Joel P. Thompson MD, Presenter: Nothing to Disclose

Steven Lee MD, Abstract Co-Author: Nothing to Disclose

Akshya Gupta MD, Abstract Co-Author: Nothing to Disclose

Susan K. Hobbs MD, PhD, Abstract Co-Author: Nothing to Disclose

John Gilbert Strang MD, Abstract Co-Author: Nothing to Disclose

Thomas H. Foster PhD, Abstract Co-Author: Nothing to Disclose

To quantify the risks and benefits of changing CT protocol in the ED/trauma setting to include an arterial phase CT of the abdomen.  

Several recent studies have demonstrated increased sensitivity for identifying contained splenic vascular injury (ie pseudoaneurysm and arteriovenous fistula formation) in trauma patients by the addition of arterial-phase CT abdominal imaging. However, the overall risk-benefit ratio is not known. Using published data, we quantified the number of previously undiagnosed cases of contained splenic vascular injury in trauma patients age 15 and older, as well as the number of patients for whom management would change and the number of new cancer cases induced by the increased radiation dose. During sensitivity analysis, supplemental data from a level 1 trauma center was used to help identify patient subgroups with a more favorable risk-benefit ratio.

The number needed to scan to identify one new case of contained vascular injury was 182, to change management in one patient was 255, and to induce one new cancer was 3,584. Increased dose length product (DLP) resulted in higher cancer induction risk, but this risk was relatively small and did not result in more cancer cases caused than new vascular injury cases detected over a range of normal DLP values. Analysis using the age distribution of trauma patients at our institution and an age-dependent cancer induction rate did not significantly change results. Pending results include additional analysis utilizing data from a level 1 trauma center, including stratification by gender, mechanism of injury (blunt versus penetrating) and severity of injury (level 1 trauma, level 2 trauma, or overall population).    

The addition of an arterial phase CT abdomen to a trauma protocol for the assessment of contained splenic vascular injury has a favorable risk-benefit ratio across a range of typical DLP values. 

The addition of an arterial phase CT abdomen to a trauma protocol for the assessment of contained splenic vascular injury has a favorable risk-benefit ratio across a range of typical DLP values. 

Thompson, J, Lee, S, Gupta, A, Hobbs, S, Strang, J, Foster, T, A Risk-Benefit Analysis of Adding an Arterial-Phase CT Abdomen When Evaluating for Splenic Trauma.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14009427.html