Elliot K. Fishman M.D.
Johns Hopkins Hospital

• A conservative estimate found that 5 percent of U.S. adults who seek outpatient care each year experience a diagnostic error.
• Postmortem examination research spanning decades has shown that diagnostic errors contribute to approximately 10 percent of patient deaths.
• Medical record reviews suggest that diagnostic errors account for 6 to 17 percent of hospital adverse events. 
• Diagnostic errors are the leading type of paid medical malpractice claims, are almost twice as likely to have resulted in the patient’s death compared to other claims, and represent the highest proportion of total payments. 
Improving Diagnosis in Healthcare
Committee on Diagnostic Error in Health Care
Erin P. Balogh, Bryan T. Miller, and John R. Ball, Editors 
Board on Health Care Services, Institute of Medicine
The National Academies Press, [2015]

“In reviewing the evidence, the committee concluded that most people will experience at least one diagnostic error in their lifetime, sometimes with devastating consequences. Despite the pervasiveness of diagnostic errors and the risk for serious patient harm, diagnostic errors have been largely unappreciated within the quality and patient safety movements in health care. Without a dedicated focus on improving diagnosis, these errors will likely worsen as the delivery of health care and the diagnostic process continue to increase in complexity.”
Improving Diagnosis in Healthcare
Committee on Diagnostic Error in Health Care
Erin P. Balogh, Bryan T. Miller, and John R. Ball, Editors 
Board on Health Care Services, Institute of Medicine
The National Academies Press, [2015]

“Perceptual or cognitive errors made by radiologists are a source of diagnostic error. In addition, incomplete or incorrect patient information, as well as insufficient sharing of patient information, may lead to the use of an inadequate imaging protocol, an incorrect interpretation of imaging results, or the selection of an inappropriate imaging test by a referring clinician. Referring clinicians often struggle with selecting the appropriate imaging test, in part because of the large number of available imaging options and gaps in the teaching of radiology in medical schools.” 
Improving Diagnosis in Healthcare
Committee on Diagnostic Error in Health Care
Erin P. Balogh, Bryan T. Miller, and John R. Ball, Editors 
Board on Health Care Services, Institute of Medicine
The National Academies Press, [2015]

“Human error is inevitable. Although we cannot eliminate human error, we can better measure the problem to design safer systems mitigating its frequency, visibility, and consequences. Strategies to reduce death from medical care should include three steps: making errors more visible when they occur so their effects can be intercepted; having remedies at hand to rescue patients; and making errors less frequent by following principles that take human limitations into account.” 
Medical error-the third leading cause of death in the US.
Makary MA, Daniel M
BMJ. 2016 May 3;353:i2139.

“ In the daily radiology practice, the rate of interpretation error is between 3% and 4%; however, of the radiology studies that contain abnormalities, the error rate is even higher, averaging in the 30% range.”
Fool Me Twice: Delayed Diagnoses in Radiology With Emphasis on Perpetuated Errors
Kim YW, Mansfield LT
AJR 2014;202:465-470

“ In our study, the majority of errors made were errors of underreading (42%), where the finding was simply missed.”
Fool Me Twice: Delayed Diagnoses in Radiology With Emphasis on Perpetuated Errors
Kim YW, Mansfield LT
AJR 2014;202:465-470

“The purpose of the study was to determine if increasing radiologist reading speed results in more misses and interpretation errors.”
The Effect of Faster Reporting Speed for Imaging Studies on the Number of Misses and Interpretation Errors: A Pilot Study.
Sokolovskaya E et al.
J Am Coll Radiol. 2015 Jul;12(7):683-8.

“ Reading at the faster speed resulted in more major misses for 4 of the 5 radiologists. The total number of major misses for the 5 radiologists, when they reported at the faster speed, was 16 of 60 reported cases, versus 6 of 60 reported cases at normal speed; P = .032. The average interpretation error rate of major misses among the 5 radiologists reporting at the faster speed was 26.6%, compared with 10% at normal speed.”
The Effect of Faster Reporting Speed for Imaging Studies on the Number of Misses and Interpretation Errors: A Pilot Study.
Sokolovskaya E et al.
J Am Coll Radiol. 2015 Jul;12(7):683-8.

“Our pilot study found a significant positive correlation between faster reading speed and the number of major misses and interpretation errors.”
The Effect of Faster Reporting Speed for Imaging Studies on the Number of Misses and Interpretation Errors: A Pilot Study.
Sokolovskaya E et al.
J Am Coll Radiol. 2015 Jul;12(7):683-8.

Background and Purpose: Medical errors can result in significant morbidity and mortality. The goal of our study is to evaluate correlation between shift volume and errors made by attending neuroradiologists at an academic medical center, using a large data set.
Materials and Methods: CT and MRI reports from our Neuroradiology Quality Assurance database (years 2014   2020) were searched for attending physician errors. Data were collected on shift volume, category of missed findings, error type, interpretation setting, exam type, clinical significance.
Conclusion: Errors were associated with higher volume shifts, were primarily perceptual and clinically significant. We need National guidelines establishing a range of what is a safe number of interpreted cross-sectional studies per day.
Impact of Shift Volume on Neuroradiology Diagnostic Errors at aLarge Tertiary Academic Center
Vladimir Ivanovic et al.
Acad Radiol 2022 (in press)

“There was a significant difference between mean volume of interpreted studies on shifts when an error was made compared with shifts in which no error was documented (46.58 (SD=22.37) vs 34.09 (SD=18.60), p<0.00001); and between shifts when perceptual error was made compared with shifts when interpretive errors were made (49.50 (SD=21.9) vs 43.26 (SD=21.75), p=0.0094). 59.6% of errors occurred in the emergency/inpatient setting, 84% were perceptual and 91.1% clinically significant.”
Impact of Shift Volume on Neuroradiology Diagnostic Errors at aLarge Tertiary Academic Center
Vladimir Ivanovic et al.
Acad Radiol 2022 (in press)

“Our data suggests that a workflowadjustment aiming at limiting the number of studies pershift below a critical threshold might be beneficial in reducing error rate. Based on the findings of this study, we are considering instituting a ceiling of around 40 studies per day within our Neuroradiology Division once we are able to be fully staffed. Having to interpret CT/MRI exams in excess of the proposed institution-specific ceiling in a single shift may result in worsened patient and institutional outcomes based on the above published data.”
Impact of Shift Volume on Neuroradiology Diagnostic Errors at aLarge Tertiary Academic Center
Vladimir Ivanovic et al.
Acad Radiol 2022 (in press)

“A long-recognized method to reduce error in interpretation is to have “ films interpreted independently by two readers”. Double reading is not practiced consistently in the United States because it is time-consuming and the second read is not reimbursed. Because of the time commitment and lack of financial compensation, double reading should be reserved for complex cases in which a second opinion will provide a substantial benefit.”
Interpretive Error in Radiology 
Waite S et al.
AJR 2017; 208:739–749

“The practice of reinterpreting imaging ex- aminations performed at outside institutions is becoming commonplace at academic centers because of a relatively high rate of discrepancies affecting patient care. Error rates as high as 41% have been reported during the reinterpretation of outside CT and MRI examinations in patients with head and neck cancer at an academic center.” 
Heuristics and Cognitive Error in Medical Imaging 
Itri JN, Patel SH
AJR 2018; 210:1097–1105

Purpose To determine the rate and nature of significant discordances between community and subspecialist emergency radiologists’ interpretations of cross-sectional exams performed on patients transferred to our trauma center.
Conclusion There is frequent discordance between community and emergency radiologists’ interpretations of CT and MRI exams, leading to a change in transferred patient management. Thus, trauma center radiologists provide added value over- reading these patients’ exams. It is difficult to predict which patients or exams will contain discordances, justifying routine overreading of all such exams.
Transfer patient imaging: discordances between community and subspecialist emergency radiologists 
Michael G. Flowers et al.
Emergency Radiology (2022) 29:395–401

“Radiologists use visual detection, pattern recognition, memory, and cognitive reasoning to synthesize final interpretations of radiologic studies. This synthesis is performed in an environment in which there are numerous extrinsic distractors, increasing workloads and fatigue. Given the ultimately human task of perception, some degree of error is likely inevitable even with experienced observers. However, an understanding of the causes of interpretive errors can help in the development of tools to mitigate errors and improve patient safety.”
Interpretive Error in Radiology 
Waite S et al.
AJR 2017; 208:739–749

“Errors in radiology are broadly classified into perceptual errors and interpretive errors. Perceptual errors account for 60–80% of errors and occur when an abnormality is present on a diagnostic image but not seen by the interpreting radiologist Interpretive errors constitute the remaining 20–40% of errors and occur when an abnormality is identified on an image but its meaning or importance is incorrectly interpreted.” 
Heuristics and Cognitive Error in Medical Imaging 
Itri JN, Patel SH
AJR 2018; 210:1097–1105

“ At our busy academic institution, we have noticed repeated examples of certain misdiagnosis, even by experienced abdominal imagers, both in our own department and at outside institutions. This is likely related to many factors. Discussed here are a variety of common diagnostic errors on body CT examinations.” 
MDCT of the Abdomen: Common Misdiagnosis at a Busy Academic Center
Horton KM, Johnson PT, Fishman EK
AJR 2010; 194:660-667

“ Reviewing the full-FOV from lumbar spine CT examinations will result in the detection of a small number of substantial extraspinal pathologic findings in addition to many benign incidental findings.”
Extraspinal Findings at Lumbar Spine CT Examinations: Prevalence and Clinical Importance
Lee SY et al.
Radiology 2012; 263:502-509

“ Extraspinal findings were present in 40.5% of adult outpatients undergoing lumbar spine CT examinations for low back pain and/or radiculopathy, most (62.3%) of whom had findings classified as benign and not requiring further work-up.”
Spine CT Examinations: Prevalence and Clinical Importance
Lee SY et al.
Radiology 2012; 263:502-509

“ The full field of view (FOV) abdominal images were required to best visualize extraspinal abnormalities in 79.4% of cases.”
Spine CT Examinations: Prevalence and Clinical Importance
Lee SY et al.
Radiology 2012; 263:502-509

“ Substantial extraspinal pathologic findings, consisting of an early stage renal cell carcinoma and transitional cell carcinoma, chronic lymphocytic leukemia, sarcoidosis, and 13 abdominal aortic aneurysms, were present in 4.3% of our cohort of 400 patients.”
Spine CT Examinations: Prevalence and Clinical Importance
Lee SY et al.
Radiology 2012; 263:502-509

Do you need to look at the topogram (scoutview) on all cases of CT scanning?