Thoracic computed tomography in victims of blunt trauma: changes in utilization after the introduction of helical technology

Purpose: In blunt trauma, CT of the thorax is often performed because of the limitations of plain film chest radiography in accurately depicting injuries to the thoracic aorta. The advent of helical CT has allowed the entire chest to be imaged more expeditiously. We will evaluate the extent to which this ability to rapidly obtain additional images of the thorax has increased the utilization of chest CT in blunt trauma. Methods: The radiologic records of all victims of blunt trauma who underwent total body CT (TBCT), which included abdomen, pelvis, and chest images, in the 10 months before and 10 months after our institution acquired helical CT (HCT), were retrospectively evaluated. Results: In the 10 months before we obtained HCT, 520 conventional CT of the abdomen and pelvis were completed, of which only 11 (2.1 %) included images of the full thorax. After HCT was instituted, 684 abdomen and pelvis CT were performed, of which 59 (8.6 %) were ordered with the entire chest. Of the 11 conventional TBCT, 6 (55 %) showed findings in the chest; in 2 of these cases (18 %) the abnormalities were confined exclusively to the thorax. Similarly, of the 59 helical TBCT, 31 (53 %) depicted traumatic abnormalities in the thorax, and in 23 of these cases (39 %) injuries were only within the chest. In 4 of the latter the injuries were mediastinal hematomas, 1 of which (25 %) was confirmed angiographically to represent an aortic laceration. Conclusion: The speed and ease with which additional images can be obtained by HCT has greatly increased utilization of cross-sectional imaging of the thorax after blunt trauma (approximately four-fold). Over half of these depict traumatic injuries.