Trauma and Emergency Room Imaging / L'imagerie des urgences et des traumatismes Incidental Findings on Bedside Ultrasonography: Detection Rate and Accuracy of Resident-Performed Examinations in the Acute Setting

Background: Bedside ultrasonography has become a valuable tool in the emergent care setting for triage and rapid evaluation of patients who are acutely ill. Given the cross-sectional nature of ultrasound technology, incidental findings are frequently encountered during imaging. These can impact clinical management and can pose a diagnostic dilemma for emergency medicine (EM) physicians and EM residents. Purpose: Our retrospective study was designed to evaluate the prevalence and detection rate of incidental findings on bedside ultrasound examinations performed by EM residents. We also sought to identify types of incidental findings encountered and the diagnostic accuracy of those findings. Materials and Methods: Board-certified radiologists retrospectively reviewed bedside ultrasonography examinations performed and interpreted by EM residents at a large urban academic hospital. Our sample included patients who presented with traumatic and nontraumatic symptoms in the acute setting. Findings were defined as incidental only if they were previously unknown and not related to a patients presenting symptoms. The results were corroborated with electronic medical records and additional pertinent imaging when available. Results: Of 196 examinations analysed, EM residents identified incidental findings on 26% of the studies, which mostly involved the renal and biliary system. Radiologist review detected incidental findings in 20.9% but was more accurate when supplemental imaging was available. EM residents detected incidental findings at rates similar to that published previously and had moderate interobserver agreement with radiologist review. Worrisome and indeterminate findings were confirmed by additional work-up and further imaging. Conclusion: Incidental findings are frequently encountered on bedside ultrasonography and have the potential to alter clinical management. Expertise in detection and knowledge of the presence and spectrum of these incidental findings is essential for appropriate triage, patient management, and follow-up.