Study objectives: To determine the concordance of emergency physicians and radiologists in interpreting cranial computed tomography (CT) scans. The study also sought to determine the clinical significance of misinterpretations of cranial CT scans by emergency physicians.
Design: Prospective cohort study.
Setting: A county hospital emergency medicine residency program.
Participants: Five hundred fifty-five patients undergoing CT scanning during emergency department evaluation.
Results: Forty-nine percent (272) of the indications for CT scanning were for trauma, 14.2% (79) were for cerebrovascular accident, 25.1% (139) were for headache, 15.1% (84) were for seizure, and 13.7% (76) were for miscellaneous reasons. The radiologists interpreted 46.1% (256) of the CT scans as abnormal. The most frequent abnormalities were scalp hematoma, 15.2% (39); infarction, 14.1% (36); calcification, 6.3% (16); contusion, 6.3% (16); parenchymal hemorrhage, 5.1% (13); and mass, 5.1% (13). Nonconcordance between radiologists and emergency physicians was found in 38.7% (206) of the cases. Potentially clinically significant misinterpretations were found in 24.1% (131) of the total sample. These misinterpretations included 62 missed major findings (11.4% of total sample): 25 new infarcts, 10 mass lesions, 8 cases of cerebral edema, 8 parenchymal hemorrhages, 5 contusions, 4 subarachnoid hemorrhages, 1 epidural hematoma, and 1 subdural hematoma. However, on chart review, only three patients (0.6%) were found to have been managed inappropriately, and none had an adverse outcome.
Conclusion: The misinterpretation rate of cranial CT scans by emergency physicians is of potential clinical concern. However, clinical mismanagement is rare. We recommend that more formal education in CT interpretation be included in residency training and continuing medical education programs for emergency physicians.