CT angiography as a confirmatory test in diagnosis of brain death: comparison between three scoring systems

Abstract

PURPOSEComputed tomography (CT) angiography emerges as a vi-able alternative technique for confirmation of brain death. However, evaluation criteria are not well established for demonstration of cerebral circulatory arrest. This retrospec-tive study aimed to evaluate CT angiography scoring systems in diagnosis of brain death, review the literature, and com-pare interobserver agreement between different scales for the diagnosis of brain death.METHODSCT angiography examinations of 25 patients with a clinical diagnosis of brain death were reevaluated according to 10-, 7-, and 4-point scales. Exams were performed with a 64-slice CT scanner including unenhanced, arterial (20 s) and venous phase (60 s) scans. Subtraction images of both phases were obtained. Interobserver agreement was evaluated for the as-sessment of vessel opacification and diagnosis of brain death.RESULTSAccording to 10-, 7-, and 4-point scales; 13, 16, and 22 of 25 patients had full score, respectively. Using the clinical exam as the reference standard, sensitivities obtained for 10-, 7-, and 4-point scales were 52%, 64%, and 88%, respectively. Percent agreement between readers was 100% for 10- and 7-point scales and 88% for 4-point scale. Percent agreement for opacification of scale vessels was equally high for all three scales (93.6%, 93.7%, 91% for 10-, 7-, and 4-point scales, respectively).CONCLUSIONThe 4-point scale appears to be more sensitive than the 10- and 7-point scales in CT angiography evaluation for brain death. Interobserver agreement is high for all three scales when subtraction images are used