Helical computed tomographic angiography: an excellent screening test for blunt cerebrovascular injury

Blunt cerebrovascular injury (BCVI) carries a high morbidity and mortality, especially when diagnosis is delayed. Recent studies have shown that increased recognition of these injuries is achieved with prompt screening, allowing for early treatment and better outcome. Controversy still exists, however, on the best screening test. This study was used to evaluate the role of helical computed tomographic angiography (CTA) of the carotid and vertebral arteries in the early screening of BCVI.

All patients deemed at risk for BCVI underwent CTA within 24 hours of admission. Patients with a negative CTA test underwent no further radiologic evaluation of the cerebral vasculature. Those patients with positive or equivocal CTA results underwent four-vessel cerebral arteriography as a confirmatory test. Data were collected on the radiologic interpretation of all studies and patient clinical course.

Four hundred eighty-six patients fulfilled the criteria for screening and underwent CTA. Nineteen patients were diagnosed with 25 BCVIs during the period of study. There were 7 carotid injuries and 18 vertebral injuries. Eighteen of 19 patients with BCVI were screened with CTA. Seventeen patients were asymptomatic at the time of screening. Results of CTA for BCVI were as follows: sensitivity, 100%; specificity, 94.0%; prevalence (screened patients), 3.7%; positive predictive value, 37.5%; and negative predictive value, 100%. Except for one patient in whom the CTA was clearly misinterpreted by the radiologist, no patient with a negative CTA examination was subsequently found to have a missed injury.

CTA is an excellent test with which to screen for BCVI.