The purpose of this study was to evaluate the effectiveness and efficiency of a chest radiograph-based detection algorithm for aortic injury and to determine if a previously developed clinical prediction rule would improve imaging efficiency. A 3-year single institution retrospective case-control study with 25 cases of aortic injury and 181 controls was conducted. The detection algorithm correctly identified 96% of all cases of aortic injury, and a definitive diagnosis was established within 6h for 80% of the patients. However, its efficiency was marginal, with only one in 400 chest X-rays leading to a positive diagnosis. The previously developed clinical prediction rule was not able to stratify patients into a clinically useful range of injury probability, and thus the prediction rule cannot be used to improve the efficiency of the existing detection algorithm.