Recommendations for additional imaging on emergency department CT examinations: Comparison of emergency- and organ-based subspecialty radiologists

Purpose: Past studies have identified a high frequency of recommendations for additional imaging (RAI) for computed tomography (CT) studies performed in an emergency department (ED), thereby potentially contributing to increased imaging utilization and costs. The purpose of this study was to compare rates of RAI within the ED setting between ED-based and organ-based subspecialty radiologists. Methods: We identified 600 ED CT studies, comprising 200 head, chest, and abdominal CT studies, split equally between cases reviewed by ED-based and organ-based radiologists. Frequency of RAI for the three examinations was compared between these subspecialty groups. Results: Frequencies of RAI were 21.5 %, 13.5 %, and 5.5 % for CT examinations of the chest, abdomen, and brain, respectively. There was a significantly higher frequency of RAI for chest CT studies interpreted by chest radiologists than by ED radiologists (28.0 % vs. 15.0 %, respectively, p = 0.036), largely due to a higher rate of RAI for incidentally detected lung nodules and masses as well as other pulmonary parenchymal abnormalities by chest radiologists. There was no significant difference in RAI on brain or abdominal CT studies between the two groups (p = 0.426-1.0). However, on abdominal studies, only ED-based radiologists provided RAI for abnormalities of the bowel or uterus, while only organ-based radiologists provided RAI for pancreatic abnormalities. Only 25.6 % of RAI were subsequently performed at our institution. Conclusion: For chest CT studies performed at the authors' institution, differences in management of incidental pulmonary nodules contributed to a significantly higher frequency of RAI by chest radiologists than by ED-based radiologists. Further investigation of the impact of these differences on cost and patient outcomes is warranted.