Sixteen-slice multi-detector computed tomographic angiography improves the accuracy of screening for blunt cerebrovascular injury

Abstract

Background: Blunt cerebrovascular injuries (BCVI) are rare but potentially devastating injuries, particularly if the diagnosis is delayed. Only four-vessel cerebral angiography (FVCA) has been shown to be adequately sensitive and specific as a screening tool for BCVI but is resource-intensive and invasive. Computed tomography (CT) angiography has emerged as a possible alternative, but its accuracy has been poor, particularly for low-grade injuries. Recent advances in CT technology, particularly the use of a multi-detector array for image acquisition should improve the accuracy of this technique. This study is the first reported experience of the role of the 16-slice multi- detector CT scanner in screening for BCVI.

Methods: From January 2, 2003 to October 31, 2004, all patients who met predefined screening criteria were screened for blunt injury to the carotid (BCI) and vertebral (BVI) arteries with a 16-slice multi-detector CT scanner with angiographic reconstruction (CTA). If CTA was positive or equivocal for BCVI, FVCA was performed as a confirmatory test. If CTA was negative, no further diagnostic studies were performed.

Results: There were 435 patients who met criteria and were screened with CTA. Of these, 25 injuries were identified in 24 patients for an incidence of BCVI of 1.2% (24/2023) among all blunt admissions (BTA) and 5.5% (24/435) among screened patients (SP). This was increased compared with the four-slice era (0.38% BTA, 2.4% SP, p<0.01). No patient with a negative CTA was subsequently identified as having, or developed neurologic symptoms attributable to a missed BCVI.

Conclusion: Sixteen-slice multi-detector CT angiography is an excellent tool to screen for BCVI and detects all clinically significant injuries. The detected incidence of BCVI increased more than threefold with the 16-slice scanner when compared with the four-slice scanner. This demonstrates a clear technological improvement in our ability to screen for these injuries.