Routine pan–computed tomography (CT, including of the head, neck, chest, abdomen/pelvis) has been advocated for evaluation of patients with blunt trauma based on the belief that early detection of clinically occult injuries will improve outcomes. We sought to determine whether selective imaging could decrease scan use without missing clinically important injuries.

This was a prospective observational study of 701 patients with blunt trauma at an academic trauma center. Before scanning, the most senior emergency physician and trauma surgeon independently indicated which components of pan-CT were necessary. We calculated the proportion of scans deemed unnecessary that: (a) were abnormal and resulted in a pre-defined critical action or (b) were abnormal.

Pan-CT was performed in 600 of the patients; the remaining 101 underwent limited scanning. One or both physicians indicated a willingness to omit 35% of the individual scans. An abnormality was present in 18% of scans, including 22% of desired scans and 10% of undesired scans. Among the 95 patients who had one of the 102 undesired scans with abnormal results, 3 underwent a predefined critical action. There is disagreement among the authors about the clinical significance of the abnormalities found on the 99 undesired scans that did not lead to a critical action.

Selective scanning could reduce the number of scans, missing some injuries but few critical ones. The clinical importance of injuries missed on undesired scans was subject to individual interpretation, which varied substantially among authors. This difference of opinion serves as a microcosm of the larger debate on appropriate use of expensive medical technologies.