Arterial injuries after penetrating brain injury in civilians: risk factors on admission head computed tomography

OBJECT The object of this study was to determine the specific CT findings of the injury profile in penetrating brain injury (PBI) that are risk factors related to intracranial arterial injuries. METHODS The authors retrospectively evaluated admission head CTs and accompanying digital subtraction angiography (DSA) studies from patients with penetrating trauma to the head in the period between January 2005 and December 2012. Two authors reviewed the CT images to determine the presence or absence of 30 injury profile variables and quantified selected variables. The CT characteristics in patients with and without arterial injuries were compared using univariate analysis, multivariate analysis, and receiver operating characteristic (ROC) curve analysis to determine the respective risk factors, independent predictors, and optimal threshold values for the continuous variables. RESULTS Fifty:five patients were eligible for study inclusion. The risk factors for an intracranial arterial injury on univariate analysis were an entry wound over the frontobasal-temporal regions, a bihemispheric wound trajectory, a wound trajectory in proximity to the circle of Willis (COW), a subarachnoid hemorrhage (SAH), a higher SAH score, an intraventricular hemorrhage (IVH), and a higher IVH score. A trajectory in proximity to the COW was the best predictor of injury (OR 6.8 and p = 0.005 for all penetrating brain injuries [PBIs]; OR 13.3 and p = 0.001 for gunshot wounds [GSWs]). Significant quantitative variables were higher SAH and IVH scores. An SAH score of 3 (area under the ROC curve [AUC] for all PBIs 0.72; AUC for GSWs 0.71) and an IVH score of 3 (AUC for all PBIs 0.65; AUC for GSWs 0.65) could be used as threshold values to suggest an arterial injury. CONCLUSIONS The risk factors identified may help radiologists suggest the possibility of arterial injury and prioritize neurointerventional consultation and potential DSA studies.