March 24, 2022
JCR position statement
JCR statement on appropriate workload of radiologists
In order to maintain the quality of radiology services, it is ideal to limit the number ofradiologists’ reports to less than 4 cases per hour of uninterrupted reading time (i.e.
protected time excluding activities such as scheduling, conferences, and consultations).
Securing a sufficient number of board-certified radiologists will be vital for providing
proper radiological services.
Note: The above mentioned number applies to the interpretation of CT, MRI, and PET-CT, but notplain films.
●Comments
The roles of radiologists include, but are not limited to, deciding on the appropriate
imaging methods, managing the optimal protocols, giving instructions to technologists, and writing
reports for the examinations performed. For instance, when choosing the appropriate
examinations, radiologists have to balance multiple factors, such as invasiveness of theexaminations (e.g. radiation exposure) and diagnostic ability of the modalities. They also have tocarefully detect subtle but significant findings, and then make an interpretation based on theclinical data. They have to provide this information to the referring physicians (and sometimes tothe patients) in a timely fashion, so that it will lead to proper treatment. In addition, it is important
to monitor whether the referring physicians fully understand the contents of the reports andwhether they correctly reflect them in the treatment process.
According to the draft proposal of the Japanese Health Insurance Federation for Surgery(Gaiho-ren), image interpretation of CT/MRI takes on average 14.6 min per caseI. Since the services
provided by radiologists include complex processes, as mentioned earlier, it will be difficult tomaintain the quality of the whole process if their workload exceeds 4 cases per hour. This number
will be further reduced in teaching institutions (i.e. academic or training hospitals).
Many previous studies have reported the adverse effect of shortening the interpretation
time as well as of the excessive volume of interpretationsII. Moreover, unread radiology reports
have become a serious social problem, leading to increased demand for swift reportingIII.
In 2019, CT/MRI examinations had increased by 18% from 2015. Similarly, the number ofrequests for Added fees for Radiological Management of Imaging-studies (ARMI) had increased by21%. On the other hand, the number of radiologists had increased only by 10% during the sameperiodIV.

With technological advances of CT equipment, the number of slices per case has
increased dramaticallyV. It has been also pointed out that the number of CT and MRI studies readannually per radiologist in Japan is 3–4 times greater than in Western developed countriesVI. Inaddition, the required report turnaround time (RTT) has recently become shorter to meet the rulesof ARMI, which makes it even more difficult to assure the quality of our image interpretationVII.
Under such circumstances, it is becoming increasingly important to check and confirm
whether the messages of our report containing important or unexpected findings actually reach thereferral physicians. Checking if there are any unread radiology reports might be also one of ourroles. In addition, holding regular conferences/consultations between radiologists and clinicians isimportant in improving the quality of practice. These processes will be also important from a
medical safety standpointVIII.
We have to bear in mind that the number of CT exams in Japan per capita is 3 times
greater than in the United Kingdom, and 1.8 times greater than in Germany. To assure medical
quality and safety, it is an obligation of the hospital administrators to secure a sufficient number ofboard-certified diagnostic radiologists to handle the overwhelming volume of workload.

References
1)

Radiology ver1.5, Draft proposal of Japanese Health Insurance Federation for Surgery 2022,
Igakutushinsya, 2021

2)

E. Sokolovskaya, et al: The Effect of Faster Reporting Speed for Imaging Studies on the Numberof Misses and Interpretation Errors: A Pilot Study. J Am Coll Radiol 12: 683-688, 2015

3)

S. H. Patel, et al: Risk Factors for Perceptual-versus-Interpretative Errors in Diagnostic
Neuroradiology. AJNR Am J Neuroradiol 40: 1252-1256, 20194)

The Japan Council for Quality Health Care. Medical safety information No 63 Inadequte checks
concerning diagnostic imaging reports. [cited] Available from: https://www.medsafe.jp/pdf/med-safe_63.pdf. 20125)

The Japan Council for Quality Health Care. Medical safety information No 138 Inadequtechecks concerning diagnostic imaging reports (1st follow-up report). [cited] Available from:https://www.med-safe.jp/pdf/med-safe_138.pdf. 20186)

The result of a questionnaire for reforming workstyle in radiology 2018. JCR News 226
Supplement, 20187)

Y. Nakajima, et al: Radiologist supply and workload: international comparison--Working Groupof Japanese College of Radiology. Radiat Med 26: 455-465, 2008

8)

K. K. Kumamaru, et al: Global and Japanese regional variations in radiologist potential
workload for computed tomography and magnetic resonance imaging examinations. Jpn J Radiol36: 273-281, 2018

9)

E. C. Dickerson, et al: In-Person Communication Between Radiologists and Acute CareSurgeons Leads to Significant Alterations in Surgical Decision Making. J Am Coll Radiol 13:
943-949, 2016

Required interpretation time can be found in the “Draft Proposal of Japanese Health Insurance
Federation for Surgery” 1).
I

A study reported that the average interpretation error rate at the faster speed was 26.6%, comparedwith 10% at normal speed 2). Another study showed that for neuroradiology cases, perception errors
occurred with interpreting an average of 6 cases per hour, while no errors occurred in interpreting anaverage of 5 cases 3).
II

Medical safety information reported by the Japan Council for Quality Health Care has repeatedly
given alerts about the self-interpretation made by non-radiologist physicians. This behavior leads toinadequate confirmation of the final results provided by the radiologists 4, 5).
III

This is based on the statistics for medical care activities in public health insurance by the Ministryof Health, Labour and Welfare from 2015 to 2019, before being influenced by the COVID-19
pandemic. CT examinations had increased by 22% from 2015 to 2019 (1,688,363 versus 2,057,175
exams), while MRIs increased by 12% in the same period (1,017,395 vs. 1,136,381 exams). In
contrast, board-certified diagnostic radiologists have increased only by 10% from 5,251 to 5,802 inthe same period.
IVA survey by JCR reported that the total number of slices for CT and MRI has doubled from 2010
to 2017. The number of examinations in the same period increased by 30% 6).
V

The workload of a radiologist (CT and MRI examinations) in Japan was 4.3 times higher than theOECD average in 2004 7). This overload remained unchanged in 2015 (3 to 4 times more CT andMRI exams per radiologist) 8). Kumamaru et al. reported that Japan had only one-third theradiologists per capita compared with the USA. Although the number of radiologists per capita inJapan is similar to Germany, the workload per German radiologist is one-third compared withJapanese radiologists.
VI

Acquisition of ARMI requires that 80% of radiology reports be completed and delivered to thereferral physician by the next business day. In 2019, the risk of faster interpretation times has been
pointed out within the “policy recommendations for the effective utilization of information of CTexams” issued by a working group in the Science Council of Japan.
VII

Dickerson et al. reported that in-person meetings with a radiologist led to changes in surgeons’impressions in many cases, which led to changes in medical and/or surgical planning 9). This study
emphasized the importance of in-person meetings between radiologists and referral physicians.
VIII