A. Laser1, B. R. Bruns1,3, J. A. Kufera3,4, R. Tesoriero1,3, C. W. Sliker2,3, T. M. Scalea1,3, D. M. Stein1,3 1University Of Maryland,Department Of Surgery,Baltimore, MD, USA 2University Of Maryland,Department Of Diagnostic Radiology & Nuclear Medicine,Baltimore, MD, USA 3University Of Maryland,R Adams Cowley Shock Trauma Center,Baltimore, MD, USA 4National Study Center For Trauma & EMS,Baltimore, MD, USA
Introduction: Our Whole-body CT protocol (WBCT) used to image polytrauma patients consists of a non-contrast head CT followed by a MDCT [40- or 64- slice] that includes an IV contrast-enhanced scan from the face through the pelvis. WBCT is used to screen for blunt cerebrovascular injury (BCVI) during initial CT imaging of the poly-trauma patient, and allow for early initiation of therapy with the goal of avoiding stroke. WBCT has not been directly compared to CT angiography (CTA) of the neck as a screening tool for BCVI. We hypothesize that WBCT is a valid modality to diagnose BCVI when compared to neck CTA, thus screening polytrauma patients for BCVI and limiting the need for subsequent CTA.
Methods: Retrospective review of the trauma registry for all patients diagnosed with BCVI from June 2009 to June 2013 at our institution was performed. All injuries identified by grade on initial WBCT and grading was compared to neck CTA imaging performed within the first 72 hours. Sensitivity was calculated for WBCT using CTA as the reference standard. Proportions of agreement were also calculated between the grades of injury for each imaging modality.
Results: 319 injured vessels were identified in 226 patients. On initial WBCT 80 (25%) of the injuries were grade I, 75 (24%) grade II, 45 (14%) grade III, 41 (13%) grade IV, and 58 (18%) were classified as indeterminate: 27 vertebral and 31 carotid lesions. Twenty (6%) of the 319 injuries were not detected on WBCT but identified on subsequent CTA (9 grade I, 7 grade 2, 4 grade III); 6 vertebral and 14 carotid. For each vessel type and for all vessels combined, WBCT demonstrated sensitivity rates of over 90% to detect BCVI among the population of patients with at least one vessel injured.
There was concordant grading of injuries between WBCT and initial diagnostic CTA in 149 (47% of all injuries). Lower grade injures were more discordant than higher grades (58% vs. 26%, respectively; p <0.001). Grading was upgraded 11% of the time and downgraded 32%.
Conclusion: WBCT holds promise as a rapid screening test for BCVI in the polytrauma patient and to identify injuries in the early stage of the trauma evaluation, thus allowing more rapid initiation of treatment. In patients at high-risk for BCVI, we continue to recommend dedicated neck CTA for better characterization of the injury, regardless of WBCT findings.
