"Errors are simply unavoidable for both experienced radiologists and radiology trainees," said Ashley Etchison, MD, second year diagnostic radiology resident at Baylor College of Medicine (BCM).
Dr. Etchison described two types of errors radiologists make: cognitive and perceptual. "Perceptual errors account for 60% to 80% of trainee errors and are often referred to as 'eye tests,' meaning one simply did not look at a portion of an imaging study and missed a finding."
Conversely, she noted, cognitive errors occur when a trainee identifies a critical finding but misinterprets its significance.
Her education exhibit presented at RSNA 2020 provides a thorough review of on-call diagnostic errors, including a robust selection of neuroradiology, thoracic, abdominal and musculoskeletal cases identified as common pitfalls in diagnosis.
One example focuses on a false report of an acute, right occipital subdural hematoma. The trainee identified a hyperdense crescentic structure along the right occipital convexity and did not recognize the structure as a normal transverse sinus.
This represents a cognitive error that, according to Dr. Etchison, could potentially have been avoided if the trainee had developed more familiarity with normal anatomy and related variants.
In addition, to avoid cognitive errors she recommended considering the most likely diagnosis in the current clinical setting and applying the patient's clinical history and examination findings. Dr. Etchison also warned against being confused by mimickers that can lead to misdiagnosis. In the example of the false positive subdural hematoma, structures such as venous sinuses, cortical veins and meningioma may be misleading to inexperienced trainees.
Search Patterns Aid Perception
Another study presented in the exhibit demonstrated an example of a perceptual error. The trainee identified bilateral patchy opacities on the patient's lung but overlooked cavitary nodules that were later revealed as findings consistent with tuberculosis (TB).
To avoid perceptual errors, Dr. Etchison recommended applying a search pattern and methodically examining the study in a carefully prescribed way.
"Consistent utilization of search patterns reduces perceptual errors. If a radiologist follows a particular pattern every time she or he interprets an exam, it is less likely that a particular anatomical region (and a potential finding) will be overlooked," she said.
According to Dr. Etchison, radiology educators can help trainees overcome "blind spots" by building them into search patterns so they are not overlooked. "A resident who consistently misses pleural effusions on abdominal CTs can add a review of the lung bases to her or his search patterns," she said.
Other strategies for overcoming perceptual errors include knowing common locations for disease processes, using all available studies and reformatted images as needed and adjusting the window to increase contrast for soft-tissue pathogens.
Several studies in the exhibit, including the missed TB diagnosis, demonstrate the value of additional imaging and the use of multiple planes, an approach that Dr. Etchison said is imperative for accurate interpretation of diagnostic imaging.
"Radiology trainees must learn which planes assist with identifying anatomical features and pathological findings."
Dr. Etchison noted that in her residency program at BCM, the most respected educators recognize common diagnostic challenges faced by trainees and provide targeted teaching during readout sessions.
"In this way, educators mitigate common cognitive and perceptual errors early in a resident's training so that mistakes are not perpetuated."
For More Information
View the RSNA 2020 session Avoiding Common On-Call Errors: A Guided Tutorial for Radiology Residents — ER101-ED-X at RSNA2020.RSNA.org.