition, the students themselves kept
a high awareness of infection prevention, andthey wanted to acquire clinical techniques,
so we think that they were successful in theoriginal articles
Student issues based on the results of clinical training of radiological technologists

clinical training during the prevalence of
COVID-19.
Here, we will describe the attendanceof student education guidance in order toimprove the leadership of clinical training
instructors. On September 30, 2021, theMinistry of Health, Labor and Welfare ofJapan revised the guidelines for guidanceat radiological technologist training centers.
As part of the amendment, it is stated that
hospitals that conduct clinical training shouldhave radiological technologists who havecompleted the radiological training instructor
training course10). Improving the leadership ofclinical training instructors is a very important
item, and we hope that this revision will leadto the further development of clinical training
education.
A comparison of the main items for all grades
showed that the acquisition of basic practicalabilities as a radiological technologist was
the lowest scoring item. This main item was,moreover, considerably lower than the itemthat addresses fostering responsibility andawareness as a member of the medical team;its content deals mainly with sub-items that
evaluate the technological knowledge required
to complete a report. The clinical training
instructor requires students to write their own
thoughts in their own words in their reports,
including their experiences and activities on
a given day of clinical training. However,some students find it difficult to express intheir own words what they were involved induring medical examinations on the day. Suchstudents rather describe the contents of the
textbook as if it were their report. Therefore,
we would like to offer proper guidance on
how to write a report through pre-education inclinical training.
In our comparison of main items in theclinical training evaluations for each student
cohort, we used the same evaluations foreach year. While some sub-items differedconsiderably across cohorts, a comprehensive

assessment of the main items indicated there
were no differences in evaluations acrosscohorts.
On the basis of the foregoing analyses, wenoted that students lacked knowledge about
medical fees and that some students could
not write reports well. To improve these
aspects in future, we would like to enhance
the relevant instructions in pre-education
courses and in-person clinical training. Clinicaltraining education is necessary for preparing
students to play active roles as radiological
technologists. We want students to be at
the forefront of the medical field when they
become radiological technologists and engage
in clinical work. Thus, the problems identiﬁedin this research can facilitate improvementsin those areas to produce higher quality
radiological technologists.
One limitation of this study is that theclinical training evaluation we analyzed was
only a four-stage evaluation (i.e., 1 point:
inferior, 2 points: standard, 3 points: good,
4 points: excellent). If the evaluation stages
were extended, differences may appear inother items. Therefore, in the future, wewould like to review the scoring criteria forevaluations. A further limitation is the absenceof evaluation for each modality in the clinicaltraining evaluation we studied; rather, it isan evaluation of the entire clinical training
process. Importantly, students have likes anddislikes and various weaknesses in different
modalities. Therefore, a separate assessment
should be conducted for each modality ʼ sclinical training evaluation. Additionally,
reports indicate that remote lectures havebeen adopted in various school settings in
response to the spread of COVID-19, and thatthey have had a positive educational effectfor students 11-14). Furthermore, education thatincorporates e-learning into existing lessons
has been shown to be effective 5，15，16). The
e-learning system is not introduced in thisresearch. we would like to create an e-learning
Arts and Sciences ◆ 45

program for distance learners whose clinicaltraining has been interrupted or shortened
because of COVID-19. Finally, another study
reported on the creation and effective use of avideo recording of a radiological technologistʼs
work for student education 17). We wish tocontribute to the further development ofclinical training education by incorporating thetrials of those previous reports.

Conclusion
The ﬁndings from our analysis of the grade
evaluations for clinical training for the past
three years at our institution show that somestudentsʼ knowledge about medical fees was
weak and their reports poorly written. It
is, therefore, essential to improve studentsʼ
knowledge and skills in the areas in which
they are weakest by including a pre-education
phase for clinical training and by enhancing
the future development of clinical training
education.

Acknowledgments
We would like to express our deep gratitude
to all the radiological technologists at thehospital who were involved in the clinicaltraining of our students. We thank Anita
Harman, PhD, from Edanz (https://jp.edanz.
com/ac) for editing a draft of this manuscript.
Conflicts of Interest / Funding Statement

The authors declare no conﬂicts of interest
associated with this manuscript.
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Arts and Sciencesmaterial

Received January 18, 2021; accepted May 26, 2021

The effects of electrical muscle stimulation on
facial muscles: Volume change of facial muscles
measured with magnetic resonance imaging
NAKAYA Koji1），MUTO Hiroe1），MATSUURA Kanae1），SUDO Shu2），YAMANAKA Aya2）
1）Department of Radiological Technology, Faculty of Health Science, Suzuka University of Medical Science2）Research Dept. Mikimoto Pharmaceutical CO., LTD.

Note: This paper is secondary publication, the ﬁrst paper was published in the JART, vol. 69 no. 831: 40-47, 2022.
Key words: electrical muscle stimulation, buccinator muscle, masseter muscle, slimming effect on the face
【Abstract】

Purpose : Electrical muscle stimulation (EMS) delivers a low-intensity stimulus to the nerves in the muscle to causemuscle contraction, and can result in a cosmetic effect. In this study, we measured volume changes of facial muscles
before and after using EMS facial equipment via magnetic resonance imaging, and investigated the effects of EMS
facial equipment on facial muscles.
Methods: Eight sessions of facial treatment were performed on healthy volunteers using EMS facial equipment.
T2-weighted images were acquired before and after using the EMS facial equipment, and volume changes in the
buccinator and masseter muscles before and after using EMS facial equipment were measured from the images.
Results : The use of EMS facial equipment caused a decrease in masseter muscle volume in magnetic resonanceimages.
Conclusion : The results suggested that the use of EMS facial equipment had a clear effect on facial muscles, and thata facial treatment effect could be obtained even with short-term use.

1．Introduction
Human skin shows the effects of aging overtime 1). Many women use cosmetics and medicines to prevent skin aging and rejuvenate theskin 1, 2). In recent years, the market for beauty
appliances has grown rapidly and demand isincreasing 3). In addition, many beauty salonsoffer treatments that attempt to prevent skinaging using beauty equipment. In recent years,
beauty appliances and esthetic salons havedeveloped and utilized facial equipment using electrical muscle stimulation (EMS). EMS
involves the application of a low-intensity
electrical stimulus to the nerves in the muscle,causing contraction of the muscle 4 - 6) resulting
in a cosmetic effect. EMS is also used as an exercise device for muscle training in the sports
industry 6). Furthermore, it has been reported
that EMS is effective for dieting 7). Facial EMS is
now widely used for skin anti-aging and diet-ing purposes, providing a facial treatment that
stimulates facial muscles and promotes facialmuscle movement 8). It contracts the musclesof the face and gives a slimming effect on theface.
In the current study, we examined the effects of EMS on facial muscles. Many people
regularly perform EMS on their face, reporting
beneﬁcial effects on their appearance 9). However, the extent to which EMS affects facialmuscles is currently unclear. There are no reports quantifying the effects of EMS as a facial
treatment. Therefore, we sought to clarify theeffect of EMS by using the volume change offacial muscles. Imaging of facial muscles canbe taken by computed tomography (CT) andmagnetic resonance imaging (MRI), etc. MRI
has better contrast resolution than CT 10). Muscles with a small area can be evaluated moreaccurately from MR images. Therefore, wethought that the facial treatment effect of EMS
Arts and Sciences ◆ 47

could be evaluated if the muscles were activated by EMS and the degree of muscle contraction could be captured by MR images. In
addition, there is T2 -weighted imaging (T2WI)
in the MR sequence. It has been reported that
this sequence is anatomically easy to see andprovides good contrast 11). Therefore, we would
like to adopt T2WI for the MR sequence thatimages facial muscles. In the current study,
we measured changes in the volume of facial muscles before and after using EMS facial
equipment via T2WI of MRI, and investigatedthe effects of EMS facial equipment on facialmuscles.

2．Materials and Methods
2-1. Subjects

The subjects were 10 healthy women, aged

21 to 22 years (mean 21.7 ± 0.5 years), who
volunteered to take part. This study was carried out with the approval of the Ethics Committee of Suzuka University of Medical Sciences.
2-2. Use of EMS facial equipment

PEARL FACE ESTHE Sonic EX (ITO CO.,LTD., Saitama, Japan) was used as the EMS
facial equipment. The method of using the
EMS facial equipment is shown in Fig.1. Whenusing the EMS facial equipment, pearly sonicgel (Mikimoto Pharmaceutical CO., LTD., Mie,
Japan) was applied to the tip of the probe. The
electromagnetic waves of EMS used medium
frequencies that affect muscles. Electromagnetic wave output was performed at 13 out of
40 stages. EMS facial equipment was used for
20 minutes per person, and was used twice a

Fig.1 How to use electrical muscle stimulation facial equipment.
Instructions provided by Mikimoto Pharmaceutical CO., LTD.

48 ◆ Journal of JART English edition 2023

material
The effects of electrical muscle stimulation on facial muscles: Volume change of facial muscles measured with magnetic resonance imaging

week. In total, subjects underwent eight treatment sessions from September 2020 to October 2020. Subjects practiced using the EMS
facial equipment, and, after securing an environment in which to do so, operated the EMS
facial equipment themselves.
2-3. Acquisition of magnetic resonance imaging

MRI was performed before the use of the
EMS facial equipment and within 2 to 3 days
after the last day of use. An ECHELON 1.5T
scanner (Hitachi, Ltd., Ibaraki, Japan) was usedas the MRI device. A head coil was used as
the receiving coil. T2WI was used as the imaging sequence, and the imaging conditions for
the T2WI are shown in Table 1. The imaging
cross-section was set so that a cross-section
perpendicular to the long axis of the cheekcould be obtained.

Table 1 Imaging conditions for T2 -weighted images
Parameters
TR (ms)

3,000

TE (ms)84

FOV (mm)200

Matrix

320 × 320

FA90

IR Pulse

off

Thickness (mm)3Interval

3

Multi slice

40

E. Factor

12

NSA

2

Bandwidth (Hz/pixel)

147.5

2-4. Comparison of facial muscle volume
before and after using EMS facial equipment

The muscles used for volume measurement
were the buccinator muscle, which is involvedin facial expression, and the masseter muscle,
which is involved in jaw movement and mastication. The masseter muscle is used to open
and close the mouth and is also an importantmuscle for facial expression 12, 13). Also, thesemuscles are the parts where the EMS probe is
in close contact, and it was the subject of evaluation. For measuring the volume of both muscles, the region of interest (ROI) tool attachedto the workstation of the MR device was used.
MR images were acquired by 2-demensional
scan (3 mm slices at 3 mm intervals). The ROI
was surrounded by both muscles in all slice
cross-sections where both muscles were depicted (Fig.2). Add up the muscle areas of all
cross sections, and the volumes of both left
and right muscles were measured. Volumesof the buccinator and masseter muscles werecompared before and after the use of the EMS

Fig.2 Buccinator and masseter muscles region ofinterest settings

facial equipment. The ROI was set by a radiological technologist with 10 years of experience in MRI work.
2-5. Statistical analysis

Wilcoxon signed-rank test was used for statistical analysis of volume changes in the buccinator and masseter muscles before and after
use of the EMS facial equipment. Statisticalsigniﬁcance was deﬁned as a P-value < 0.05.
Arts and Sciences ◆ 49

We analyzed using Statistical Package for theSocial Sciences (SPSS), version 26.0 (SPSS Inc.,
Chicago, IL, USA) for statistical analysis.

3．Results
3-1. Volume change of buccinator muscle
Fig.3 shows the volume of the right bucci-

nator muscle before and after using the EMS
facial equipment. The volume of the rightbuccinator muscle before and after using the
EMS facial equipment was 1.15 ± 0.43 cm3 and1.03 ± 0.27 cm3, respectively. There was no
signiﬁcant difference in the volume of the rightbuccinator muscle before and after using the
EMS facial device (P = 0.508). Fig.4 shows thevolume of the left buccinator muscle before
and after using the EMS facial equipment. The
left buccinator muscle volumes before and after using the EMS facial equipment were 1.04
± 0.45 cm3 and 0.88 ± 0.36 cm3, respectively.
There was no significant difference in thevolume of the left buccinator muscle before
and after using the EMS facial equipment (P =Fig.3 Volume of the right buccinator muscle before and after using electricalmuscle stimulation facial equipment

Fig.4 Volume of the left buccinator muscle before and after using electricalmuscle stimulation facial equipment

50 ◆ Journal of JART English edition 2023

material
The effects of electrical muscle stimulation on facial muscles: Volume change of facial muscles measured with magnetic resonance imaging

0.059).
3-2. Volume change of masseter muscle
Fig.5 shows the volume of the right massetermuscle before and after using the EMS facial
equipment. The volume of the right massetermuscle before and after using the EMS facial
equipment was 19.70 ± 5.86 cm3 and 18.13 ±4.73 cm3, respectively. There was a signiﬁcantdecrease in the volume of the right massetermuscle after the use of the EMS facial devicecompared with before (P < 0.05). Fig.6 shows

the volume of the left masseter muscle before
and after using the EMS facial equipment. The
left masseter muscle volume before and afterusing the EMS facial equipment was 20.44 ±6.26 cm3 and 19.06 ± 6.04 cm3, respectively.
There was a signiﬁcant decrease in the volumeof the left masseter muscle after the use of the
EMS facial device compared with before (P <0.05).

Fig.5 Volume of the right masseter muscle before and after using electricalmuscle stimulation facial equipment

Fig.6 Volume of the left masseter muscle before and after using electricalmuscle stimulation facial equipment
Arts and Sciences ◆ 51

4．Discussion
We measured the volume change of facialmuscles from T2WI of MRI before and afterusing the EMS facial equipment, and examinedthe effects of the EMS facial equipment on the
facial muscles.
In the current study, the buccinator and masseter muscles were targeted to induce changes
in the volume of facial muscles. The buccinatorand masseter muscles were selected because
they provided suitable contact with EMS facial
equipment, and it was relatively easy to set an
effective ROI than other muscles in the MRI
images. Regarding the buccinator muscle, there
were no changes in the volume of the left andright buccinator muscles following the use of
EMS facial equipment. This ﬁnding may haveoccurred for several reasons. First, the volumeof the buccinator muscle is small, and no signiﬁcant volume change was observed. Furthermore, the EMS facial equipment was used by
the subjects themselves. Using the EMS facial
equipment took exactly 20 minutes. However, because the procedure was performed by
the subjects themselves, there were individual
differences in the effects, and some subjects
did not exhibit an effect on the buccinatormuscle, which has a small volume. In addition,
there may have been limited reproducibility,
because the ROI for measuring volume wasset manually. However, the average volume
decreased after using the EMS facial equipment. Thus, the results suggest that a signiﬁcant decrease in volume may be obtained bycontinuing to use the EMS facial equipment.
In contrast, there was a marked effect of the
EMS facial equipment on the masseter muscle,with the volume of the left and right massetermuscles signiﬁcantly decreasing after using the
EMS facial equipment. The masseter muscle
has a larger volume than the buccinator muscle and came into contact with the EMS facial
equipment more often. Therefore, the masseter muscle volume was signiﬁcantly reduced,

52 ◆ Journal of JART English edition 2023

even though the equipment was controlled by
the subjects themselves. However, there werecases in which the volume of the massetermuscles after EMS did not decrease. As withthe buccinator muscle, the cause of the cases
where the volume reduction was not obtained
after EMS was that the subjects themselves
used EMS. Therefore, it is considered that there
were cases in which the probe could not stimulate the muscles well and the facial treatment
effect could not be obtained. In the future,
we would like to implement it after sufﬁcienttraining on how to use the probe. Thus, only
the masseter muscle gained volume reduction
after using EMS. The muscle that most closely
adheres to the skin and the largest of the facialmuscles is the masseter muscle. The reduction
in masseter volume after using EMS makes theface slimmer. Therefore, it is considered thatthe use of EMS provided a facial treatment
effect. In addition, the loss of muscle volume
after EMS is not a loss of muscle mass itself. As
mentioned in the introduction, EMS promotes
muscle movement and contracts muscles. Muscle activation also has the beneﬁt of enrichingfacial expressions. Therefore, although themuscle volume is reduced, there is no healthproblem in using EMS and it can be used forbeauty.
In this study, the EMS facial equipment wasused only eight times in total. The volume of
the masseter muscle was reduced with thisrelatively small number of uses, suggestingthat this EMS facial equipment may be suitablefor use as a cosmetic device, inducing facial
treatment effects in a relatively short periodof time. However, when use of the EMS facial
equipment is discontinued, muscle contraction
is likely to return to its original state, leading
to the disappearance of the facial treatment
effect. Thus, it is likely to be necessary to use
the EMS facial equipment on a regular basis tocontinue the facial treatment effect. Importantly, some facial muscle rollers, cosmetics, andpharmaceuticals have been reported to affectmaterial
The effects of electrical muscle stimulation on facial muscles: Volume change of facial muscles measured with magnetic resonance imaging

facial expression. One previous study reported
that the use of facial muscle roller devices must
consider the facial muscles, and that training isrequired for safe use 12). In addition, rough skinand other side effects are induced by somecosmetics and pharmaceuticals. Because the
EMS facial equipment does not have a risk ofthese negative effects, facial treatment effects
can be obtained efﬁciently.
Overall, the current results revealed that the
EMS facial treatment device induced a facial
treatment effect in a relatively short period oftime. We describe future research topics below. The number of subjects in this study is
10 cases. Since the number of cases is small
in this study, we would like to increase thenumber of cases and obtain credible datawhen conducting further research. In addition,
the volume data used this time is the one thatsets the ROI for one person. Originally, it isappropriate to evaluate with a few people andperform calculation of intra-class correlation
coefﬁcient. However, it was too difﬁcult to set
the ROI for muscles, so the ROI setting was for
one person. We would like to create a manual
for muscle ROI setting and build a system thatcan be evaluated by multiple people. In addition, there is also fat in the muscle. EMS may
also be given the ability to burn fat. Therefore,
we would like to pursue a method that canevaluate facial treatment from the viewpoint of
fat using short TI inversion recovery images.
The current study targeted young women in
their twenties. In the future, we plan to evaluate whether the treatment effect varies acrossage groups. In addition, we plan to investigatechanges in the thickness of facial muscles
using an ultrasonic device, and to measurechanges in muscle hardness using shear wave

elastography. At the end, in this study, one
EMS device is used for evaluation. However,other manufacturers are also developing devices with EMS function. Since the principle of
EMS effect is the same even if the device is different and the treatment procedure is different,
it is considered that the same facial treatment
effect can be obtained. It is also necessary to
examine the effects of facial treatments on various devices.

5．Conclusion
The use of EMS facial equipment induced adecrease in masseter muscle volume measured
using T2WI of MRI. Therefore, it was suggested
that the use of EMS facial equipment promotes
the movement of facial muscles, reduces muscle mass, and has the effect of slimming theface. In addition, a facial treatment effect could
be obtained even with short-term use.

Acknowledgments
We would like to express our deep gratitude
to Soichi Tatsutani of Hitachi, Ltd. Healthcare Chubu/Hokuriku Branch, Nobuyuki
Arai of Suzuka University of Medical Science,
students of Muto Laboratory, and volunteers
for their cooperation in this research. We thank
Benjamin Knight, MSc., from Edanz Group(https://en-author-services.edanz.com/ac) for
editing a draft of this manuscript.

Conﬂicts of Interest
This research was supported by joint research funding from Mikimoto PharmaceuticalCO., LTD.

Arts and Sciences ◆ 53

References
1） S. Zhang, et al.: Fighting against Skin Aging: The Wayfrom Bench to Bedside. Cell Transplant, 27; 729-738,
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3） T. Kaneko, et al.: Effect of Improving Skin Quality by
Facial Equipment Using Radio Waves. Shinryo to Shinyaku (Med Cons New-Remed), 55; 787-793, 2018.
4） V. Esteve, et al.: The effect of neuromuscular electricalstimulation on muscle strength, functional capacityand body composition in haemodialysis patients.
Nefrologia, 37; 68-77, 2017.
5） N. A. Mafﬁuletti, et al.: Neuromuscular adaptations toelectrostimulation resistance training. Am J Phys Med
Rehabil, 85; 167-175, 2006.
6） General incorporated foundation Institute of Japan
Therapeutic Apparatus. http://nihondenshi.xsrv.jp/
hp/?page_id=964. Accessed November 15, 2020.
7） E. J. Choi, et al.: Effects of Electrical Muscle Stimulation on Waist Circumstance in Adults with Adbominal

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Obesity: A Randomized, Double-blind, Sham-Controlled Trial. JNMA J Nepal Med Assoc, 56; 904-911,
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8） ITO CO., LTD. Instruction manual for PEARL FACE
ESTHE Sonic EX.
9） Beauty Eos Inc. Kireinosennsei. https://kireinosensei.
com/1300113/. Accessed January 12, 2021.
10）K. Yamada, et al.: Difference of the Contrast between
CT and MRI: the Selection of the Alternative Imaging.
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11）K. Yamada, et al.: Technical parameters affecting image characteristics in in vivo MR microscopy of themouse. Vet Radiol Ultrasound, 43; 518-527, 2002.
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Arts and Sciencesmaterial

Received July 7, 2021 ; accepted November 7, 2021

Dementia disease classification of the statisticalanalysis images of cerebral blood f low SPECT
using deep learning
YAMAMOTO Yasushi1），SHIRAI Masato2），KATSUBE Takashi1），YOSHIZAKO Takeshi1），
UWABE Hoshio3），MIYAHARA Yoshinori3），KITAGAKI Hajime4）
1）Department of Radiology, Faculty of Medicine, Shimane University2）Interdisciplinary Faculty of Science and Engineering, Shimane University3）Department of Radiology, Shimane University Hospital4）Kobe City Nishi-Kobe Medical Center

Note: This paper is secondary publication, the ﬁrst paper was published in the JART, vol. 69 no. 837: 36-42, 2022.
Key words: GoogLeNet, AlexNet, Artiﬁcial intelligence, Grad-CAM, 3D-SSP【Summary】

Using the original deep learning model, we attempted to classify the following disease: AD, DLB, and normal
cognition, from the cerebral blood ﬂow SPECT 3D-SSP images. Then we compared it with the transfer learning of
GoogLeNet and AlexNet that was previously reported. Furthermore, we tried to visualize the accuracy of each analysis
by Grad-CAM. The accuracy was low in AD for AlexNet, and in DLB for GoogLeNet. We obtained stable results in theoriginal model. There were differences between the position and the size of the feature areas captured in each modelfrom the Grad-CAM images. The original model captured the hypovolemic region precisely.

Introduction
Recently, in the ﬁeld of radiographic images,
the clinical application of Artiﬁcial Intelligence(AI) has been rapidly growing, and many ofthem are reported in papers. Typical examples
are the detection of brain haemorrhage byhead CT scans 1), the detection of unruptured
aneurysms on the MRA 2), applications of noise
reduction technologies 3), or reconstruction
technologies 4) on Computed Tomography (CT)or Magnetic resonance imaging (MRI). As wehave shown, AI technology is used in many
ways. In 2019, the software, which allows us todetect a cerebral aneurysm on Magnetic resonance angiography (MRA), received regulatory
approval for the ﬁrst time in Japan. Turning tothe ﬁeld of nuclear medicine, it is reported thatan attempt to make images of CT scans from
Positron computed tomography (PET) images
and to use them for attenuation correction 5).
Iizuka and others classiﬁed dementia disease

from Three-dimensional stereotactic surface
projection (3D-SSP) 6) images made from cerebral blood ﬂow Single photon emission computed tomography (SPECT) with deep learning(DL), then they reported the scientiﬁc validityfrom the perspective of visualizations of thespeciﬁc hypovolemic regions 7). We, our group,
have been attempting the classiﬁcation of dementia disease by our original deep learningmodel with 3D-SSP images made from cerebral
blood ﬂow SPECT images 8). Moreover, with anapplication of the notion of simulation training
data stated by Uwabe 9), we have veriﬁed andreported the classiﬁcation of dementia disease 12, 13) by well-recognised AlexNet (A.N) 10)
and GoogLeNet (G.N) 11). This time, we assessed the results of identiﬁcation accuracy calculations by O.N from data groups which are
the same as the reports from by A.N and G.N.
Additionally, using Gradient-weighted Class
Activation Mapping (Grad-CAM) 14) ; one oftechnologies for visualizing Convolutional neuArts and Sciences ◆ 55

ral network (CNN), we compared O.N with
G.N and A.N to clarify their differences by
Grad-CAM heat map images.

1. Methods
1-1 Used Models (A.N, G.N, O.N)

O.N is composed of 4 layers of CNN and 3
layers of Pooling. We showed detailed settings
in Fig.1. We utilised Matlab 2019b (Mathworks
Company), Deep learning toolbox, Image Processing Toolbox, Computer vision toolbox,
and Parallel computing toolbox in the analysis.
We also described the details of G.N and A.N
as comparison objects in References 10, 11).
1-2 Making image data

The images we utilised in the analysis are
3D-SSP Z-score maps gained from N-Isopropyl-p-[123I] Iodoamphetamine (123I-IMP) 167
MBq cerebral blood ﬂow test. Moreover, we
also utilised Discovery NM/CT 670pro, 3D-OSEM methods (subsets 10, iterations 6) for im-age reconstruction, Dual energy window methods, CT based Attenuation correction methods.
For 3D-SSP analysis, we utilised the Normal
Database of Shimane University. We showed
the standard output images from 3D-SSP in
Fig.2 (C). They were images of a human brain
taken from eight different directions: the anterior surface, the posterior surface, the left lateral surface, the right lateral surface, the left
medial surface, and the right medial surface.
The original sizes were 890 × 660 pixels. However, we adjusted the sizes for 224 × 224 pixels
in order to assess with G.N and A.N. (Supplementary information: the size- 224 × 224 pixels is the same size for A.N. The size for G.N is
227 × 227 pixels.) Then in order to avoid lossof detection accuracy by image reduction in
the hypovolemic regions (Z-score description
regions) as targets, we chose the images from
4 different directions (the left and right lateralmedial surface sides) from the images from 8
directions as shown in Fig.2 (D). Why we chosethese images is it is important to discern the

(A)

(B)

Image input layer(1)Input Size

Convolution 2Dlayer(6)[224,224,3]

Convolution 2Dlayer(2)Channels

16

Batch normalization layer(7)(11)(15)Filter Size
Channels
Stride

[3,3]
8
[1,1]

Convolution 2Dlayer(10)Channels
Convolution 2Dlayer(14)32

Paddingzero padding

Channels

64

WeightsInitializer

XavierFull connected layer(17)Batch normalization layer(3)(7)InputSize

50176

ReLU layer(4)(8)(12)(16)

OutputSize

3

Max pooling 2Dlayer(5)(9)(13)Bias[-0.04;-0.02;0.06]

PoolSize
StrideWeightsInitializer

Xavier

[2,2]
[2,2]

Fig.1 Configuration diagram and parameters of the original model．
It comprises 4 convolution layers and 3 pooling layers.（A: Conﬁguration diagram created with deep network designer inmatlab.）56 ◆ Journal of JART English edition 2023

material
Dementia disease classification of the statistical analysis images of cerebral blood flow SPECT using deep learning

typical hypovolemic regions for Alzheimerʼsdisease (AD) or Dementia with Lewy bodies(DLB). Moreover, we regenerated all these images to ensure that they are placed on thesame coordinates. To analyse, we need three
data groups: Training, Validation and Test.
About Training, we utilise 3D-SS images madefrom the simulation data of SPECT imitating
the speciﬁc hypovolemic of AD, DLB as well as
the report from Uwabe 8). The SPECT data usedas the basis for the simulation data were 123IIMP healthy data collected in 2013 for the Normal database (28 subjects (15 males: 67.7 ± 6.2
years, 13 females: 68.1 ± 5.7 years)), whichwere transformed into Montreal neurologicalinstitute (MNI) brain coordinates using statistical parametric mapping 8 (SPM8) 15). The results of this study were used to determine theneurological volume of interest (VOI) in thebrain, and the neurological VOI was estimateda R.Latc R.Med(D)busing the Voxel-based analysis-stereotactic extraction estimation (vbSEE) 16) Level3 after conversion to Montreal neurological institute(MNI) brain coordinates using SPM8. The neurological VOI regions were utilised, including
the angular gyrus, superior parietal lobule, inferior parietal lobule and superior marginal gyrus, which are located in the left and right parietal lobule regions, plus six regions of theposterior cingulate gyrus and precuneus in AD,
and the superior occipital, middle and inferior
occipital gyri, which are located in the occipital
lobe region, plus the wedge, which is the primary visual cortex, and the cuneus in DLB.
Masked images were generated by multiplying
the base image with masked data in which thecounts in each mask were progressively reduced to 35%, 30%, 25% and 20%, to generatevarious patterns of dementia SPECT data. We
set the threshold value of the Z-score (Fig.2 (C)L.Lat

d L.Med
(E)

(F)

(H)

(G)

(I)

(C)
Fig.2 AD and DLB simulation images and the NC image used for the training.
（C）Original image of 3D-SSP,（D）AD simulation data created from C（⇒：-35%）,（E）Simulation image of AD（⇒：-20%）,（F）Simulation image of AD（Changed reference region from GLB to THL）,（G）Simulation image of AD（Changed Z-scorethreshold）,（H）Simulation image of DLB,（I）NC image.

Arts and Sciences ◆ 57

②) from the Z-score map of each hypovolemia

gained from these 3D-SSP analyses. Then, we
made a simulated Z-score map of each 341
cases of AD, and DLB to make normalised sitesetting (whole brain: GLB, thalamus: THL,
pons: PNS, cerebellum: CBL③) and the settingof threshold value we have stated before variable in each image. About (D) (①), we reduced
35% of the count of a speciﬁc hypovolemic region of AD, and additionally, made it by extracting 4 directions. For (E), we reduced 20%of counts for a speciﬁc hypovolemic region. In
the case of (F), a reference area was changed
from GLB to THL. Moreover, (G) shows a caseof each Training in which its threshold value
setting of (E) was changed. In that way wehave written, we multiplied simulated Trainingof AD, and DLB to 341 cases from the 28 casesof healthy ones. Now we must mention that
we excluded the reference area which hardly
detected AD, and DLB even though they wereseen by Diagnostic Radiologist with more than
20 years of experiences who were good at diagnosing dementia disease. We showed thedetailed data breakdowns in the references 10).
Fig.2 (H) shows one case of DLB, and ( I ) shows
one case of Training of N.C. For the Test, wechose 20 cases with each disease: AD, DLB,
and NC which were diagnosed by Diagnostic
Radiologist from patientsʼ Z-score maps madefrom patientsʼ data who were taken 123I-IMP cerebral blood ﬂow SPECT. Additionally, we adopted 2 images which were best seen fromnormalised sites. Finally, we adopted 40 cases.
Patientsʼ background; diagnosed with AD, Age(y) ; 72.3 ± 3.8, M/F; 15/5, DLB 80.5 ± 7.3,
M/F; 10/10, NC 67.8 ± 15.4, M/F; 6/14. For Validation, we utilised 28 cases by ﬁxation analysis. In these 28 cases; a reference area is GLB
set from Training of AD, DLB, NC, a lower
threshold limit setting is 1.0, and an upper
threshold limit setting is 5.0.
1-3 Evaluation & Assessment

For diagnosis with AD, DLB, or NC, postu-

58 ◆ Journal of JART English edition 2023

lated that diagnosis by Diagnostic Radiologist
is correct, we assessed it in the 4 sections; Accuracy (the rate of the correct data), Precision(the rate of true positive in the total positives),
Recall (that shows sensitivity and statisticalpower), and F-measure (that means overall indicate value.) If we calculate them by thesefactors: True Positive (TP), False Positive (FP),
False Negative (FN), and True Negative (TN),they are Accuracy = TP + TN/Total, Precision =TP/TP + FP, Recall = TP/TP + FN, F-measure =2 × (Precision × Recall)/(Precision + Recall).
We assessed each indicator value by mean value of 20 timesʼ trials and standard deviation.
Subsequently, we also visually assessed how
the hypovolemic regions determined the classiﬁcations, by heat map images made by GradCAM. Furthermore, we conducted this research
after gaining the approval from Ethics Committee at Shimane University, Faculty of Medicine.

2. Results
Fig.3 is a candlestick chart that shows Recall

by pathological types in G.N and A.N from thealready submitted reports 10, 11) with added theresults of O.N. From Fig.3 and Table 1, the results of ADʼs recall are O.N (0.83 ± 0.09) ＞
G.N (0.82 ± 0.12) ＞ A.N (0.52 ± 0.12), the results of DLBʼs are O.N (0.85 ± 0.05) ＞ A.N(0.74 ± 0.09) ＞ G.N (0.42 ± 0.12), in the caseof NC, they are O.N (0.86 ± 0.06) ＞ G.N(0.78 ± 0.08) ＞ A.N (0.76 ± 0.06). In the caseof AD, there are no signiﬁcant differences between G.N and O.N. However, others show agreat value of O.N with signiﬁcant differences,additionally, in the sections of Training andValidation of O.N, many index values were 1.0.
Fig.4 shows the data that are Grad-CAM heat
map images of A.N and G.N quoted from References 11) and their images are added with theresults of O.N. There are differences between
the size of regions or the shape of the distribution that is “heat-mapped” by each analysis
model. In each model of AD (J, K, L), bilateralmaterial
Dementia disease classification of the statistical analysis images of cerebral blood flow SPECT using deep learning

3. Consideration

Fig.3 The graph shows the recall in each modelby disease type．
In the AD group, G.N and O.N showed high values,
and there was no significant difference in them. In the
DLB group, O.N showed the highest value, which
was significantly different from those of G.N and A.N ．
Additionally, O.N was high in NC, and it differed from A.N
and G.N．

posterior cingulate gyrus, precuneus, temporal
regions, and parietal lobe were heat-mapped.
In the models of DLB (M, N, O), bilateral temporalis and occipital lobe were heat-mapped.
Lastly, in the case of NC (P, Q, R), non-hypovolemic regions were.

First, we will state some things for the simulated training data of O.N; Accuracy of Training
in Table 1 is all types of disease 1.0 and it consists of the different images pattern (different
feature images) from AD and DLB. Furthermore, seen from the results of Validation, we
can state it can precisely classify the disease by
3D-SSP images if these images are typical patterns of them. As we stated, we determinedthat these training data groups were appropriate for this research. From ADʼs heat map in
Fig.4 (J, K, L), in A.N and G.N, the regions
whose Z-scores are high are correctly captured. However, there are some cases which
are not correctly classiﬁed; the cases which theheat map was widely spread (J) and extended
into the occipital lobe which the speciﬁc hypovolemic regions for DLB like R.Med. Or thecases that parietal lobe was weakly heatmapped like L.Lat (K). Given these cases, we
could assume that the two conditions in order
to correctly classify; Z-score description areas
are limited to the speciﬁc areas of AD and DLB.
Furthermore, Z-scores are high. To classify thegiven diseases properly, these two conditions
must be fulﬁlled. If we take a look at the occipital lobe of DLB in Fig.4 (M, N, O), in O.N,
A.N, and G.N, they were strongly heat-mapped

Table 1 Recall，Precision，and F-measure in O.N analysis method were calculated separately
for AD，DLB，and NC．
Data type

Test

Training

Validation

Evaluation
method

AD

DLB

NC

Recall0.83 ± 0.09

0.85 ± 0.05

0.86 ± 0.06

Precision

0.84 ± 0.05

0.83 ± 0.06

0.87 ± 0.06

F- measure

0.83 ± 0.04

0.83 ± 0.04

0.86 ± 0.03

Recall

1.00

1.00

1.00

Precision

1.00

1.00

1.00

F- measure

1.00

1.00

1.00

Recall1.00

1.00

0.98 ± 0.02

Precision

0.98 ± 0.02

1.00

1.00

F- measure0.99 ± 0.01

1.00

1.00

Accuracy

0.84 ± 0.02

1.00

0.99 ± 0.01

Table 1
Arts and Sciences ◆ 59

Fig.4 Heat map of A.N, G.N, and O.N analysis images classified as AD, DLB, and NC by matching with theradiologistʼs reading results．
Heat map of images classiﬁed as（J）AD,（M）DLB, and（P）NC by A.N. Heat map of images in which the same image isclassiﬁed as（K）AD,（N）DLB, and（Q）NC by G.N. Heat map of images in which the same image is classiﬁed as（L）AD,（O）DLB, and（R）NC by O.N.（⇒）indicates a heat map region that correctly recognizes the speciﬁc blood ﬂow reduction
region in AD and DLB, and NC heat map region without blood ﬂow reduction.

in R.Med, additionally, they were weakly donein L.Med. For these facts, we can assume thatthe “High” and “Low” of the Z-score are recognised as one of the features as well as (K) L.Lat.
Also, in (N) of G.N, the left and right occipital
lobes were captured as one large region. So
that made the centre of the heat map not located in the images. We can also see someother cases which have the same tendencies
that we stated, so we couldnʼt carry out thefeature detections that were limited in the regions of Z-score by the transfer learning whose
conﬁguration conditions were not changed forthe analysis model. For NC in Fig.4 (P, Q, R),they didnʼt have any speciﬁc hypovolemic regions, so we can determine these images are
the ones in which the entire images are heatmapped, and we cannot ﬁnd the feature regions. Fig.5 (S, U, X) shows the images of each60 ◆ Journal of JART English edition 2023

model whose classiﬁcations differ from the diagnosis by Diagnostic Radiologist. (S) is thecase DLB was classiﬁed as AD by A.N. Heat
map extended to the occipital lobe (⇨) whichis the hypovolemic region of DLB. That madethe classiﬁcation wrong. Then we researched
the images of AD Training in A.N, there wereimages which were heat-mapped in Z-scorelower than the hypovolemic regions shown in(M). In order to distinguish it from DLB, weneed to reconsider the addition of the training
data which are with the feature of AD and low
Z-score exists in the occipital lobe. (U) is thecase in which DLB was classiﬁed as AD by
G.N, the occipital lobe is weakly heat-mapped,
and the cingulate gyrus regions were strongly
captured. (V) shows one of the cases of DLB
Training in G.N. As well as in Fig.4 (N), it was
widely heat-mapped with the occipital lobe ofmaterial
Dementia disease classification of the statistical analysis images of cerebral blood flow SPECT using deep learning

Fig.5 Heat map of images in which the radiologistʼs reading results and classification results did not match．
（S）In A.N，AD was erroneously classiﬁed as DLB.（U）In G.N，DLB was erroneously classiﬁed as AD.（X）In O.N，DLB waserroneously classiﬁed as AD.（⇒）indicates the heat map area that caused the erroneous classiﬁcation of AD and DLB.（T）ADin A.N（V）DLB in G.N（Y）AD in O.N, heat map area of each train data.

R.Lat and L.Lat as one of the features. For this,we need to add the data on which one side of
the Z-score (not bilateral symmetry) is low for
Training. (X) is the case in which AD was classiﬁed as DLB by O.N; blood ﬂow was strongly
reduced in the cingulate gyrus. Diagnostic Radiologist could recognise that was because of
the effects of a high Z-score. However, O.N
could not. (Y) shows one of the cases of AD
Training of O.N. O.N can recognise slight Zscore and differences in position. So, we assume that we can correspond to it by the addition of training data like (X).
Generally speaking, given models whichhave deep layered like G.N have a lot of parameters for learning objectives, we need toverify it with an increase in the numbers of
training data. A.N has one more convolutional
layer compared to O.N. Each convolutional
layer has many channels, so we need to give a
lot of data for it as well as G.N. Also, we utilised Local Response Normalization for a normalisation process. However, in O.N, by use of

Batch Normalization, we can keep the changes
in the internal variable distribution small andreﬂect the learning results to the estimated results more precisely. In the case we have givenin this research: a small variation in characteristics of training data, the number of classiﬁcations is small, less geometrical differences as
the whole images, what difference are only Zscoreʼs distribution geometry and Z-score itself,
we could classify by simple models like O.N.
However, if we enrich the training data andutilise parameters that it appropriates for eachmodel, the results can differ.

4. Conclusion
By using deep learning, we tried the classiﬁcations of dementia disease by aspects fromblood ﬂow SPECT and 3D-SSP images. The
Training data we use were 341 data made fromsimulations. Cases are each 40 data with AD,
DLB, and no abnormality. We utilised 4 layersof CNN and O.N with 3 layers of Pooling layers
Arts and Sciences ◆ 61

as analysis models. We could classify these diseases with more than 80% of accuracy against
the diagnosis by Diagnostic Radiologist. It
showed a better result than the transfer learnings of A.N and G.N that we previously reported. Compared to the visualizations of feature areas by Grad-CAM, O.N took more conﬁned speciﬁc hypovolemic areas than A.N and
G.N. In this case with a fewer number of clas-

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Arts and Sciencesmaterial

Received May 23, 2021 ; accepted December 2, 2021

Research on eye lens exposure doses and exposure
management for physicians involved in Interventional Radiology
ARAI Kazumasa1），WATANABE Hiroshi 2），MEGURO Yasuhiro3），KITAYAMA Sanae4），
YABE Satoshi 5），SASAKI Takeshi 6），HASEGAWA Takeshi 7），FUKUZUMI Toru 8），
KAWASAKI Hideo9），SATO Yoichi 10）1）Department of Radiological Technology, Japanese Red Cross Musashino Hospital2）Department of Radiological Sciences, Faculty of Health Science and Technology, Gunma Paz University3）Department of Radiological Technology, Hokkaido Industrial Health Management Fund
4）Department of Radiological Technology, Japanese Red Cross Saitama Hospital5）Department of Radiology, Central Medical Division, Koshigaya Municipal Hospital6）Department of Radiological Technology, Ageo Central General Hospital
7）Department of Radiological Technology, Tsuchiura Kyodo General Hospital8）Department of Radiology, Dokkyo Medical University Hospital9）Department of Radiology, Juntendo University Hospital10）Department of Radiological Technology, Kofu-Kyoritsu Hospital

Note: This paper is secondary publication, the ﬁrst paper was published in the JART, vol. 69 no. 840: 32-41, 2022.
Key words: Medical exposure, Medical Law Enforcement Regulations, Radiation protection, Exposure management,

Lens exposure dose
【Abstract】

The Ministry of Health, Labour and Welfare revised the “Regulation on Prevention of Ionizing Radiation Hazards,”
which was established based on the Industrial Safety and Health Act, and implemented from April 1, 2021, withparticular emphasis on the reduction of the equivalent dose limits for eye lens exposure. A study group was formed
to review the exposure limit for the eye lens in Japan; the report of the study group stated that many medical
workers experience radiation exposure to the eye lens, and that appropriate individual exposure doses have notbeen measured. We conducted a fact-ﬁnding survey to investigate radiation exposure to physicians belonging to theinterventional radiology department at different medical institutions. Our results clearly indicate that by considering
the standards for lowering the dose limit, some physicians will be exposed to radiation exceeding the newly
recommended dose limits, and that even currently, the exposure dose for physicians is not being measured correctly
at medical institutions.

Introduction and Purpose
The partial revision of the Regulations for thePrevention of Ionizing Radiation Hazards in
the Industrial Safety and Health Act was implemented from April 1, 2021. What emphasized
here is to reduce the equivalent dose limit for
the lens of the eye. The main points of the revised ministerial ordinance are (1) 3 mm dose
equivalent dose of the lens equivalent dose
was added to the conventional measurementof the 1 cm dose equivalent and the 70-micrometer dose for the measurement of the doseby external exposure, (2) the equivalent dose
limit to the lens of the eye for medical staff andetc. engaged in work dealing with radiation
was lowered to 50 mSv from 150 mSv per year,
100 mSv dose limit for each period divided
into ﬁve-year periods was also added startingfrom April 1, 2021.
According to the Kunugita Document 3 of
the Ministry of Health, Labour and Welfareʼs
2nd “Study Group on Lens Exposure Limit,”
medical professionals are the most common
category of radiation workers who are subject
to exceeding the dose limit with the reviseddose limit values. Among the 511,499 radiation
workers in the 2017 ﬁscal year, except foratomic, decontaminations and reactor decommissioning workers, the annual equivalent lensArts and Sciences ◆ 63

dose for most of them was less than 20 mSv
limit, but 2,236 were exposed to more than 20
mSv limit per year. Of the 364,740 medical staff
employed in general healthcare in ﬁscal 2017,
2,221 were exposed more than 20 mSv equivalent dose to the lens of the eye, this number
comprised 0.6% of the total 1). (369 medical
staff in general healthcare exceeded 50 mSv,
0.1% of the total). More than 99% exceeding 20
mSv are medical professionals, therefore themedical ﬁeld is the most concerned to consider
reducing of the equivalent dose limit for lensof the eye mandated by the revision of the law.
In the Kunugita Document 5, the physicians
exposed to more than 20 mSv to lens of eye
are cardiologists, gastroenterologists/gastroenterological surgeons, radiologists, and orthopedic surgeons in the order of exposure dosefrom higher to lower, and for physicians those
exposed to 50 mSv or more were gastroenterologists, orthopedists, neurosurgeons, and cardiologists as well 2). Furthermore, in Kunugita
Document 4 of the 6th Study Group on Lens
Exposure, there are some cases where appropriate dosimetry was not performed 3). In earlier literature, Meguro et al. pointed out thatﬂuoroscopy doses in Interventional Radiology(IVR) are left to the determination and discretion of the physician, and it is not easy to evaluate excess exposure 4) in the study of the necessity of Ministerial Ordinance Guidelines for
the Revision of the Enforcement of Regulationsof the Medical Law to be enacted in 2020. Afterthe implementation of the revised ministerial
ordinance, it is expected that radiation exposure management for physicians who comply
with the dose limits will become more difﬁcult
than before the implementation of the revised
ordinance.
The purpose of this study was to clarify thecurrent problems of medical institutions by investigating the number of physicians who areexposed to excess dose limit for lens of eye inaccordance with the revised ministerial ordinance, the accurate exposure measurement

64 ◆ Journal of JART English edition 2023

status of physician personal dosimeters, theuse of X-ray protective equipment of physicians involved in eye lens exposure reduction,
the use and availability of X-ray protective
glasses, the management status for the occupational exposure as well the patient exposure
from the actual situation of radiation exposure
management at hospitals nationwide.

1．Methodology
1-1 【Investigation】

We conducted a questionnaire survey bysending a survey request on eye lens exposure
doses and exposure management of physicians
involved in IVR by e-mail and obtaining responses through Google Form as the target of
total of 308 medical institutions, covering 217
medical institutions to which members of theJapan Society of Radiation and Public Safety
belong (excluding 12 Red Cross hospitals employing members of the Japan Society of Radiation and Public Safety) and 91 national Red
Cross hospitals. The period was from October
1, 2020 to January 31, 2021.
The survey consisted of the facility name, thename and e-mail address of the respondents,
the total annual eye lens exposure dose ofphysicians recorded at each medical institution
for the one year of FY2019 and the total eyelens exposure dose in the period FY2015 to
FY2019, the measures of personal dosimeters,
the use/availability of lens dosimeters, the status of use of X-ray protective equipment, thenumber and use of X-ray protective glasses,
and the arrangements at hospitals to manage
patient and operator exposure.
1-2 Ethical Considerations

In September 2020, this research was approved as clinical research after an ethics review by the Clinical Research Ethics Review
Committee of Musashino Red Cross Hospital(approval number: Musashi So. 698).

material
Research on eye lens exposure doses and exposure management for physicians involved in Interventional Radiology

2．Results
2-1 【Basic Information】
2-1-1 Response rate and respondents

The response rate was 24% (74/308) from 74
facilities in Japan. The response rate was 17%(37/217) from facilities with members of theJapan Society of Radiation and Public Safety,
and the response rate of Red Cross hospital
facilities was 41% (37/91). There were 74 respondents, all radiological technologists: general managers and chief technicians 26%(19/74), section managers 24% (18/74), assistant managers 27% (20/74), and not in management position 23% (17/74).
2-1-2 Number of beds in the responding facilities

The numbers of beds in the responding facilities were as follows: 600 beds or more (24%,
18/74), 300~599 beds (47%, 35/74), 100~299
beds (16%, 12/74), and fewer than 100 beds
(12%, 9/74) (Fig.1).

gastroenterological surgeons, and orthopedic
surgeons mainly performing IVR in X-ray ﬂuoroscopy room.
The survey results showed that the numberof medical institutions and physicians employed as cardiologists was 459 at 58 medical
institutions, 131 diagnostic radiologists at 47
institutions, and 184 neurosurgeons at 49 medical institutions. There were 456 gastroenterologists at 61 medical institutions, 388 gastroenterological surgeons at 59 medical institutions
and 364 orthopedic surgeons at 58 medical institutions (Fig.2).
For surveys of the classiﬁcation of physiciansby department, the ratio (%) is shown using
the number of medical institutions with thenumber of physicians as the denominator. For
other questions unrelated to the classiﬁcationof physicians by department, the ratios (%) are
shown using the 74 of the valid facility responses as the denominator.
2-1-4 Percentage of full-time physicians at facilities by department

2-1-3 Survey of the number of physicians bydepartment in the medical institutions
Physicians by department were classiﬁed
into the following six departments with eyelens exposure dose based on previous literature 2): cardiologists, radiologists, and neurosurgeons performing IVR; gastroenterologists,

Figure 3 shows the ratio of physicians employed in each department at the responding
facilities.
2-2 【Lens exposure】
Table 1 shows the results of a survey of thenumber of physicians who exceed the dose

Number of beds

912%

Number of physicians

n=74

364
18%

18
24%

12
16%

≥600
300-599
100-299
<100

131
7%

388
20%
184
9%

35
47%

Fig.1 Number of beds in participating medical
institutions

n=1982

459
23%

Cardiologists
Radiologists
Neurosurgeons
Gastroenterologists
Gastrointestinal surgeons
Orthopedic surgeons

456
23%

Fig.2 Number of physicians by specialty atparticipating medical institutions
Arts and Sciences ◆ 65

Cardiologists

NeurosurgeonsRadiologists
n=74

16
22%

25
34%

27
36%

49
66%

47
64%

58
78%

Gastroenterologists

Gastrointestinal surgeons
n=74

13
18%

n=74

n=74

n=74

15
20%

61
82%

Orthopedic surgeons
n=74

16
22%
58
78%

59
80%

Number of hospital employees
not hospital employees

Fig.3 Percentage of medical institution specialists
Table 1 Exposure to eye lens of physicians
Total number
Cardiologists Radiologistsof physicians（n=1982）（n=459）（n=131）≥ 20 mSv within

one year≥ 100 mSv in a
5-year period

Neurosurgeons

Gastroenterologists（n=184）（n=456）

Gastrointestinal Orthopedic
surgeons
surgeons（n=388）（n=364）69（3.5）43（9.4）3（2.3）

0（0.0）

14（3.1）5（1.3）

4（1.1）

57（2.9）37（8.1）3（2.3）

1（0.5）

14（3.1）2（0.5）

0（0.0）

Unit：Number of physicians（%）

limit when the equivalent dose limit of exposure was reduced.
2-2-1 Table 1 shows the number of physi-

cians exposed to equivalent eye lens exposure
dose of 20 mSv or more in FY2019, and total
eye lens eye exposure dose of 100 mSv or
more in the 5 years from FY2015 to FY2019.
According to the results, 9% of cardiologists,
3% of gastroenterologists and 2% of radiologists
had exposed more than 20 mSv equivalent eyelens exposure dose for one year. In addition,
8% of cardiologists, 3% of gastroenterologists,and 2% of diagnostic radiologists had been
exposed to high rates of total lens of the eye
exposure more than 100 mSv of over 5 years.
2-3 【Management for personal dosimeters】

Appropriate use of personal dosimeters en-

66 ◆ Journal of JART English edition 2023

ables accurate exposure evaluation. Table 2
shows the results of surveys on the measurement status of non-uniform exposures, the actual use of personal dosimeters and the measurement positions of personal dosimeters.
2-3-1 Survey of the distribution of personal dosimeters to physicians by department at
each medical institution (response to
non-uniform exposures)
Table 2 shows the results of the distributionof personal dosimeters to physicians by department. The distribution of personal dosimeters was surveyed by dividing the facilities
into the following three categories: facilities
that distribute two dosimeters that can measure
non-uniform exposures, one for the head andneck and the other for the chest and abdomen,
facilities that distribute only one dosimeter thatmaterial
Research on eye lens exposure doses and exposure management for physicians involved in Interventional Radiology

Table 2 Use of personal dosimeters

Number of physicians
Number of medical
institutions

Cardiologists

Radiologists

Neurosurgeons

Gastroenterologists

Gastrointestinal
surgeons

Orthopedic
surgeons（n=459）（n=131）（n=184）（n=456）（n=388）（n=364）（n=58）（n=47）（n=49）（n=61）（n=59）（n=58）

Dosimetry use of uneven exposure in medical institutions
Personal dosimetermeasure in 2 places
Personal dosimetermeasure in 1 place
No personal
dosimeter

53（91）

42（89）

44（90）

55（90）

37（63）

41（71）

4（7）

5（11）

4（8）

5（8）

14（24）

14（24）

1（2）

0（0）

1（2）

1（2）

8（14）

3（5）

Unit：Number of medical institutions（%）
Percentage of dosimetry performed by physicians using personal dosimeters≥ 80% used

311（68）118（90）113（61）

241（53）141（36）163（45）≥ 50 ‒ < 80% used

35（7）63（14）
50（11）

2（2）
3（2）
8（6）

15（8）
47（26）
9（5）68（15）
110（24）
37（8）

30（8）
146（38）71（18）

48（13）
100（27）53（15）

374（82）

121（92）128（70）283（62）180（46）201（55）11（2）74（16）

0（0）
10（8）

4（2）
52（28）

25（6）148（32）37（10）
171（44）26（7）137（38）< 50% usedunknown

Percentage of accurate dosimetry by physicians
accuratemeasurements
wrong measurements
unknown

Unit：Number of physicians（%）

cannot measure non-uniform exposures andfacilities that do not distribute dosimeters.
When non-uniform exposures could not bemeasured, accurate measurement of eye lens
exposure would be impossible. Based on this,when the results are summarized by physician
and department, about 10% of facilities are unable to measure non-uniform exposures aboutcardiologists, diagnostic radiologists, neurosurgeons and gastroenterologists. Approximately
30% of facilities with only one distribution arrangement and those without distribution wereunable to measure non-uniform exposures. It
was shown that the proportion of physicians
who performed procedures in the X-ray ﬂuoroscopy room was higher in facilities where
non-uniform exposures could not be measured.

by dividing each department into three categories depending of the ratio of the number ofphysicians during the IVR treatment and examination: more than 80% of physicians wears
personal dosimeters, from 50% or more to lessthan 80% wears and less than 50% wears.
These results suggest that personal dosimeters are not worn in the working environment
where they should be worn. The percentagesof physicians wearing personal dosimeters byeach department are as follows: diagnostic radiologists (> 90%), gastroenterologists (36%),orthopedic surgeons (45%), gastroenterologists(53%), neurosurgeons (61%) and cardiologists(68%). These showed that the measured radiation values with personal dosimeters were inaccurate and underestimated.
2-3-3 Survey of the mounting position of per-

2-3-2 Survey on the actual use of personal dosimeters by physician and department

sonal dosimeters for the head and neckfor physicians by department(actual usage of personal dosimeters)

Table 2 shows the results of a survey of theTable 2 shows the results of a survey on themounting position of the personal head andneck dosimeters for physicians by department.
Physicians were classiﬁed into three catego-use of personal dosimeters by physicians ineach department. The survey was conducted

Arts and Sciences ◆ 67

ries: physicians wearing head and neck dosimeters in the correct position, physicians wearing the dosimeters in the wrong positions, andphysicians with the position unknown.
The percentages of physicians wearing personal dosimeters in the wrong positions byeach department are as follows: gastroenterological surgeons (10%), orthopedic surgeons(7%), gastroenterologists (6%), neurosurgeons(2%), cardiologists (2%), and radiologists (0%).
This shows that the physicians who performthe procedures in the X-ray ﬂuoroscopy room
often make mistakes in the mounting positionof the dosimeters.
2-3-4 Survey of the wrong measurement positions of personal dosimeters for the head

2-4 【X-ray protection】

The use of X-ray shielding plates, protective
cloth and X-ray protective glasses is important
for reducing the eye lens exposure dose. Fig.5
shows the results of a survey on the use of Xray protection in each facility.
2-4-1 Survey on the use of ceiling shielding
plates in angiography rooms for different
clinical procedures

To reduce the exposure to physicians, we surveyed the use of ceiling shielding plates used inangiography rooms for the following ﬁve procedures: transcatheter arterial chemoembolization of hepatic artery (TACE), percutaneous
coronary intervention (PCI), peripheral angioplasty (endovascular treatment: EVT), catheterand neck (measurement positions of personal dosimeters)

A survey of the wrong measurement posiLens personal dosimetertions of personal dosimeters for the head andneck was conducted. The total number of re7
n=74
9%
sponses was 19 cases. The most common position was the chest pocket inside the X-ray proIn use
tective clothing (47%, 9/19), followed by outNot in use
side on the chest of the X-ray protective clothing (21%, 4/19), outside on the back of the X67
ray protective clothing (16%, 3/19), on the91%
back of the headpiece of the hat (5%, 1/19),
reversed wearing from head and neck to chest
Fig.4 Use of dosimeters for the eye lens exposureand abdomen and vice versa (5%,at participating medical institutions
1/19), and wearing for chest and< 50% used
≥ 80% used
≥ 50 - < 80% used
abdomen but not on the head-neck
Other protections
Do not have protections(5%, 1 /19).
2-3-5 Survey on the use of special

2

30

ABL

34

Neuroendovascular therapy

22

35

ERCP
0%

10%

20%

30%

40%

50%

60%

70%

(n=51)

41(n=37)

11

3 1 (n=49)

26(n=65)

80%

90%

Fig.5 Usage of X-ray protective equipment

68 ◆ Journal of JART English edition 2023

(n=56)

12

8

31

EVT

1 (n=55)
4

8

44

PCI

eye lens dosimeters

A survey of the use of special eyelens dosimeters was conducted.
Nine percent (7 of 74) of facilities
used special eye lens dosimetersand 91% (67/74) did not (Fig.4). At
present, many facilities do not use
special eye lens dosimeters.

9

10

35

TACE

100%

material
Research on eye lens exposure doses and exposure management for physicians involved in Interventional Radiology

myocardial ablation (radiofrequency catheter
ablation: ABL i.e. shortened form of RFCA), andcerebrovascular treatment (cerebral aneurysm
coil embolization, arteriovenous malformation
embolization etc.). The survey results are shownin Fig.5. The use of ceiling shielding plates was
divided into four frequencies: used in morethan 80% of procedures in all treatments, usedin 50% to 80% of procedures in all treatments,
used in below 50% of procedures in all treatments, and shielded by another shielding method such as a shielding box.
The procedures where the use of ceilingshielding plates was below 50% were as follows: EVT (23%), TACE (16%), and PCI (7%).
When we compared the facilities in which the
cardiologists were exposed to 100 mSv or morewith the facilities where the ceiling shielding
plates use in PCI, EVT, and ABL was 50% to
80% and below 50%, 33% (4/12 facilities) were
the same facilities. Similarly, we compared thefacilities where the diagnostic radiologists were
exposed to 100 mSv or more with the facilities
where the ceiling shielding plates use in TACE
was 50% to 80% and below 50%, and 33% (1 of
3 facilities) was the same facilities.
2-4-2 Investigation of the use of X-ray protective
cloths when performing endoscopic retrograde cholangiopancreatography (ERCP)
including crushing gallstones endoscopically and lithotripsy

To reduce the exposure to physicians, wesurveyed the use of X-ray protective cloths

during ERCP (treatment and contrast examination). The survey results are shown in Fig.5.
The use of X-ray protective cloths during ERCP
was classiﬁed into four frequencies: used in
more than 80% of procedures in all treatments
and contrast examinations, 50% to 80%, below
50%, and zero X-ray protective cloths. Abouthalf (47%) of facilities with ERCP have X-ray
protection for physicians, but 40% of facilities
do not offer X-ray protection measures forphysicians because they have no X-ray protective cloths. When we compared the facilities
that did not have X-ray protective cloths withthe facilities where the gastroenterologists
were exposed to 100 mSv or more, 43% (3/7
facilities) were the same facilities.
2-4-3 Survey about the availability of X-ray protective glasses in each radiological roomsof respective facilities

To reduce the eye lens exposure to physicians, we surveyed the availability of X-ray
protective glasses in the imaging facility. The
number of X-ray protective glasses for physicians managed by hospitals was the number ofglasses shared with other professions andglasses purchased by individuals. Table 3
shows the results of the survey on the availability of X-ray protective glasses in the angiography rooms and X-ray ﬂuoroscopy rooms.
The average number of X-ray protective glasses per section was 5 for angiography and 2 for
X-ray ﬂuoroscopy rooms. There were more Xray protective glasses in the angiography

Table 3 Availability of X-ray protective glasses in institutions
Number of X-ray protective glasses

Number of rooms

Number of glasses per room

Angiography room

288

62

5

X-ray ﬂuoroscopy room

120

72

2

Table 4 Wearing rate of X-ray protective glasses by specialty
Cardiologists

Radiologists≥ 80

40（70）

29（64）

Neurosurgeons Gastroenterologists Gastrointestinal surgeons Orthopedic surgeons
26（55）

18（29）2（4）4（7）≥ 50 ‒ < 80

14（25）

9（20）

12（26）

23（38）

13（24）

14（26）

< 50

3（5）

7（16）

9（19）

20（33）

38（72）

36（67）

Unit：Number of medical institutions（%）

Arts and Sciences ◆ 69

rooms than X-ray ﬂuoroscopy rooms.

Construction of management system

2-4-4 Survey on the Wear of X-ray protective
glasses by clinical department

The X-ray protective glasses can reduce theeye lens exposure of physicians. Table 4 shows
the results of a survey of facilities where it waspossible to respond to the use of X-ray protective glasses worn by physicians of the respective departments. The use of X-ray protective
glasses was classiﬁed into three categories: Xray protective glasses are used in more than
80% of procedures (glasses are used in morethan 80% of treatments and examinations),
more than 50% and less than 80% of procedures(glasses are used in more than 50% and lessthan 80% of treatments and examinations), andless than 50% of procedures (glasses are used inless than 50% of treatments and examinations).
The percentages of physicians wearing X-ray
protective glasses by clinical department are as
follows: cardiologists (70%), diagnostic radiologists (64%), neurosurgeons (55%), gastroenterologists (29%), gastroenterological surgeons(4%), and orthopedic surgeons (7%). Compared to physicians who worked in angiography facilities, physicians who worked X-ray
ﬂuoroscopy rooms less wear the X-ray protective glasses.
2-4-5 Survey of reasons for physicians notwearing X-ray protective glasses by clinical department

The reasons for not wearing X-ray protective
glasses were that the glasses made it difﬁcult to
see the screen during the procedure (53%,39/74 facilities), they caused trouble due to thetwo layered glasses (35%, 26/74), fogging of
X-ray protective glasses (26%, 19/74), unnecessity for X-ray protective glasses (26%, 19/74),
the glasses were heavy (23%, 17/74), distorted
vision due to wearing the glasses (15%, 11/74),
the eye lens exposure dose is less than 20 mSv
per year (11%, 8/74), headache when using theglasses (5% 4/74), absence of glasses (4%,70 ◆ Journal of JART English edition 2023

n=74

24
32%
Consolidated
Not consolidated

50
68%

Fig.6 Status of committees established to manage
exposure at medical institutions

3/74), and using protective cloths and shielding plates (3%, 2/74).
2-5 【Radiation exposure management at
medical institutions】

To control patient and operator radiation exposure in medical institutions, each medical institution needs to take the initiative in exposure
control. For this reason, we surveyed the statusof the establishment of committees to control
patient and operator exposure in hospitals.
2-5-1 Survey of management status to control
patient and operator exposure

We surveyed if the participating institutions
have established the management system in
the hospital structure (in charge of dose management, manual availability, protection education, etc.) such as institutional committees tocontrol patient and operator exposure including the eye lens exposure. The survey results
showed that 68% of facilities (50/74) had suchmanagement arrangements, and 32% (24/74)
had no such arrangements (Fig.6).

3．Discussion
Reduction of exposure to the equivalentdose limit for the lens of the eye of medical
staff was mandated by the revision of the Regulations for the Prevention of Ionizing Radia-material
Research on eye lens exposure doses and exposure management for physicians involved in Interventional Radiology

tion Hazards in the Industrial Safety and HealthAct. To respond to this revision, we surveyed
the following issues about physicians: agendaof those who exceed the dose limit for lens
exposure, status of accurate measurement of
personal dosimetries, the use of X-ray protective equipment, the use and availability of Xray protective glasses, and management arrangements to control patient and operator
exposures in medical institutions.
3-1 【Eye lens exposure】

The results of this survey showed that the
proportion of physicians exceeding the dose
limit is higher than in a previous study 2). The
problems that exposure to the eye lens of physicians exceeds the dose limit will be discussed
for each clinical department. The highest percentage of physicians exposed to more than 20
mSv in a year and more than 100 mSv for a
5-year total for eye lenses is cardiologists.
When we compared the facilities where thephysicians were exposed to 100 mSv or morein 5 years with the facilities where the physicians were exposedz to 20 mSv or more in one
year, all (n=12) cardiologists, four of seven gastroenterologists, one of three diagnostic radiologists, and one of two gastroenterologicalsurgeons were in the same facilities. This suggests that they are constantly exposed to radiation at these same facilities.
There are 43 physicians of 17 facilities exceeding 20 mSv per year. Despite the fact thatthe more than 80% facilities used ceiling shielding plates for radiation protection during PCI,
EVT, and ABL procedures, the increase in thenumber of PCI and EVT procedures for chronic occlusions which require longer durations of
ﬂuoroscopy and more frequent imaging could
be the reasons for the higher eye lens exposure doses to physicians. The most effective
way to reduce the exposure to physicians is to
reduce ﬂuoroscopy and radiography doses
from angiography equipment. As shown in the“2020 Report on Reference Doses from Equip-

ment in FY2020” by the Japan Accreditation
Organization for Radiological Technologists
Specializing in Angiography and Interventions(as of April 11, 2021), there are variations indoses at medical facilities nationwide 5) .
For the future, the standardization of the ﬂuoroscopy and imaging doses of angiographyequipment would be expected in Japan. Physicians who were subject to the second most radiation exposures to eye lenses were gastroenterologists. In this present survey, the numberof physicians exposed to 20 mSv or more per
year was 14 at 10 facilities. The results of thesurvey showed that more than 80% of the facilities used X-ray protective cloths for radiation protection during ERCP. The reason forthe high eye lens exposure to physicians may
be because it is difﬁcult to perform puncture
procedures such as PTCD when using X-ray
protective cloths. The same approach to thisissue as described above can be applied to the
reduction of radiation exposure. The reductions of ﬂuoroscopy and radiography doses
from X-ray monitoring equipment can still contribute to the reduction of the exposure to theeye lenses of physicians.
Two reasons may explain why diagnostic radiologists and neurosurgeons, who perform
endovascular treatment in the same way as cardiologists, are less likely to exceed the eye lens
exposure dose limit than cardiologists. One
reason may be the difference in the number oftreatments. The other reason may be that the
distance between the surgeon and the X-ray
source tube changes depending on differencesin techniques. For example, in neurovasculartreatment, exposure to the surgeon is reduced
because the surgeon can stand at a greater distance from the X-ray tube than in PCI. The differences in the percentage exceeding the dose
limit of gastroenterologists, gastrointestinal surgeons, and orthopedic surgeons could be dueto the differences in the number of procedures
performed and the number of patients treated.

Arts and Sciences ◆ 71

3-2 【Management of personal dosimeters】

If exposure is not accurately measured, theevaluation of dose limits will be inaccurate.
This makes it impossible to evaluate the inﬂuence of radiation exposure on radiation workers. For this reason, exposure measurements
are very important to protect the health of physicians. This section discusses the status of
measurements of non-uniform exposures andthe use of personal dosimeters in different clinical department.
3-2-1 Measurement of uneven exposure

The measurement of non-uniform exposure
to physicians is clearly stated in the “2021 Revised Guidelines on Radiation Exposure in Cardiovascular Care (as of April 11, 2021) 6) by theJapanese Circulation Society. Descriptions for
non-uniform exposures control are in the recommended class I, Evidence Level A of theguidelines. Based on the results of the survey inthis study, for cardiologists, diagnostic radiologists, neurosurgeons, and gastroenterologists,
approximately 10% of facilities underestimatedthe eye lens exposure doses of physicians because the accurate non-uniform exposures were
not measured in those facilities. For gastroenterological surgeons and orthopedic surgeons,
37% and 29% of those facilities underestimatedthe eye lens exposure doses. The distribution ofindividual dosimeters among institutions may
differ because the cost of measurement equipment is borne by the hospitals. To reduce thisdifference among facilities, it is necessary forJapanese administrative agencies to provide
medical institutions with auditing guidance on
non-uniform exposures measurements and tooffer subsidies for radiation dosimetry.

sures, if the eye lens exposure dose is not accurately measured to determine whether it ishigh or low, the overall exposure may be signiﬁcantly underestimated. The results of thepresent study showed that the use of personal
dosimeters varied widely among physicians indifferent clinical departments. Among diagnostic radiologists who mainly perform endovascular treatment, 90% were able to accurately
measure exposure by using personal dosimeters. However, cardiologists and neurosurgeons reported less accurate measurements at
68% and 61%. Furthermore, the measurement
accuracies of gastroenterologists, orthopedic
surgeons, and gastroenterological surgeons
performing procedures in the X-ray ﬂuoroscopy room were only 53%, 45%, and 36%. These
results suggest that physicians except for diagnostic radiologists greatly underestimate theeye lens exposure doses. To improve on thissituation, information of the necessity of radiation dosimetry should be provided by professional societies, providing education and guidance on individual dosimetry at medical institutions. Further, government agencies mayneed to provide administrative guidance byconducting secret surveys without publicizing
the results. In addition, according to the report
by Kunugita Document 7 of the 2nd Study
Group on Lens Exposure, all physicians wore
personal dosimeters when the radiological
technologists “encouraged” physicians to wear
personal dosimeters 7). This suggests that efforts by radiological technologists in clinicalsettings can also lead to improvement of wearing dosimetry.
3-2-3 Incorrect position of head and neck dosimeters

3-2-2 Use of personal dosimeters

The most important aspect for the eye lens
exposure to physicians is to promote exposure
reduction measures so that the eye lens exposure dose does not exceed the dose limit.
When introducing exposure reduction mea-

72 ◆ Journal of JART English edition 2023

There were commonly reported errors in theplacement of the head and neck dosimeters by
gastroenterological surgeons, orthopedic surgeons, and gastroenterologists, who mainly
perform procedures in X-ray ﬂuoroscopy
room. It may be necessary to provide educa-material
Research on eye lens exposure doses and exposure management for physicians involved in Interventional Radiology

tion and guidance on personal dosimetry tosolve this problem.
3-2-4 Introduction of special eye lens dosimeters

Only 9% (7/74) of the facilities used eye lensdosimeters. Currently, many facilities measureeye lens exposure doses using two dosimeters
to measure non-uniform exposures. The dosevalues do not take into account the use of X-ray
protective glasses. Even if these dose values exceed 20 mSv per year, it will result in overestimated dose values if X-ray protective glasses
are used. Therefore, it would be more economical to limit the use of eye lens dosimeters tophysicians subject to 20 mSv or more annual
lens equivalent dose in the current non-uniform
exposure measurements. It would be realistic
way to minimize the management costs.
3-3 【X-ray protection】

It is widely known that the effective use of Xray protective equipment enables reductions in
the exposure to the eye lenses of physicians, butsuch equipment is not fully used. Here, we discuss various types of X-ray protective equipment.
3-3-1 Use of ceiling shielding plates and X-ray
protective cloths

The results showed that at facilities where
ceiling shielding plates are not commonly usedduring endovascular treatment, physicians areat the risk of exceeding the eye lens exposure
dose limits, although the number of such facilities is small. The reason for the low use ofceiling shielding plates and X-ray protective
cloths may be the presence of physicians withlow awareness of the importance of protection
against radiation exposure to the physicians.
To improve this situation, it is necessary to create a workplace culture that increases the number of physicians with a high awareness of radiation protection. Providing radiation protection education and guidance in clinical settings
as well as educational support from related

academic societies is important to create aworkplace culture of high protection awareness. Another factor for the low use of these
protective tools is the interference between theceiling shielding plates and the C-arm or vascular puncture route of angiography devices,which may interfere with the procedure, resulting in the absence of the shielding plates use.
Further studies are needed to increase theawareness of the need for protection among
physicians and to develop shielding plates thatwill not interfere with the procedures.
3-3-2 X-ray protective glasses

It is well known that X-ray protective glasses
can reduce the eye lens exposure to physicians. Problems based on this survey show thatthe availability of X-ray protective glasses anduse of the X-ray protective glasses differs greatly from angiography room to X-ray ﬂuoroscopy room.
Angiography rooms have more protective
glasses and a higher percentage of physicians
wearing X-ray protective glasses. Clearly, physicians who perform procedures in angiography rooms have a higher awareness of exposure protection. This may be because many
academic societies provide information on radiation protection during endovascular treatment. Many educational lectures on radiation
protection for physicians are held at related
conferences such as the Japanese Circulation
Society, the Japanese Association of Cardiovascular Intervention and Therapeutics, the Japan
Radiological Society, Japanese Society of Interventional Radiology, and the Japanese Society
for Neuroendovascular Therapy.
There were also many presentations on radiation protection by radiological technologists, offering opportunities to share information on radiation protection issues with physicians. From here on, it is desirable for the relevant academic societies involved in medical
treatment using X-ray ﬂuoroscopy rooms topublish guidelines on radiation exposure proArts and Sciences ◆ 73

cedures and issues. Many of the reasons for
not wearing X-ray protective glasses are related to the performance with X-ray protective
glasses, such as difﬁculties with seeing thescreen during procedures, inconvenience ofwearing overglasses, fogging of X-ray protective glasses, not feeling of the necessities for
X-ray protective glasses, heavy X-ray protective glasses, and distortion of vision due towearing X-ray protective glasses. These are inagreement with the opinion of physicians 8) reported in the Kunugita Document 2 of the 5th
Study Group on Lens Exposure, and the development of X-ray protective glasses that arelightweight, have good visibility, and do not
fog up is desirable.
3-4 【Radiation exposure management arrangements at medical institutions】

The Kunugita Document 4 of the 3rd Study
Group on Lens Exposure stated that administrative staff of hospitals need to establish occupational health management arrangements
where health managers and industrial physicians play central roles to promote occupational health measures. The document also reported that it is necessary to manage the workplaceenvironment, workers, and their health comprehensively with a proper understanding ofoccupational health activities through occupational health education 9). It is reported that radiation protection is effectively managed by an
occupational health and safety management
system with clear control methods to achieve
the goals. To introduce such occupational
health and safety management arrangements,
every medical institution needs to have a committee to control radiation exposure. In thissurvey, only 68% of the medical institutions
had established a committee to control radiation exposure. It is recommended that every
medical institution should introduce radiation
exposure control system for radiation workers
by utilizing such management arrangements.
In 2020, the Ministry of Health, Labour and74 ◆ Journal of JART English edition 2023

Welfare started a project to support the introduction of an occupational health and safety
management arrangement for radiation exposure as their commissioned project. We expect
the government to provide continual support
in the future.

4．Conclusions
The ﬁndings of this survey showed that there
are many physicians who do not accurately
measure the radiation exposures to their eyelens and there are also many facilities with inadequate protection equipment for physicians
to protect against radiation exposure. To improve the radiation exposure control for radiation workers, it is recommended that occupational health and safety management arrangements should be introduced and that hospitals
need to comprehensively manage radiation
exposure for radiation workers. Hospital administrators, medical radiation safety managers, industrial physicians, clinical physicians,
nurses, and radiological technologists must
work as a team to protect the health of radiation workers. In the hospitals that have difﬁculties in ensuring the proper use of personal dosimeters and X-ray shielding plates, it is important for radiological technologists to take theinitiative to improve the workplace environment.

5．Conﬂicts of interest
There are no conﬂicts of interest to be disclosed in relation to this study.

Acknowledgements
We would like to express our sincere gratitude to the members of the Japanese Society ofRadiation Public Safety and the radiological
technologists of each Red Cross hospital who
cooperated with the questionnaire survey ofthis research during their busy schedules.

material
Research on eye lens exposure doses and exposure management for physicians involved in Interventional Radiology

Reference literature
1） The 2nd Study Group on the Revision of the Exposure
Limits for the Lens of the Eye Submitted Material
3.（Accessed 2020.8.1）．
h t t p s : / / w w w. m h l w. g o . j p / c o n t e n t / 1 1 2 0 1 0 0 0 /000477102.pdf
2） The 2nd Study Group on the Revision of Exposure
Limits for the Lens of the Eye Submitted Material
5.（Accessed 2020.8.1）
h t t p s : / / w w w. m h l w. g o . j p / c o n t e n t / 1 1 2 0 1 0 0 0 /000477104.pdf
3） The 6th Study Group on the Revision of Exposure
Limits for the Lens of the Eye Submitted material
4.（Accessed 2020.8.1）
h t t p s : / / w w w. m h l w. g o . j p / c o n t e n t / 1 1 2 0 1 0 0 0 /000534350.pdf
4） Yasuhiro Meguro, Hiroshi Watanabe, et al.: Necessityof a revised ministerial ordinance guide for medical
institutions and local government agencies. Nippon
Journal of Japanese Games, vol.67, no.817, 2020.
http://www.jart.jp/activity/ib0rgt0000006kexatt/2020-11_paper2.pdf
5） Japan Angiography and Intervention RadiologicalTechnologist Accreditation Organization: [Source]

Report on the reference dose of the device in FY2020.
（Accessed 2021.4.11）

http://ivr-rt.kenkyuukai.jp/special/?id=18190
6） Japan Cardiovascular Society: 2021 Revised
Guidelines for Radiation Exposure in Cardiovascular
Practice.（Accessed 2021.4.11）
https://www.j-circ.or.jp/cms/wp-content/uploads/
2021/03/JCS2021_Kozuma.pdf
7） The 2nd Study Group on Revision of Exposure
Limits for the Lens of the Eye Submitted Material
7.（Accessed 2020.8.1）
h t t p s : / / w w w. m h l w. g o . j p / c o n t e n t / 1 1 2 0 1 0 0 0 /000477751.pdf
8） The 5th Study Group on the Revision of Exposure
Limits for the Lens of the Eye Submitted Material
2.（Accessed 2020.8.1）
h t t p s : / / w w w. m h l w. g o . j p / c o n t e n t / 1 1 2 0 1 0 0 0 /000519683.pdf
9） The 3rd Study Group on the Revision of Exposure
Limits for the Lens of the Eye Submitted material
4.（Accessed 2020.8.1）
h t t p s : / / w w w. m h l w. g o . j p / c o n t e n t / 1 1 2 0 1 0 0 0 /000490657.pdf

Arts and Sciences ◆ 75

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
October 3, 2020
July 9, 2022
December 3, 2022
Objective

Article 1. These regulations are based on the operations defined in Article 4 of the articles on theincorporation of the Japan Association of Radiological Technologists (hereafter “theAssociation”). They stipulate the criteria for submissions to the Journal and informationalmagazines published by the Association (hereafter “the Journal, etc.”).
Eligibility

Article 2.
2-1. Only members of this association are allowed to submit articles to the associationʼs journal, etc.
2-2. However, the following requirements must be met in order to submit articles:(1) Students of radiologic technology schools who have a member of this association as a coauthor.
(2) Individuals with a foreign nationality who hold a radiologic technologist license.
(3) Non-members other than the above may submit articles by paying half of the association
membership fee per article as a submission fee.
2-3. The submission fee stated in the preceding paragraph 3 will not be refunded regardless ofwhether the article is accepted or not.
2-4. Co-authors do not need to pay the submission fee.
Copyright

Article 3. The copyright of the published manuscript is based on rules regarding the management of theworks of the Society.
Obligations

Article 4.
4-1. The topic of submitted manuscripts must belong to a relevant domain to technologies forprevention, diagnosis, and treatment related to radiation therapy, and manuscripts must be
unpublished.
4-2. Submitted papers, whether for fundamental or applied research, must sufficiently consider
bioethics, and authors must bear the ultimate responsibility for their content.
4-3. Fabrication, forgery, plagiarism, violation of the law, and other forms of wrongdoing are notallowed in submissions.
4-4. If the author has already reported similar content to that of the published manuscript or
submitted it to another journal, the author is required to explain the difference from themanuscript in a separate document.
4-5. The author must disclose all information regarding conflicts of interest.
4-6. The author shall be held accountable for any misconduct regarding the content of the
publication, and the Society shall not be involved at all.
Submissions

Article 5. The types of accepted submissions are categorized as follows:(1) Original articles
Highly original research papers with clear objectives and conclusions.
(2) Review articles
Articles systematically summarizing a specific research domain from a particular perspective.
(3) Rapid communications
Reports of original research that must be published rapidly.
(4) Reports
Surveys of significance to the study of radiological technology or reports of interesting and76 ◆ Journal of JART English edition 2023

important cases.
(5) Notes
Articles on the development or evaluation of new equipment, techniques, products, etc.
(6) Technical material
Compilations of survey data or technical aspects, or anything that can serve as a reference forresearch and technology.
(7) Overview articles
A compilation of technologies, principles, or basic elements with reference to the literature.
However, what was explained in the development and use of equipment and software constitutes
a technical explanation.
(8) Miscellaneous
Other items approved by the editorial committee for publication, such as lecture transcripts, courses
published as journal articles, and newspaper/magazine articles that were not published in Issues 1–7.
How to submit

Article 6.
6-1. Use the online posting system.
6-2. The author shall save the duplicate data of the submitted manuscript until the publication decision.
Formatting

Article 7. The explanation of the manuscript shall be provided according to the submission procedure
specified separately.
Reception of submissions

Article 8. The reception date shall be the date on which the editorial board has determined to comply
with this regulation.
Review

Article 9.
9-1. Received manuscripts will be reviewed carefully and impartially by peer-reviewers selected by
the editorial committee.
9-2. Peer reviews are limited to two times. However, in the case of Article 5, items 7 and 8, in
principle, peer review is not performed.
9-3. The acceptance or rejection of the manuscript will be decided by the editorial committee inconsideration of the opinions of the reviewers, and the date will be the final acceptance date.
Corrections

Article 10.
10-1. In principle, the author must proofread the manuscript up to twice and return it by thedesignated date. If the deadline is breached, the school will be completed with the proofreadingof the editorial board.
10-2. The correction of words and plates that were not included in the manuscript is not allowed.
Printing

Article 11.
11-1. 20 copies of the papers published in the Journal, etc., will be presented to their authors as anoffprint.
11-2. The authors must bear the expenses of any additional offprints. If additional offprints are
required, they must be requested by the time corrections are submitted.
Revision or repeal of regulations

Article 12.
12-1.
12-2.
12-3.
12-4.
12-5.
12-6.

This regulation will come into effect on April 1, 2012.
This regulation will come into effect on April 1, 2016.
This regulation will come into effect on April 20, 2019.
This regulation will come into effect on October 3, 2020.
This regulation will come into effect on July 9, 2022.
This regulation will come into effect on December 3, 2022.

Regulations and Requirements for Submissions ◆ 77

Requirements for Submissions to the
Journal of the Japan Association of Radiological Technologists
Revised: February 20, 2016
April 20, 2019
October 3, 2020

The formatting requirements for manuscripts specified in Article 7 of the submission regulations of the
Journal of the Japan Association of Radiological Technologists are as follows:
1. How to write original articles, reviews, breaking news, reports, notes, materials, and explanations.
1) Title and abstract
Enter the following items in the online posting system.
①Enter the authorʼs name, facility name, affiliation, occupation, and contact information, and selectthe specialized field.
②Select the type of post.
③Enter the title and co-author information in Japanese and English. Co-authors are limited to membersof the Society. However, this does not apply if the co-author is not a radiological technologist.
④Summarize the abstract in Japanese and English within 300 characters (words).
⑤Enter the keywords in English. Keywords should be in noun forms and should be limited to five.
2) Text and figures/tables
For the text and figures/tables, create and post both a separate file and a file containing figures andtables within the text.
①The manuscript should be written in Japanese or English.
Create the manuscript using Word with a paper size set to the A4 size. The type and size of the
fonts should be 12 points for both Japanese and English fonts, Mincho font, and Times. The line
spacing should be 18 points. Leave a margin of 2 cm or more on the top, bottom, left, and right.
②The specified number of pages and excess page costs of the manuscript are as shown in thefollowing table.
Type of submission
Original articles
Review articles
Rapid communications
Reports
Notes
Technical material
Overview articles
Technical overview articles
Miscellaneous

Number of pages (as published)
8
8
3
3
8
8
8
4–6
2 (strictly enforced)

Fee for additional pages¥10,000 per pageNone

③As a general rule, academic terms should conform to Cabinet Notification No. 2 and JIS.
④The unit of quantity is the International System of Units (SI).
⑤Indicate the insertion position of the figure/table in red in the text created as a separate file fromthe figure/table.

⑥The figures and tables created as separate files from the main text are of higher resolution and canbe subjected to secondary processing in production.

⑦For academic treatises, write the title and characters in the table in English.
⑧When reprinting figures/tables, specify the source and obtain permission.
⑨Attach the explanation of the figures and tables in Japanese in a separate file.

3) References
References should be listed in the order in which they appear, with the numbers in parentheses atthe end of the referenced text.
The notation format is as follows.
①For magazines
Author names: Title (article title) Magazine name (abbreviation), volume, first-last page, year of
publication.
②For a book
Author names: Book title, First-last page, publisher, year of publication.
③If there are two or more authors, enter only the first author and enter “other” and “et al.”

78 ◆ Journal of JART English edition 2023

4) Trademark name
If a trademark name is required, write the trademark name in both parentheses after the common
name and add Ⓡ.
2. Submission of copyright transfer agreement(1) The first author and co-authors must agree with the contents of the copyright transfer agreement
stipulated in the copyright management regulations.
(2) The copyright transfer agreement shall be stipulated by the rules regarding copyright management,
and the format specified on the Societyʼs website should be used.
(3) The copyright transfer agreement must be signed by the first author and co-authors, and provided
when the manuscript is submitted.
3. About secondary publication(1) Obtain approval from the editorial departments of both the first and second journals.
(2) The period until the secondary publication should be decided through discussions between theeditorial departments of both parties and the author.
(3) Secondary publications of treatises are intended for different types of readerships.
(4) The secondary publication of a treatise should faithfully reflect the content of the first treatise.
(5) Specify the source of the original treatise.
(6) Specify in the title that it is a secondary publication.
4. About technical commentary requested by the editorial board.
The composition of the text is as follows (1) to (9).
(1) Abstract (100-150 words in Japanese and English)(2) Keywords (3 words)(3) Introduction:(4) Purpose of explanation (overview)(5) Main paper(6) Comparison and consideration with previous research (development technology)(7) Clinical usefulness(8) Conclusion(9) References

Regulations and Requirements for Submissions ◆ 79

Journal of JART–English edition 2023–

June 16, 2023
Issuer: Ueda Katsuhiko
Publisher: The Japan Association of Radiological Technologists
22F Mita Kokusai Building. 1-4-28,
Mita, Minato-ku, Tokyo. 108-0073
TEL: +81-3-4226-2211 FAX: +81-50-3153-1519
https://www.jart.jp
・Published by The Japan Association of Radiological TechnologistsⒸ2023, Printed in Japan.

The Japan Association of Radiological Technologists
https://www.jart.jp