The increasing use of chest computed tomography for trauma: is it being overutilized?

Chest computerized tomography (CCT) has gained popularity in trauma evaluation, but it is expensive, increases exposure to radiation, and leads to findings of debatable clinical significance. The objective of this study was to determine the change in usage of CCT over time and the number of injuries missed on plain chest radiograph (CXR) with normal findings that required therapy.

Data on all patients evaluated with a screening CXR during a 7-year period were extracted from a Level I center trauma registry. The incidence of CCT utilization during the duration of the study was identified. Patients who had CCT done after the initial CXR were analyzed separately for the presence of occult injuries. The association of these findings with demographic and injury data were examined.

There were 2,326 CCT performed, and 1,873 (80.5%) of them were after negative CXRs. The percentage of patients studied with CCT increased incrementally from 2.7% to 28.7% for blunt and from 0.4% to 2.9% for penetrating injury. The identification of occult pneumothorax, hemothorax, rib fractures, and lung contusions significantly increased during the study period with the increased frequency of CCT use. There were 102 occult pneumothoraces and/or hemothoraces identified, but only 12 patients underwent tube thoracostomy during the 7-year period. There were 43 patients with blunt aortic injury (BAI) and 6 (13.9%) of these patients had normal CXR findings. There was no trend in increased BAI diagnosed during the study period, although the utilization of CCT was increased.

There has been a 10-fold increase in use of CCT for trauma evaluation. Although occult findings increased, the number of patients who needed treatment was small. The excess utilization of CCT after negative CXR needs continued refinement to identify the small number of potentially lethal injuries while reducing the number of trivial findings.