Single-Pass Split-Bolus Whole-Body Contrast-Enhanced Computed Tomography Protocol for Trauma Patients

Abstract

Objective : We sought to improve the aortic enhancement to allow proper assessment and detection of vascular injury in whole-body contrast-enhanced computed tomography (WBCT) of trauma patients without increasing the radiation dose by using a single-pass combined arterial and venous phase split-bolus protocol, instead of a conventional venous phase single-bolus protocol. Methods: A retrospective study assessed consecutive trauma patients who underwent WBCT in two 6-month periods, one in which patients underwent the single-bolus protocol and one in which they underwent the split-bolus protocol. In the split-bolus group, 80 mL iohexol (300 mgI/mL) was injected after the plain CT scan and additional 40 mL iohexol was injected 60 s later. Post-contrast CT images were acquired at 90 s after starting the first contrast injection. Enhancement of the aorta, liver, spleen and kidneys and dose-length product (DLP) of WBCT were measured and compared between patients in the two scan protocols. Results: A total of 95 patients were included. There was statistically significant improvement of the enhancement of the ascending aorta, descending thoracic aorta (177±36 vs. 249±63 HU, p < 0.001), infrarenal aorta, spleen (123±16 vs. 146±21 HU, p < 0.001), right renal cortex (194±34 vs. 227±42 HU, p < 0.001) and left renal cortex (193±37 vs. 228±40 HU, p < 0.001) in the split-bolus group. In the split-bolus group, the aortic enhancement was >200 HU, which was considered to be sufficient for proper assessment and detection of vascular injury in literature. There was no statistically significant difference in the DLP (3406±1076 vs. 3194±1261 mGycm, p = 0.152), which is an effective dose of 64.7 mSv in the single-bolus group and 60.7 mSv in the split-bolus group. Conclusion:The split-bolus protocol increased the aortic enhancement to allow proper assessment and detection of vascular injury of trauma patients without increasing the radiation dose. Our study used the lowest possible contrast dose to achieve diagnostic images among different studies.