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www.phwr.org Vol 16, No 31, 2023
108 2
서 론
질병의진단과치료를 위해서 의료피폭인환자선량은한
도를두지않으나, “합리적으로 달성가능한한 낮게(
as
low
as
reasonably
achievable
,
ALARA
)”의원칙을세우고 환자에
게방사선을조사하고있다.
ALARA
를달성하기위해정당화
(
justification
)와최적화(
optimization
)의절차를거치는 것이
일반적이다[1].정당화는주로의사에의해서이루어지며,환
자의질병진단및 치료를위하여방사선검사가 필수불가결
하다는판단을내리는 과정이다[1]. 환자선량은조사되는방
사선의검사조건(관전압,관전류,조사시간등)에의해결정된
다.따라서,정당화절차후촬영종류별로검사조건의최적화
과정을거쳐야하는데 이때가장널리 활용되는것이진단참
고수준(
diagnostic
reference
level
,
DRL
)이다[2].
DRL
은국제방사선방호위원회(
International
Commission
on
Radiological
Protection
)및국제원자력기구(
Inter
national
Atomic
Energy
Agency
)가의료피폭의 최적화를달성하기 위
한도구로서권장하고있는개념이다[2].이미세계의많은국
2022년 일반촬영 및 유방촬영의 국가 진단참고수준 마련
윤용수1, 박혜민2, 원종훈3, 송승기3, 길종원3, 이병영3*
1동서대학교 방사선학과, 2마산대학교 방사선과, 3질병관리청 의료안전예방국 의료방사선과
초 록
의료방사선에서 환자선량은 한도를 두지 않으나, 최적화를 달성해야 하며 이를 위해 사용되는 도구로 진단참고수준(
diagnostic
reference
level
,
DRL
)이 있다.
DRL
은 국가, 지역 또는 기관 단위로 설정할 수 있으며 주기적으로 개정하는 것이 권고된다. 우리나라는
질병관리청을 통해 국가 차원의
DRL
이 제공되고 있으며, 본 연구는 2022년에 전국 조사를 통해 일반촬영 및 유방촬영의 새로운 국가
DRL
을 마련하고자 수행되었다. 본 연구에서는
DRL
마련을 위해 진단용 방사선 발생장치 검사기관에서 각 촬영종류별 검사조건 및 그
에 대한 선량측정 데이터를 수집하고 본 연구팀에서 데이터 정리 및 분석을 실시하여 국가
DRL
을 도출하는 방식으로 연구 방법을 설계
하였다. 질병관리청에 등록 된 검사기관 중 4개 검사기관에서 진단용 방사선 발생장치 검사를 실시할 때 해당 장치에 대해
DRL
도출 을
위한 데이터를 수집하였다. 그 결과 이전 연구들 보다 많은 수의 의료기관 및 장치에 대한 데이터를 확보할 수 있었으며, 특히 병·의원의
데이터가 많이 포함되어 실질적인 현실 반영이 이루어진
DRL
을 도출할 수 있었다. 본 연구 이후 도래되는
DRL
전국 조사 시에 더욱 원
활하고 다양한 조사가 이뤄질 수 있을 것이라 기대된다.
주요 검색어: 일반촬영; 유방촬영; 진단참고수준; 환자선량; 최적화
eISSN 2586-0860
https://doi.org/10.56786/PHWR.2023.16.31.2
연구 논문
Copyright Ⓒ Korea Disease Control and Prevention Agency
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://
creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any
medium, provided the original work is properly cited.
Received June 7, 2023 Revised June 21, 2023 Accepted July 3, 2023
*Corresponding author: 이병영, Tel: +82-43-719-7511, E-mail: lkd@korea.kr
www.phwr.org Vol 16, No 31, 2023 1083
가와지역에서설문조사및실제선량측정조사를통해일정
주기를가지고보고되고있다.
각촬영 종류별
DRL
은조사 결과에서3사분위값(75%)의
선량으로표시하는것이 일반적이다.
DRL
은개인의방사선
방호를위해초과해서는안되는선량한도나선원중심평가를
통해개인의 피폭을예방적차원으로제한하는선량제약치와
같이제한의개념이아니다.
DRL
은진단및치료를위해의료
피폭에한도를설정할 수없는대신 최적화를달성하기위해
적용되는“참고치”라는것을반드시유념해야한다[2].
DRL
을초과하는선량으로 촬영하고있는시설은 선량의
최적화를검토하는것이요구된다.한편,
DRL
보다너무낮은
선량으로검사가실시되고있는시설은진단에유용한정보를
제공할수있는화질이담보되고있는지확인할필요가있다.
방사선의학에관련된의료진 및관련연구자들에게
DRL
의개념및활용방법, 국민보건의향상을위한방사선진료의
정당화와그사용 선량의최적화정보를 주기적으로 제공할
필요가있다.
이에따라세계많은국가에서자국의
DRL
을설정하여국
가차원의환자선량 최적화 방안을마련하고있다. 우리나라
의경우2007년에 성인흉부및 유방촬영에대한
DRL
설정
을시작으로점차여러촬영종류로확대되어국가
DRL
이마
련되었다[3,4].이후,2017년과 2018년 두해에걸쳐 소아
및성인의일반촬영및유방촬영의국가
DRL
마련을위한연
구가수행되었으며,2019년에질병관리청을통해진단참고수
준가이드라인이발간되었다. 이때일반촬영의종류는 두부,
흉부,복부,척추,골반,사지부위를포함한다[3,4].
본연구는일반촬영및유방촬영의새로운국가
DRL
마련
을목표로2022년에 국내의료기관의환자선량데이터를조
사및정리하였으며 이를토대로의료기관에서 검사조건 및
환자선량의최적화에참고할수있는
DRL
을제시하였다.
특히,본연구에서는 이전에수행된
DRL
수립연구에서
시도되지않은방법을통해
DRL
을조사하였다.보다많은데
이터수집을통해도출된
DRL
의신뢰성을높이기위해,기존
의
DRL
수립을위한모든과정을단일연구팀에서수행한것
과달리본연구에서는
DRL
조사방법의수립및데이터분석
팀과실제현장측정팀으로분리하였다. 이에본원고를통해
새롭게시도된국가
DRL
조사방법을소개하고자한다.
방 법
1. 진단용 방사선 발생장치 검사절차와 DRL 조사 과정
의료법제37조에따른보건복지부령인[진단용방사선발
생장치의안전관리에관한 규칙]은 의료기관에서설치및 운
영하는진단용방사선 발생장치(이하‘진방장치’)를 안전하게
관리함으로써환자및방사선관계종사자가방사선으로인하
여위해를입는 것을방지하고진료의 적정을도모하기위하
여필요한사항을규정하는것을목적으로한다[5].
해당규칙에따르면,의료기관개설자또는관리자는진방
장치를사용하기전, 그리고매3년마다 검사기관을통해장
핵심요약
① 이전에 알려진 내용은?
“
As
low
as
reasonably
achievable
”원칙에따라 의료방사
선에서환자선량은최적화되어야한다.이를위해국가차원
에서진단참고수준(
diagnostic
reference
level
,
DRL
)을설정
하고있다.국제적으로
DRL
은주기적으로개정될것이권고
된다.
② 새로이 알게 된 내용은?
본연구에서는기존 연구와달리
DRL
조사방법을 개선하
여장치검사기관과 함께일반촬영장치및 유방촬영장치
총517대의많은 표본데이터를수집했다. 이를통해국가
DRL
을도출하기위한통계분석의신뢰도를높였다.
③ 시사점은?
의료기관에서적극적으로환자선량 최적화를달성할수 있
도록국가
DRL
을통한지속적인홍보및교육이필요하다.
www.phwr.org Vol 16, No 31, 2023
108 4
치검사를 받아야한다[5,6].이때검사를수행하는검사기관
은질병관리청에등록된 기관으로현재표 1과 같이총5개
기관이등록되어운영중에있다.이중,육군제2879부대를
제외한네개 기관에서전국에지부를 두고진방장치를사용
하는모든의료기관을대상으로검사를수행하고있다[7,8].
진방장치의검사를 받고자하는 의료기관개설자 또는관
리자는검사신청서를검사기관의장에게제출한다.신청을받
은검사기관은검사를시행한후검사성적서를신청인에게발
급하여야하며,검사 또는측정한날부터 1개월이내에검사
결과를질병관리청장에게제출하여야한다[5,8].
본정책연구는국가
DRL
의정확성과데이터수집효율성
을높이기위해 검사기관에서진방장치검사를 수행할때더
불어선량측정을수행하여
DRL
조사가이뤄지도록설계되었
다.자체검사를실시하는기관을제외한 나머지네개검사기
관에서본연구에함께참여하여
DRL
의현장조사를수행하였
다.
DRL
조사과정은그림1과같다.의료기관개설자또는관
리자가진방장치검사를 신청하면,검사기관에서
DRL
연구
협조를요청하고 이를의료기관에서수락하면진방장치검사
후
DRL
조사를추가로 실시하였다.이후검사기관에서는본
연구팀에수집된데이터를전달하고,본연구팀은해당데이터
를바탕으로 일반촬영의촬영종류별및유방촬영에대한새로
운국가
DRL
을도출하였다.또한,조사에참여한 의료기관에
피드백이제공될수있도록도출된
DRL
과각의료기관의측정
값의비교를담은개별의료기관피드백자료를생성하였다.
2. DRL 데이터 수집을 위한 조사지 개발
실제조사를수행하는 검사기관과의논의를통해새로운
국가
DRL
도출을위한데이터수집조사지를 개발하였다.조
사지는크게의료기관 정보,방사선발생장치정보, 영상처리
장치정보,그리고검사항목별촬영정보의4가지부분으로구
성된다(그림2).
의료기관정보의경우 ①지역, ②의료기관종,③의료기
관자체선량관리시스템 유무,④일반촬영장치측정대수,
⑤유방촬영장치 측정대수,그리고⑥영상처리장치측정대
수를기입하도록 하였다.지역은서울,인천,경기도,강원도,
충청도,전라도,경상도,그리고제주도로구분되며,의료기관
종은상급종합병원,종합병원, 그리고병‧의원으로구분된
다.의료기관자체선량관리시스템유무의경우유또는무로
구분되며,영상처리장치의경우
Film
/
Screen
,
computed
ra-
diography
(
CR
)
system
,그리고
digital
radiography
(
DR
)
sys-
tem
으로구분된다.
장치정보는일반촬영장치의경우 ①제조사,② 모델명,
③제조일자,④ 고전압발생장치 형식,⑤고유여과, ⑥최근
장치검사결과,그리고⑦ 면적선량(
dose
area
product
,
DAP
)
부착유무가기입되어야한다. 여기서고전압발생장치 형식은
단상,삼상그리고인버터로구분되며, 고유여과는
mm
단위
로알루미늄(
aluminum
,
Al
)또는구리(
copper
,
Cu
)등조사
대상장치의고유여과물질을기입한다. 최근장치검사결과
는합격또는불합격으로기입하여, 불합격일경우불합격항
목을기입하도록하였다.이는검사항목 중선량의재현성항
목이적합이라는것을 토대로본연구에서 수집된 데이터의
그림 1. 본 연구에서 설계한 국가
diagnostic
reference
level
(
DRL
) 조사 흐름도
표 1. 진단용 방사선 발생장치 검사기관 현황(2022.11.17. 기준)
등록번호 기관명 소재지
검사22-1호 육군제2879부대
(자체검사)
-
검사22-2호 (재)한 국의료기기기술 원 서울특별시중랑구
검사22-3호 (재)한국의료기기평가 원 경기도성남시분당구
검사20-1호 (재)한 국의료기기검사 원
부설방사선안전검사원
경기도성남시분당구
검사20-2호 (주)중앙기술검사원 대구광역시북구
www.phwr.org Vol 16, No 31, 2023 1085
신뢰성을확보하고자함이다[5,6].
DAP
부착유무는유 또는
무로구분되며,
DAP
가부착되어있으면
DAP
에서측정된값
도같이기입하며,
DAP
가부착되어있지않으면서
DAP
값이
콘솔에표시되는경우도마찬가지로표기된값을같이기입하
여해당값이 실제측정값인지제조사에서 계산에의해도출
된값을제공하는것인지를구분하는데사용되는항목이다.
유방촬영장치의경우①제조사,② 모델명,③ 제조일자,
④고전압발생장치형식, ⑤타겟(
target
),⑥고유여과, ⑦최
근장치검사결과,그리고 ⑧선량계부착여부가 기입되어야
한다.고전압발생장치 형식은단상,삼상그리고인버터로구
분되며,타겟은몰리브덴(
molybdenum
,
Mo
),로듐(
rhodium
,
Rh
),텅스텐(
tungsten
,
W
),그리고기타로구분된다.고유여과
는
mm
단위로
Al
,베릴륨(
beryllium
),
W
,
Mo
,
Rh
,
Cu
,그리
고기타로구분된다.
영상처리장치의정보는일반촬영과유방촬영이동일하며,
①형식,②제조사,③모델명,그리고④선량정보표시가기
입되어야한다.형식은
Film
/
Screen
,
CR
system
,그리고
DR
system
으로구분된다.선량정보 표시의경우촬영 시콘솔에
A
B
C
D
그림 2.
Diagnostic
reference
level
측정을 위해 개발된 조사지
(
A
)의료기관정보기입항목.(
B
)일반촬영및유방촬영장치정보 기입항목.(
C
)영상처리장치정보기입항목.(
D
)일반촬영및유방촬영의검사항목별
촬영조건과 선량정보기입항목.
CR
=
computed
radiography
;
DR
=
digital
radiography
;
DAP
=
dose
area
product
;
DRL
=
diagnostic
reference
level
;
ESD
=
entrance
surface
dose
;
AP
=
anterior
-
posterior
;
PA
=
posterior
-
anterior
;
LAT
=
lateral
;
SID
=
source
to
image
receptor
distance
;
AEC
=
automatic
exposure
control
system
;
Mo
=
molybdenum
;
Rh
=
rhodium
;
Al
=
aluminum
;
Cu
=
copper
;
AGD
=
average
glandular
dose
;
HVL
=
half
value
layer
;
mAs
,
milli
ampere
second
.
www.phwr.org Vol 16, No 31, 2023
108 6
표시되는값으로일반촬영의 경우없음,
DAP
,입사표면선량
(
entrance
surface
dose
,
ESD
),그리고노출지수(
exposure
in-
dex
,
EI
)로구분되며,유방촬영의 경우없음,
ESD
,입사표면
노출(
entrance
surface
exposure
,
ESE
),평균유선선량(
average
glandular
dose
,
AGD
),그리고
EI
로구분된다.표기되는선량
정보값이여러가지일경우복수로기입한다.
검사항목별촬영정보는 일반촬영및유방촬영모두①관
전압,②관전류,③조사시간, ④
milli
ampere
second
,⑤조
사야(가로,세로 각각),⑥
source
to
image
receptor
distance
,
⑦그리드비율, ⑧자동노출제어시스템(
automatic
exposure
control
system
,
AEC
)적용유무,⑨ 부가필터, 그리고⑩선
량정보가기입되어야한다. ①–⑨의 항목은각검사항목별로
실제해당의료기관에서 사용되고있는내용을 작성하는 것
이며,해당조건으로 조사했을 때검사기관의선량계로 측정
되는값을선량정보에 기입한다.만일선량정보가 표기되는
장치일경우측정값과 동시에표기되는값(일반촬영:
DAP
,
ESD
,또는
EI
/유방촬영:
ESD
,
ESE
,
AGD
,또는
EI
)또한작
성한다.일반촬영의경우
AEC
가적용되는검사항목에대해서
는검사기관이 보유하고있는 물팬텀(20×20×20
cm
3
)을사
용하여측정을 진행하며,유방촬영의경우
American
College
of
Radiology
(
ACR
)팬텀을사용하여측정을진행한다. 유방
촬영에서
AGD
측정값은측정된
ESD
값에조사시간,반가층
(
half
value
layer
)등을고려하여계산에의해도출한다.
일반촬영은소아(5세및 10세)와성인으로구분하여 조
사하였다.소아의경우
skull
anterior
-
posterior
(
AP
),
chest
posterior
-
anterior
(
PA
),
chest
lateral
(
LAT
)등13개 검사종
류에대해조사하였으며,성인의경우소아검사항목에
cervi-
cal
spine
AP
,
LAT
,
thoracic
spine
AP
,
LAT
,
lumbar
spine
(
L
-
Spine
)
AP
,
LAT
의6개항목을더하여총19개검사종류에
대해조사하였다.
3. DRL 데이터 수집 및 분석
검사기관에서
DRL
연구협조를 수락한의료기관에방문
하여
DRL
조사지를바탕으로해당의료기관의정보, 장치정
보및각촬영종류별검사조건과그에따른측정선량값을기
입한다.본연구팀에서는현장의애로사항 확인및일관성있
는데이터확보를 위해주기적인 현장방문을그림 3과같이
진행하였다.
검사기관을통해수집된
DRL
데이터의값은이상치(
outli-
er
)제외등과같은데이터보정이이루어지지않은원시(
raw
)
데이터로정확한
DRL
통계결과를얻기위해통계분석전문
가와데이터통계및비교분석을 진행하였다.각촬영종류별
로측정된선량값 분포에서최소,최대, 평균,중간,3사분위
값을도출하였으며,이중 3사분위값을해당 촬영종류에대
한
DRL
로선정하였다[2].더하여 조사지에 기입된의료기관
에대한 정보,장치에대한정보및촬영조건에대한정보등
에따른선량비교를실시하였다.
결 과
일반촬영및유방촬영의국가
DRL
을마련하기위해수행
된본조사연구에서는총454개의료기관으로부터일반촬영
장치382대, 유방촬영장치135대에 대한데이터가 수집되었
다.조사된의료기관의 종별 분포는일반촬영장치의경우 상
급종합병원이7%,종합병원이17%,병‧의원이76%,유방촬
영장치의경우상급종합병원이 10%,종합병원이26%,병‧
의원이64%이다.
수집된데이터를분석한 결과,표2및 표3과같이 일
반촬영및유방촬영의 각검사종류별국가
DRL
이도출되
었다.일반촬영의소아 5세에서
Ankle
AP
검사의
ESD
가
0.16
mGy
로가장낮은 값을나타냈으며,
abdomen
AP
검
사가1.40
mGy
로가장높은 값을나타냈다.소아 10세의
경우
hand
PA
검사의
ESD
가0.18
mGy
로가장낮은 값을,
www.phwr.org Vol 16, No 31, 2023 1087
abdomen
AP
가2.28
mGy
로가장 높은값을나타냈다.그리
고성인의경우
hand
PA
검사의
ESD
가0.27
mGy
로가장낮
은값을,
L
-
Spine
LAT
이8.49
mGy
로가장높은값을나타냈
다.유방촬영의 경우
ESD
8.40
mGy
,
AGD
1.56
mGy
의결
과가도출되었다.
조사된의료기관종별로선량분포를비교한결과,일반촬
영의경우소아와성인모두에서 모든촬영종류에대해병‧
의원이가장높은 값을나타냈으며,종합병원, 상급종합병원
순으로낮아지는경향을나타냈다.유방촬영역시일반촬영과
동일한경향을나타냈다.
논 의
본정책연구에서는일반촬영과 유방촬영에대한환자의
연령에따른촬영종류별
DRL
마련을위하여, 의료기관에서
사용하고있는환자선량데이터를수집하고이를토대로의료
기관에서검사조건및 환자선량의최적화에활용할 수 있는
국가
DRL
을제시함으로써 의료방사선안전관리에관한정책
A
B
그림 3. 검사기관의
diagnostic
re
-
ference
level
(
DRL
) 조사 모습
(
A
)일반촬영장치의
DRL
조사모습.(
B
)
유방촬 영장치의
DRL
조사모습
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108 8
에반영될수있는데이터구축을목적으로하였다.
기존질병관리청(구식약처 및질병관리본부)에서주기적
으로갱신해오던
DRL
수립연구와 이번연구의가장 큰 차
이점은
DRL
조사방법에 있다고할수 있다. 기존의연구는
DRL
의제시항목(검사프로토콜)설정및대상장치및지역,
병원종별비율 설정과선량측정을 단일연구팀에서실시하
였으나,본연구에서는
DRL
마련을위한조사항목검토부터
측정방법수립은본연구팀에서시행하고실제의료기관에서
의측정은진방장치 검사기관이본연구팀의 현장지도 하에
수행하였으며,측정이완료된후데이터를 제공받아본연구
팀에서최종적으로통계분석하여국가
DRL
을도출하였다.
기존의연구방법과 비교하여 본연구의가장 큰특징으
로는,측정 건수를큰폭으로증가시킴으로써(전국조사의료
기관수:454기관,측정한일반촬영장치및유방촬영장치대
수:517대)보다 많은 표본의데이터를획득하였고, 이를통
해통계분석의신뢰도를향상시킬수있었다는점을들수있
다.또한, 측정에사용된진방장치는규정에따른검사기준을
충족하였으므로장치의정도관리수준에따른측정결과의부
정확성을줄였다고할 수있다.그러나 장치검사 의뢰,접수
및수행절차상
DRL
조사를위해사전에의료기관의 협조를
획득하는데에는어려움이 있으며,
DRL
에대한사전 지식이
전무한경우도다반사였다.그럼에도불구하고그동안종합병
원이상급으로편중되어 있던환자선량최적화를 위한 노력
및
DRL
에대한정보들이본연구수행을통해전국의다양한
종별의의료기관에널리전파될수 있을것이라생각된다.따
라서본연구이후도래되는
DRL
전국조사시에더욱원활하
고다양한조사가이뤄질수있을것이라기대된다.
국내에서2017년및2018년에조사된국가
DRL
과본연
구로도출된
DRL
을비교해보았을때,전반적으로
DRL
이상
승하는경향을 나타냈다[3,4].이는측정방법의차이에서기
인한것으로보이며,본연구는 측정건수를대폭향상시킴으
로써비교적더높은대표성을가진다는점에의의가있다.본
표 2. 일반촬영의 연령 및 검사종류별
DRL
검사종류 ESD (mGy) DAP (mGy‧cm2)
5세
Skull
AP
1.01 515.30
Chest
PA
0.32 405.82
Chest
LAT
0.75 912.41
Abdomen
AP
1.40 1,552 .78
Pelvis
AP
1.17 1, 30 5.59
Shoulder
AP
0.5 9 36 5.58
Humerus
AP
0.39 526.63
Elbow
AP
0.19 73.30
Hand
PA
0.20 47.4 8
Hip
Joint
AP
1.07 1,163.78
Femur
AP
0.60 733.31
Knee
AP
0.26 162.67
Ankle
AP
0.16 63.40
10세
Skull
AP
1.59 803.52
Chest
PA
0.47 613.36
Chest
LAT
1.06 1,231.84
Abdomen
AP
2.28 2,418.4 3
Pelvis
AP
2.08 2 ,2 08.59
Shoulder
AP
0.83 485.89
Humerus
AP
0.66 881.18
Elbow
AP
0.27 103.67
Hand
PA
0.18 69.79
Hip
Joint
AP
1.9 0 1,9 61.77
Femur
AP
0.9 7 1,152 .94
Knee
AP
0.42 256.08
Ankle
AP
0.26 102.62
성인
Skull
AP
2.55 1,226.26
Chest
PA
0.68 769.23
Chest
LAT
1.55 1,592.29
Abdomen
AP
3.80 3,645.52
Pelvis
AP
3.70 3, 337.3 4
C
-
Spine
AP
1.36 588.4 4
C
-
Spine
LAT
1.22 527.47
T
-
Spine
AP
3.70 3,5 51.99
T
-
Spine
LAT
5.86 5,574.46
L
-
Spine
AP
4.83 4,653.46
L
-
Spine
LAT
8.49 8 ,21 3.78
Shoulder
AP
1.55 636.23
Humerus
AP
0.9 3 912 .15
Elbow
AP
0.42 134 .99
Hand
PA
0.27 91.61
Hip
Joint
AP
3.22 2,079.74
Femur
AP
1.88 1,489.5 5
Knee
AP
0.7 3 314.57
Ankle
AP
0.5 0 147. 21
DRL
=
diagnostic
reference
level
;
ESD
=
entrance
surface
dose
;
DAP
=
dose
area
product
;
AP
=
anterior
-
posterior
;
PA
=
posterior
-
anterior
;
LAT
=
lateral
;
C
-
Spine
=
cervical
spine
;
L
-
Spine
=
lumbar
spine
;
T
-
Spine
=
thoracic
spine
.
www.phwr.org Vol 16, No 31, 2023 1089
연구결과조사된 지역및의료기관 종에따른일반촬영장치
와유방촬영장치의분포현황은,일반촬영장치의경우상급종
합병원이27개소(7%), 종합병원이66개소(17%),병‧의원이
289개소(76%),유방촬영장치의경우상급종합병원이14개소
(10%),종합병원이35개소(26%), 병‧의원이 86개소(64%)
이다.국내2019년 연구에서는일반촬영의경우 상급종합병
원이23개소(22%),종합병원이 51개소(50%),병‧의원이
29개소(28%),유방촬영장치의경우 상급종합병원이29개소
(16%),종합병원이97개소(56%), 병‧의원이 50개소(28%)
를대상으로측정이이뤄졌다[3,4].상급종합병원과종합병원
급의의료기관에서는 의료방사선사용의정당화및최적화과
정에대한의료진들의인식이상대적으로병‧의원급의의료
기관에비해높을 것으로 예상되며,방사선피폭선량 모니터
링시스템도입및영상품질을바탕으로한검사조건의주기
적인검토또한 병‧의원급에비해높은 빈도로실시되고있
을것으로생각된다.
국내이전
DRL
연구에서는일반촬영의 경우상급종합병
원과종합병원을합한 비율이72%이며[3],유방촬영의경우
는그비율이 84%인반면[4],본 연구에서는 일반촬영의경
우27%,유방촬영의 경우36%로병‧의원급에서의 측정 비
율이훨씬더높아졌다.연구 초반에측정대상의료기관의종
별비율을설계할 당시에는선행연구와 유사한비율을목표
로하였다.그러나본연구의 측정대상기관을검사기관에장
치검사를의뢰한의료기관으로하다 보니,측정을실시할의
료기관의종별을미리확인하기어려운점이있었다.또한,의
료기관에서검사의뢰가들어온이후에해당기관의동의를얻
어
DRL
조사를실시할수밖에없는현실이었다.이에따라선
행연구와측정대상 의료기관종별비율에 차이가 발생했으
며,선행연구보다상대적으로병‧의원급의데이터가많이포
함되었다.전반적으로국내이전
DRL
과비교하여본연구결
과에서증가양상을 보인것은,상대적으로 병‧의원급의의
료기관에서의료방사선사용의정당화/최적화에 대한인식이
부족한경향이반영되었을 것으로 생각된다.따라서추후 정
책적으로이들기관에 대한의료방사선사용의 정당화및최
적화,
DRL
의활용방안과관련한홍보및교육이 반드시필요
할것으로보인다.
추후
DRL
을갱신함에있어서는실제임상환경을보다현
실적으로반영하는것이중요하다.미국에서는
ACR
Dose
in-
dex
registry
라는국가선량저장소를운영하고 있으며,컴퓨터
단층촬영(
computed
tomography
)에서의료용디지털영상통
신표준(
Digital
Imaging
and
Commnunications
in
Medicine
,
DICOM
)
Dose
Structured
Report
를기반으로선량정보값을
자동으로추출하여데이터베이스화 하고있다[9].일반촬영
및유방촬영에있어서도영상의
DICOM
Header
에검사조건,
조사야면적,조사선량값등이이미기록되고있다[9].따라서
미국의경우와같이국내에서도국가
DRL
을조사하는데있
어실제측정과병행하여국가선량저장소가운영될수있도록
대응체제를갖추어야할것이라고생각된다.
Declarations
Ethics
Statement
:
Not
applicable
.
Funding
Source
:
Korea
Disease
Control
and
Prevention
Agency
,
Policy
research
service
project
(20220407
A
2
B
-00).
Acknowledgments
:
We
would
like
to
thank
all
the
inspec-
tion
attendants
of
the
inspection
agency
who
conducted
the
표 3. 유방촬영의
diagnostic
reference
level
검사종류 팬텀(두께/유선)3사분위 ESD (mGy) 3사분위 AGD (mGy)
CC ACR
phantom
(4.2
cm
/50%) 8.40 1.56
CC
=
craniocaudal
;
ACR
=
American
College
of
Radiology
;
ESD
=
entrance
surface
dose
;
AGD
=
average
glandular
dose
.
www.phwr.org Vol 16, No 31, 2023
109 0
DRL
investigation
on
site
and
the
medical
institution
officials
who
responded
to
the
investigation
.
Conflict
of
Interest
:
The
authors
have
no
conflicts
of
inter-
est
to
declare
.
Author
Contributions
:
Conceptualization
:
YSY
,
JWG
,
BYL
.
Data
curation
:
YSY
,
HMP
.
Formal
analysis
:
YSY
,
HMP
.
Funding
acquisition
:
YSY
.
Investigation
:
YSY
,
HMP
.
Methodology
:
YSY
,
HMP
.
Project
administration
:
JHW
,
SKS
,
JWG
.
Resources
:
YSY
,
HMP
.
Software
:
JHW
,
SKS
.
Supervision
:
JWG
,
BYL
.
Validation
:
YSY
.
Visualization
:
HMP
.
Writing
–
original
draft
:
HMP
.
Writing
–
review
&
editing
:
YSY
,
JHW
,
JWG
.
References
1.
International
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on
Radiological
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of
the
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on
Radiological
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on
Ra-
diological
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;2007.
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Vaño
E
,
Miller
DL
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Martin
CJ
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reference
levels
in
medical
imaging
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on
Radiological
Protection
;2017.
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Korea
Disease
Control
and
Prevention
Agency
.
Guideline
for
diagnostic
reference
levels
:
general
radiography
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Korea
Disease
Control
and
Prevention
Agency
;2019.
4.
Korea
Disease
Control
and
Prevention
Agency
.
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for
diagnostic
reference
levels
:
mammography
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Korea
Dis-
ease
Control
and
Prevention
Agency
;2019.
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of
Health
and
Wel fa re
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of
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and
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No
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Manage-
ment
of
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able
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https
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0%
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B
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EC
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D
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EC
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E
%
A
5%
EC
%
B
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EC
%9
D
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EC
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E
C
%
A
0%84%
EA
%
B
4%80%
EB
%
A
6%
AC
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EC
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EA
%
B
4%80%
ED
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EA
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B
7%9
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EC
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B
9%99
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HM
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oriented
medical
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safety
management
[
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Korea
University
;2021.
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Kim
HJ
,
Gil
JW
,
Lee
BY
,
Lee
HK
.
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of
diagnostic
X
-
ray
equipment
in
the
Republic
of
Korea
,2020.
Public
Health
Wkly
Rep
2 021;14:3329 -36.
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Korea
Disease
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and
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Agency
.
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ra-
diation
safety
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manual
in
2021.
Korea
Disease
Control
and
Prevention
Agency
;2021.
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Yoon
SW
.
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of
establishment
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and
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;2023
Feb
.
Report
No
.:11-1790387-000738-01.
www.phwr.org Vol 16, No 31, 2023 1091
Introduction
For diagnosis and treatment of diseases, patient dose for
medical radiation are not limited. In general, the “as low as
reasonably achievable” (ALARA) principle is implement-
ed to moderate the radiation dose to which patients are ex-
posed. ALARA is commonly achieved through justification
and optimization [
1
]. Justification, mainly done by physi-
cians, is defined as the process of determining that radiological
examination is essential for the diagnosis and treatment of a
patient’s disease [
1
]. The patient dose is determined by ex-
amining the conditions (e.g., voltage, current, and irradiation
time) required for the irradiation process. Therefore, once jus-
tified, these conditions should be optimized for each type of
imaging method. During the optimization process, a diagnos-
tic reference level (DRL) is commonly used [
2
].
A DRL is a tool recommended by the International
Commission on Radiological Protection and the International
Korean Diagnostic Reference Level for General Radiography and
Mammography in 2022
YongSu Yoon1, HyeMin Park2, JongHun Won3, SeungKi Song3, JongWon Gil3, ByeongYoung Lee3*
1Department of Radiological Science, Dongseo University, Busan, Korea,
2Department of Radiology, Masan University, Changwon, Korea,
3Division of Medical Radiation, Bureau of Healthcare Safety and Immunization,
Korea Disease Control and Prevention Agency, Cheongju, Korea
ABSTRACT
There
are
no
specific
limits
on
patient
dose
for
medical
radiation
.
However
,
optimizing
patient
dosage
is
crucial
,
and
diagnostic
reference
levels
(
DRLs
)
serve
as
valuable
tools
for
this
purpose
.
DRLs
can
be
set
at
the
national
,
regional
,
or
institutional
level
,
and
regular
revisions
are
recommended
.
In
the
Republic
of
Korea
,
the
Korea
Disease
Control
and
Prevention
Agency
(
KDCA
)
provides
national
DRLs
.
This
study
aimed
to
derive
updated
national
DRLs
for
general
radiography
and
mammography
through
a
nationwide
survey
conducted
in
2022.
To
derive
this
,
a
research
method
was
designed
to
collect
data
from
diagnostic
radiation
generator
inspection
institutions
.
The
research
team
organized
and
analyzed
these
data
.
Data
for
DRL
derivation
were
collected
from
four
inspection
institutions
registered
with
the
KDCA
,
resulting
in
a
larger
dataset
compared
to
previous
studies
.
Particularly
,
a
large
amount
of
data
from
hospitals
and
clinics
was
included
to
ensure
that
the
derived
DRLs
reflect
the
current
reality
.
By
maintaining
this
research
method
,
future
nationwide
surveys
on
DRLs
are
expected
to
be
conducted
more
easily
and
with
greater
diversity
.
Key
words
:
Radiography
;
Mammography
;
Diagnostic
reference
level
;
Patient
dose
;
Optimization
*Corresponding author: ByeongYoung Lee, Tel: +82-43-719-7511, E-mail: lkd@korea.kr
www.phwr.org Vol 16, No 31, 2023
109 2
Atomic Energy Agency for the optimization of medical radia-
tion exposure [
2
]. The DRL is regularly reported through sur-
veys and dosimetric analysis in many countries and regions
worldwide.
Typically, the DRL for each imaging method is set at the
third quartile values (
75
%) of data from survey results. The
concept of a DRL is different from dose constraint, which
limits individual radiation exposure for preventive purposes
through source-centered assessment, or a dose limit that must
not be exceeded to ensure patient safety. The DRL is not a set
limit on medical radiation exposure for diagnosis and treat-
ment, but “a reference value” that is used for the optimization
of radiation doses [
2
].
Facilities that use radiation doses exceeding the DRL are
asked to revise their dose optimization. In contrast, facilities
that use radiation doses much lower than the DRL need to
assess whether the radiographic images acquired at that level
provide useful diagnostic information.
Periodically, information on the concept and utilization of
DRL, justification of radiation treatment for the improvement
of public health, and optimization of radiation doses need to be
provided to medical staff and related researchers in radiology.
Accordingly, national DRLs are set by many nations world-
wide as a basis for the optimization of radiation doses to pa-
tients. In the Republic of Korea, DRLs have been set for chest
radiography and mammography in adults in
2007
, and na-
tional DRLs have been prepared for different types of radiogra-
phy [
3
,
4
]. In
2017
and
2018
, studies have been conducted to
set national DRLs for general radiography and mammography
in both children and adults. Subsequently, in
2019
, the Korea
Disease Control and Prevention Agency (KDCA) published
guidelines for DRLs. In these studies and guidelines, general
radiography included imaging of the head, chest, abdomen,
spine, pelvis, and extremities [
3
,
4
].
This study investigated and organized data on radiation
doses to patients in Korean medical institutions in
2022
and
presents a new national DRL for general guidelines on radi-
ography and mammography that can be used for the optimi-
zation of examination conditions and radiation doses to pa-
tients. In particular, this study investigated DRLs by using a
novel method. Previously, a single research team conducted all
steps to establish DRLs. In our study, to increase the reliability
of DRLs through more extensive data collection, two separate
teams were involved: the DRL investigation method estab-
lishment and data analysis team and the on-site investigation
team. Using this novel survey method, data were collected and
analyzed to propose new national DRLs.
Key
messages
①
What
is
known
previously
?
Patient
dosage
should
be
optimized
following
the
“
as
low
as
reasonably
achievable
”
principle
.
To
achieve
this
,
di-
agnostic
refer
ence
levels
(
DRLs
)
are
established
.
DRLs
is
internationally
recommended
to
periodically
revising
.
②
What
new
information
is
presented
?
This
study
enhanced
the
investigation
method
for
DRLs
compared
to
previous
research
.
It
collaborated
with
in-
spection
institutions
to
collect
a
large
dataset
of
517
gen-
eral
radiography
and
mammography
equipment
.
This
approach
significantly
increased
the
reliability
of
the
sta-
tistical
analysis
used
to
derive
the
DRLs
.
③
What
are
implications
?
Continuous
active
promotion
through
DRLs
are
neces-
sary
for
achieving
patient
dose
optimization
.
www.phwr.org Vol 16, No 31, 2023 1093
Methods
1. Diagnostic Radiation Equipment Inspection and
DRL Investigation Procedures
The “Rules on safety management of diagnostic radia-
tion equipment,” an ordinance of the Ministry of Health and
Welfare under Article
37
of the Medical Act, stipulate matters
necessary to prevent potential harm to patients and radiation-
related workers and to promote adequate medical treatment
by safely managing diagnostic radiation equipment (DRE) in-
stalled and operated by medical institutions [
5
].
As per the rules, the founder or manager of a medical insti-
tution must undergo DRE inspection by an inspection agency
before using DRE and every subsequent
3
years [
5
,
6
]. The in-
spection agencies are certified and registered with the KDCA.
As shown in Table
1
, a total of five inspection agencies are
currently in operation in the Republic of Korea. Of these, four
agencies, excluding the ROK Army Unit
2879
, have branches
nationwide to conduct inspections at all medical institutions
that use DRE [
7
,
8
].
The founder or manager of a medical institution who wish-
es to inspect a DRE must apply for inspection to the head of
the inspection agency. The agency that receives the applica-
tion must issue an inspection report to the applicant after con-
ducting an inspection. Then, the results must be submitted to
the Director of the KDCA within
1
month from the date of
inspection or evaluation [
5
,
8
].
This policy study was designed to conduct DRE inspec-
tion and dosimetry simultaneously for DRL investigation to
increase the accuracy and data collection efficiency of national
DRLs. A total of four inspection agencies, excluding one agen-
cy that conducts self-inspection, participated in this study and
conducted an on-site investigation of DRLs.
DRL investigation processes used in this study are shown
in Figure
1
. When the founder or manager of a medical institu-
tion applied for DRE inspection, the inspection agency request-
ed cooperation in DRL research. Once the medical institution
of interest accepted the request, an additional DRL investiga-
tion was conducted after the DRE inspection. Then, the inspec-
tion agency provided the collected data to the research team,
which were then analyzed to establish new national DRLs for
general radiography and mammography. Additionally, to pro-
vide adequate feedback to the medical institutions that coop-
erated in this study, feedback data that included a comparison
between the derived DRL and measured values were provided
Table
1.
Status
of
diagnostic
radiography
equipment
inspection
institution
(
as
of
November
17, 2022)
Registration No. Institution name Location
Inspection
2 2-1
Army
Unit
2879(
self
-
inspection
)-
Inspection
2 2-2
Korea
Institute
of
Medical
Technology Jungnang
-
gu
,
Seoul
Inspection
22-3
Korea
Institute
of
Medical
Device
Assistant Bundang
-
gu
,
Seongnam
-
si
Inspection
2 0 -1
Korea
Institute
of
Test ing
&
Examination Bundang
-
gu
,
Seongnam
-
si
Inspection
2 0-2
Central
Technology
Inspection
Institute Buk
-
gu
,
Daegu
KDCA-division of
medical radiation
Inspection institution Data analysis tea
(our research team)
Inspection
request
Request for
cooperationin
DRL survey
Providing feedback on the
newly derived DRL forthe
respective medical institution
Derive the newly DRL and
transfer feedback datafor
medical institution
DRL survey data transfer
Medical institution
owner or administrator
Figure
1.
Flowchart
of
national
DRL
investigation
in
this
study
DRL
=
diagnostic
reference
level
;
KDCA
=
Korea
Disease
Control
and
Prevention
Agency
.
www.phwr.org Vol 16, No 31, 2023
109 4
to each medical institution.
2. Development of Survey for DRL Data
Collection
Through discussions with inspection agencies that conduct
on-site investigations, a data collection survey form was devel-
oped to derive new national DRLs. The survey consisted of four
main areas: medical institution information, DRE information,
image-processing equipment information, and imaging infor-
mation per inspection item (Figure
2
).
Information regarding the medical institution included the
region, type of medical institution, presence of a dose man-
agement system owned by the medical institution, number of
general radiography instruments, number of mammography
instruments, and number of image processing devices. Regions
were divided into Seoul, Incheon, Gyeonggi-do, Gangwon-do,
A
B
C
D
Figure
2.
Developed
survey
form
for
diagnostic
reference
level
in
vestigation
(
A
)
Medica l
institution
information
entry
items
.(
B
)
General
radiography
and
mammography
equipment
information
entry
items
.(
C
)
Image
proces
sing
device
information
entry
items
.(
D
)
Exposure
condition
and
dose
information
for
each
examination
pro
tocol
in
general
radiography
and
mammo
graphy
.
CR
=
computed
radiography
;
DR
=
digital
radiography
;
DAP
=
dose
area
product
;
DRL
=
diagnostic
reference
level
;
ESD
=
entrance
surface
dose
;
AP
=
anterior
-
posterior
;
PA
=
posterior
-
anterior
;
LAT
=
lateral
;
SID
=
source
to
image
receptor
distance
;
AEC
=
automatic
exposure
control
system
;
Mo
=
molybdenum
;
Rh
=
rhodium
;
Al
=
aluminum
;
Cu
=
copper
;
AGD
=
average
glandular
dose
;
HVL
=
half
value
layer
;
mAs
,
milli
ampere
second
.
www.phwr.org Vol 16, No 31, 2023 1095
Chungcheong-do, Jeolla-do, Gyeongsang-do, and Jeju-do. The
type of medical institution was classified into tertiary general
hospital, general hospital, and hospital/clinic. The presence of
a dose management system owned by the medical institution
was answered as yes or no, and image-processing equipment
was classified into Film/Screen, computed radiography (CR)
system, and digital radiography (DR) system.
General radiography equipment information included the
manufacturer, model name, date of manufacture, type of high
voltage generator, inherent filters, recent equipment inspection
results, and presence of dose area product (DAP). The type of
high voltage generator was divided into single-phase generator,
three-phase generator, and inverter. Inherent filters evaluated
the type of equipment filtering material, such as aluminum (Al)
or copper (Cu) in units of mm. Recent equipment inspection
results were indicated as “passed” or “failed,” and in the case
of a failure result, the failure item was specified. The purpose
of this item was to ensure the reliability of the data collected in
this study, based on findings that dose reproducibility is a suit-
able inspection item [
5
,
6
]. The presence of DAP was answered
as yes or no. If a DAP was available, the value measured by the
DAP was also recorded. In contrast, if a DAP was not available,
but the DAP value was displayed on the console, the indicated
value was recorded to determine whether the value was mea-
sured or derived by the manufacturer after calculations.
Mammography equipment information included the name
of the manufacturer, model name, date of manufacture, type
of high voltage generator, target, inherent filters, recent equip-
ment inspection results, and attachment of a dosimeter. The
type of high-voltage generator was divided into a single-phase
generator, three-phase generator, and inverter, and the target
was divided into molybdenum (Mo), rhodium (Rh), tungsten
(W), and others. Inherent filters were divided into Al, beryl-
lium, W, Mo, Rh, or Cu, in units of mm.
Image-processing equipment information included the
same information as for general radiography and mammogra-
phy equipment: type, name of the manufacturer, model name,
and dose information. The type of image-processing equip-
ment was classified into Film/Screen, CR system, and DR sys-
tem. Dose information referred to the value displayed on the
console during imaging. Dose information was classified into
none, DAP, entrance surface dose (ESD), and exposure index
(EI) for general radiography, and none, ESD, entrance sur-
face exposure (ESE), average glandular dose (AGD), and EI for
mammography. When several values of dose information were
displayed, all values were recorded, in plural.
Both general radiography and mammography required the
following imaging information for each inspection item: tube
voltage, tube current, irradiation time, mAs, irradiation field
(horizontal and vertical), source-to-image receptor distance,
grid ratio, automatic exposure control system, an additional fil-
ter, and dose information. The first nine items were values that
were used in the medical institutions for each inspection item,
while dose information was defined as the value measured by
the dosimeter used by the inspection agency under the imaging
conditions. If the dosimeter displayed the dose information,
both the measured and displayed values (general radiography:
DAP, ESD, or EI; mammography: ESD, ESE, AGD, or EI) were
recorded. For general radiography, items to which automatic
exposure control (AEC) was applied were measured using a
water phantom (
20
×
20
×
20
cm
3
) owned by the inspection
agency. For mammography, items to which the AEC was ap-
plied were measured using the American College of Radiology
(ACR) phantom. In mammography, the measured AGE value
www.phwr.org Vol 16, No 31, 2023
109 6
was calculated using the measured ESD value, irradiation time,
and half-value layer.
General radiography was further specified into two types
for pediatrics (age:
5
–
10
years) and adults. In pediatrics,
13
test types, including skull anterior-posterior (AP), chest poste-
rior-anterior (PA), and chest lateral (LAT) views, were investi-
gated. In adults,
19
test types, including the
13
test types used
in pediatrics and, additionally, cervical spine (C-Spine) AP and
LAT, thoracic spine (T-Spine) AP and LAT, and lumbar spine
(L-Spine) AP and LAT views, were investigated.
3. DRL Data Collection and Analysis
The inspection agencies visited medical institutions that
agreed to cooperate in DRL research. Using the survey form,
medical institution information, DRE information, examina-
tion conditions by imaging type, and measured dose values
were recorded. As shown in Figure
3
, the research team visited
the sites regularly to assess potential on-site difficulties and to
A
B
Figure
3.
Diagnostic
reference
level
(
DRL
)
investigation
process
of
the
inspection
institutions
(
A
)
DRL
investigation
process
for
gene
ral
radiography
equipment
.(
B
)
DRL
investigation
process
for
mam
-
mography
equipment
.
www.phwr.org Vol 16, No 31, 2023 1097
secure consistent data.
DRL values collected through the inspection agencies were
raw data that had not undergone processing, such as the exclu-
sion of outliers. To obtain accurate DRL statistical results, data
statistics and comparative analysis were conducted by a statisti-
cal analysis expert. The minimum, maximum, mean, median,
and third quartile values were derived from the distribution of
the measured dose values for each imaging type. Among these
values, the third quartile values were selected as DRLs for dif-
ferent imaging types [
2
]. Additionally, doses were compared
by medical institution information, DRE information, and im-
aging conditions acquired from the survey form.
Results
In this study, conducted to establish national DRLs for
general radiography and mammography, data on
382
general
radiography and
135
mammography instruments were col-
lected from
454
medical institutions. DRE distribution by the
type of medical institution was as follows. Approximately
7
%,
17
%, and
76
% of general radiography instruments were in ter-
tiary general hospitals, general hospitals, and hospitals/clinics,
respectively. For mammography instruments,
10
%,
26
%, and
64
% were in tertiary general hospitals, general hospitals, and
hospitals/clinics, respectively.
As shown in Tables
2
and
3
, analysis of the collected data
allowed the derivation of national DRLs for different imaging
types in general radiography and mammography. The results
for general radiography were as follows. In pediatric radiog-
raphy of
5
-year-old patients, ankle AP imaging had the low-
est ESD value of
0
.
16
mGy, while abdomen AP imaging had
the highest ESD value of
1
.
40
mGy. In pediatric radiography
Table
2.
DRL
for
general
radiography
Protocol ESD (mGy) DAP (mGy‧cm2)
5-
year
-
old
Skull
AP
1.01 515.30
Chest
PA
0.32 405.82
Chest
LAT
0.75 912.41
Abdomen
AP
1.40 1,552 .78
Pelvis
AP
1.17 1, 30 5.59
Shoulder
AP
0.5 9 36 5.58
Humerus
AP
0.39 526.63
Elbow
AP
0.19 73.30
Hand
PA
0.20 47.4 8
Hip
Joint
AP
1.07 1,163.78
Femur
AP
0.60 733.31
Knee
AP
0.26 162.67
Ankle
AP
0.16 63.40
10-
year
-
old
Skull
AP
1.59 803.52
Chest
PA
0.47 613.36
Chest
LAT
1.06 1,231.84
Abdomen
AP
2.28 2,418.4 3
Pelvis
AP
2.08 2 ,2 08.59
Shoulder
AP
0.83 485.89
Humerus
AP
0.66 881.18
Elbow
AP
0.27 103.67
Hand
PA
0.18 69.79
Hip
Joint
AP
1.9 0 1,9 61.77
Femur
AP
0.9 7 1,152 .94
Knee
AP
0.42 256.08
Ankle
AP
0.26 102.62
Adult
Skull
AP
2.55 1,226.26
Chest
PA
0.68 769.23
Chest
LAT
1.55 1,592.29
Abdomen
AP
3.80 3,645.52
Pelvis
AP
3.70 3, 337.3 4
C
-
Spine
AP
1.36 588.4 4
C
-
Spine
LAT
1.22 527.47
T
-
Spine
AP
3.70 3,5 51.99
T
-
Spine
LAT
5.86 5,574.46
L
-
Spine
AP
4.83 4,653.46
L
-
Spine
LAT
8.49 8 ,21 3.78
Shoulder
AP
1.55 636.23
Humerus
AP
0.9 3 912 .15
Elbow
AP
0.42 134 .99
Hand
PA
0.27 91.61
Hip
Joint
AP
3.22 2,079.74
Femur
AP
1.88 1,489.5 5
Knee
AP
0.7 3 314.57
Ankle
AP
0.5 0 147. 21
DRL
=
diagnostic
reference
level
;
ESD
=
entrance
surface
dose
;
DAP
=
dose
area
product
;
AP
=
anterior
-
posterior
;
PA
=
posterior
-
anterior
;
LAT
=
lateral
;
C
-
Spine
=
cervical
spine
;
L
-
Spine
=
lumbar
spine
;
T
-
Spine
=
thoracic
spine
.
www.phwr.org Vol 16, No 31, 2023
109 8
of
10
-year-old patients, hand PA imaging had the lowest ESD
value of
0
.
18
mGy, while abdomen AP imaging had the high-
est ESD value of
2
.
28
mGy. In adults, hand PA imaging had
the lowest ESD value of
0
.
27
mGy, while L-Spine LAT imag-
ing had the highest ESD value of
8
.
49
mGy. Mammography
showed an ESD value of
8
.
40
mGy and an AGD value of
1
.
56
mGy.
Radiation dose distribution was compared by the type of
medical institution. For general radiography, hospitals/clinics
showed the highest dose value for all types of imaging in both
pediatric and adult radiography, followed by general hospitals
and tertiary general hospitals. General mammography present-
ed a pattern similar to that of radiography.
Discussion
This study aimed to prepare DRLs for different imaging
types of general radiography and mammography, according
to patients’ age groups. Herein, we collected data on radiation
doses to which patients are exposed in medical institutions and
presented national DRLs that can be used for the optimization
of examination conditions and radiation doses, thereby estab-
lishing data that can be used to prepare policies on medical ra-
diation safety management.
The biggest difference between our study and previ-
ous studies on DRL, which have been updated periodically
by the KDCA, involved the DRL investigation method used.
In previous studies, a single research team investigated DRL
suggestions (examination protocol), target equipment and re-
gion, distribution of equipment by type of institution, and do-
simetric measurements. In contrast, the research team of this
study established investigation items for DRL preparation and
dose measurement. On-site measurements at medical institu-
tions were conducted by DRE inspection agencies under the
on-site guidance of the research team. After the measurements
had been completed, the acquired data were statistically ana-
lyzed to present national DRLs.
Compared to the existing research methods, the most no-
table feature of this study was the considerable increase in the
number of measurements (number of medical institutions
surveyed nationwide:
454
, number of general radiography
and mammography equipment:
517
). The greater number of
samples analyzed in this study increased the reliability of the
results. Moreover, the DRE analyzed in this study satisfied the
inspection criteria that were per the regulations, further reduc-
ing the inaccuracy of measurement results caused by the qual-
ity control level of equipment. In the process of requesting,
receiving, and conducting DRE inspections, some difficulties
in obtaining cooperation for DRL investigation from medical
institutions were encountered, and many institutions tended to
have no prior knowledge about DRLs. However, the findings
of this study may help to widen efforts to optimize radiation
doses for patients and to spread information on DRLs, which
has mostly been available only to general hospitals and larger
hospitals, to more types of medical institutions in the Republic
of Korea. Therefore, it is expected that subsequent national
Table
3.
DRL
for
mammography
Protocol Phantom (thickness/mammary gland) 3rd quartile ESD (mGy) 3rd quartile AGD (mGy)
CC ACR
phantom
(4.2
cm
/50%) 8.40 1.56
CC
=
craniocaudal
;
ACR
=
American
College
of
Radiology
;
ESD
=
entrance
surface
dose
;
AGD
=
average
glandular
dose
.
www.phwr.org Vol 16, No 31, 2023 1099
DRL investigations may be more sophisticated and widespread
than previously.
The DRL suggested in this study generally tended to be in-
creased when compared with national DRLs conducted in the
Republic of Korea in
2017
and
2018
[
3
,
4
]. Such differences
may be attributed to the measurement methods used. The
findings of our study are substantial, as the greater sample size
has relatively higher representativeness. Herein, general radi-
ography and mammography equipment distribution, accord-
ing to the type of medical institution and region, was as fol-
lows:
27
(
7
%),
66
(
17
%), and
289
(
76
%) general radiography
instruments were located in tertiary general hospitals, general
hospitals, and hospitals/clinics, respectively, and
14
(
10
%),
35
(
26
%), and
86
(
64
%) mammography instruments were lo-
cated in tertiary general hospitals, general hospitals, and hos-
pitals/clinics, respectively. In a domestic study conducted in
2019
,
23
(
22
%),
51
(
50
%), and
29
(
28
%) general radiography
instruments were found in tertiary general hospitals, general
hospitals, and hospitals/clinics, respectively, while
29
(
16
%),
97
(
56
%), and
50
(
28
%) mammography instruments were lo-
cated in tertiary general hospitals, general hospitals, and hospi-
tals/clinics, respectively [
3
,
4
]. Medical staff in tertiary general
hospitals and general hospital-level medical institutions are ex-
pected to have a relatively higher awareness of the justification
and optimization process of medical radiation use and conduct
more frequent periodic reviews of examination conditions
based on image quality, using radiation-exposure dose moni-
toring systems, than do those in hospitals/clinics.
In previous domestic studies on DRLs, the combined rate
of tertiary general hospitals and general hospitals was
72
%
for general radiography [
3
] and
84
% for mammography
[
4
]. Concurrently, in our study, the combined rate of tertiary
general hospitals and general hospitals was
27
% for general
radiography and
36
% for mammography, indicating an in-
creased rate of measurements in hospitals/clinics. Initially,
when the ratio of the types of medical institutions was designed
for this study, we aimed to achieve a ratio similar to that of pre-
vious studies. However, as the target institutions were those
that requested equipment inspection, we encountered diffi-
culties in assessing the type of medical institution before the
investigation. Additionally, we had to ask for the cooperation
of medical institutions that requested inspections to conduct
a DRL investigation. As a result, our study differed markedly
from previous studies in terms of the type of medical institu-
tion included, and relatively more data from hospitals/clinics
were included in our study. The overall increase in DRLs in
our study as compared to those in previous findings may re-
flect the relative lack of awareness of radiation use justification
and optimization in hospitals/clinics. Therefore, future policies
must include education on the justification and optimization
of medical radiation use and the utilization of DRLs.
When reviewing DRLs in the future, clinical environment
settings should be reflected more realistically. In the US, the
ACR Dose Index Registry, a national dose registry, is available.
Dose information values are automatically extracted and stored
in a database using Digital Imaging and Communications in
Medicine (DICOM) structured reports of doses [
9
]. Data, such
as examination condition, irradiation field area, and radiation
dose, are recorded in the DICOM header of images for general
radiography and mammography [
9
]. Therefore, to establish
more refined national DRLs, a sophisticated response system
that measures radiation dose values during DRL investigation
must be prepared to establish a national dose index registry.
www.phwr.org Vol 16, No 31, 2023
110 0
Declarations
Ethics
Statement
:
Not
applicable
.
Funding
Source
:
Korea
Disease
Control
and
Prevention
Agency
,
Policy
research
service
project
(20220407
A
2
B
-00).
Acknowledgments
:
We
would
like
to
thank
all
the
inspec-
tion
attendants
of
the
inspection
agency
who
conducted
the
DRL
investigation
on
site
and
the
medical
institution
officials
who
responded
to
the
investigation
.
Conflict
of
Interest
:
The
authors
have
no
conflicts
of
inter-
est
to
declare
.
Author
Contributions
:
Conceptualization
:
YSY
,
JWG
,
BYL
.
Data
curation
:
YSY
,
HMP
.
Formal
analysis
:
YSY
,
HMP
.
Funding
acquisition
:
YSY
.
Investigation
:
YSY
,
HMP
.
Methodology
:
YSY
,
HMP
.
Project
administration
:
JHW
,
SKS
,
JWG
.
Resources
:
YSY
,
HMP
.
Software
:
JHW
,
SKS
.
Supervision
:
JWG
,
BYL
.
Validation
:
YSY
.
Visualization
:
HMP
.
Writing
–
original
draft
:
HMP
.
Writing
–
review
&
editing
:
YSY
,
JHW
,
JWG
.
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