Elliot K. Fishman M.D.
Johns Hopkins Hospital

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• 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

“Missed findings rather than misinterpretations of detected abnormalities were the most common reason for abdominopelvic CT report addenda. Awareness of the most common misses by anatomic location may help guide quality assurance initiatives. A wide variety of contributing factors were identified. Informatics and workflow optimization may be warranted to facilitate radiologists’ access to all available patient-related data, as well as communication with other physicians, and thereby help reduce diagnostic errors.” 
Diagnostic errors in abdominopelvic CT interpretation: characterization based on report addenda 
Andrew B. Rosenkrantz, Neil K. Bansal 
Abdom Radiol (2016) 41:1793–1799

“709 addenda describing 785 diagnostic errors were identified, representing approximately 0.5% of searched reports. 84.1% were a new finding, 5.1% an upgrade in severity of an originally reported finding, 3.9% a downgrade in severity, and 6.9% other modification.” 
Diagnostic errors in abdominopelvic CT interpretation: characterization based on report addenda 
Andrew B. Rosenkrantz, Neil K. Bansal 
Abdom Radiol (2016) 41:1793–1799

“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.

“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

“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

”Radiological errors can be classified according to the reporting process as pre-reporting, reporting or post- reporting errors. Pre-reporting errors consist of tech- nical issues and procedure-related problems, whereas post-reporting errors are mainly caused by poor communication between radiologists and clinicians. Reporting errors are directly related to radiologists and can be categorized into two parts. "Perceptual errors" are more common and related to the fact that the present finding is not noticed, while "interpretative errors" are influenced by cognitive biases that can contribute to false reasoning.”
Errors, discrepancies and underlying biasin radiology with case examples: a pictorial review
Omer Onder et al. 
Insights Imaging (2021) 12:51 https://doi.org/10.1186/s13244-021-00986-8

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

“Allowing for a subjective definition of clinical significance as determined by radiologists, and understanding that our patient population is highly selective, we have identified a relatively frequent rate of discordance between community and subspecialty-trained emergency radiologists when it comes to interpreting cross-sectional exams of trauma patients. Slightly more errors are made on MRI than CT, and while the most common errors involved the head, neck, and spine, errors were distributed throughout the body. Errors were made by a wide number of community radiologists, as opposed to a small number of outliers. These findings suggest that trauma center radiologists provide added value overreading 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

“ 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

“ For each diagnostic error, we explore the reasons for the misdiagnosis and provide experience based advise to avoid these mistakes.” 
MDCT of the Abdomen: Common Misdiagnosis at a Busy Academic Center
Horton KM, Johnson PT, Fishman EK
AJR 2010; 194:660-667

Purpose: To determine if administering IV contrast for CT abdomen and pelvis improves detection of urgent and clinically important non-urgent pathology in patients with urgent clinical symptoms compared to patients not receiving IV contrast, and in turn to determine whether repeat CT exams on the same patient within 72 h were of low diagnostic benefit if the first CT was performed with IV contrast. 
Conclusion: In the absence of contraindications, encouraging urgent care physicians to preferentially order IV contrast-enhanced CT AP examinations in adherence with ACR appropriateness criteria may increase detection of urgent pathology and avoid short- term repeat CT. 
Effect of intravenous contrast for CT abdomen and pelvis on detection of urgent and non-urgent pathology:can repeat CT within 72 hours be avoided? 
Lamoureux C et al.
Emergency Radiology (2019) 26:601–608

“In our study of patients with duplicate CT abdomen and pelvis within 72 h, the majority of CT exams repeated within the first 6 h were performed first without IV contrast followed by a second CT with IV contrast. Urgent findings were more likely to be detected on the first CT when IV contrast was used. While this may be influenced by patient selection, it could speak to the importance of IV contrast usage in making a rapid definitive ED diagnosis. Furthermore, urgent findings were more likely to be better characterized on the second CT when the first CT was performed without IV contrast followed by IV contrast on the second CT. Our study suggests that in patients with acute abdominal and pelvic symptoms for whom CT abdomen and pelvis is clinically warranted, IV contrast administration should be strongly considered.”
Effect of intravenous contrast for CT abdomen and pelvis on detection of urgent and non-urgent pathology: can repeat CT within 72 hours be avoided? 
Lamoureux C et al.
Emergency Radiology (2019) 26:601–608

“The results of this study advance our understanding of how administration of intravenous contrast administration for CT of the abdomen and pelvis influence detection of urgent and non-urgent clinically important pathology in the urgent setting. To reduce potentially medically unnecessary redundant imaging within a short timeframe, this information may be useful for optimization of CT examination protocols.”
Effect of intravenous contrast for CT abdomen and pelvis on detection of urgent and non-urgent pathology: can repeat CT within 72 hours be avoided? 
Lamoureux C et al.
Emergency Radiology (2019) 26:601–608

“Our Emergency physicians do not see that oral contrast administration for CT hampers operational efficiency; in fact, they have expressed gratitude to our department for care in diagnosis. They have stated that delays in patient turnaround are more frequently related to overall demand on the scanner and not to the oral contrast consumption period. They are all acutely aware of the serious consequences of missed or incorrect diagnoses (either leading to inappropriate hospital admission or discharge), and will always choose good medical care over time slashing, corner cutting methods that impress the dashboard monitors perhaps at the expense of excellence in patient care.”
Oral contrast utilization for abdominal/pelvic CT scanning in today’s emergency room setting
Megibow A.J. 
Abdom Radiol (2017) 42: 781. doi:10.1007/s00261-016-0941-2

“In summary, the Radiology department at NYU-Langone Medical Center has, through dialogue with our Emergency Medicine section, reaffirmed the benefits of oral contrast utilization for CT scanning of ED patients. We have found that stocking the oral contrast in the ED and allowing a 45-min period for oral contrast administration coordinated with obtaining clinical and laboratory information facilitate radiologic diagnosis with a high level of confidence and accuracy. As stated by JRD Tata, it is insistence on relentless attention to detail and insistence on highest standards of quality and performance that are the keys to productivity and efficiency, most certainly not through cutting corners.”
Oral contrast utilization for abdominal/pelvic CT scanning in today’s emergency room setting
Megibow A.J. 
Abdom Radiol (2017) 42: 781. doi:10.1007/s00261-016-0941-2

CONCLUSION. As radiologists, we owe it to our patients to drive the appropriate use of positive oral contrast material. At the very least, we should not allow non-radiologists to restrict its use solely on the basis of throughput concerns; rather, we should allow considerations of image quality and diagnostic confidence to enter into the decision process. Based on differences in prior training and practice patterns, some radiologists will prefer to limit the use of positive oral contrast material more than others. However, for those who believe (as I do) that it can genuinely increase diagnostic confidence and can sometimes (rather unpredictably) make a major impact on diagnosis, it behooves us to keep fighting for its use. 
Positive Oral Contrast Material for Abdominal CT: Current Clinical Indications and Areas of Controversy 
Perry J. Pickhardt 
AJR 2020; 215:1–10

“A disturbing recent trend, however, is the increasing decision to forego positive oral contrast material largely (or solely) for increased patient throughput, typically driven by non-radiologists such as emergency department (ED) physicians, surgeons, and even health system administrators. As radiologists, we need to ensure that such financially driven nonmedical justifications are in the best interest of our patients.” 
Positive Oral Contrast Material for Abdominal CT: Current Clinical Indications and Areas of Controversy 
Perry J. Pickhardt 
AJR 2020; 215:1–10