CT scans do not appear to be necessary for adults presenting to the ED with mild head injuries (MHIs). In a retrospective study of patients with MHI who underwent CT scans, pathological acute findings on CT scans were found in only 2.18% of participants. The rate of pathological acute findings jumped from 0.66% among those aged 65 to 79 to 3.33% among those older than 80 and were relatively higher among all antiplatelet users (3.72%).

Abstract: American Journal of Emergency Medicine, January 2013.