Diagnostic Performance and Reliability of 4-Point CT Brain Angiography and Precentral Gyrus Cortical Thickness in Brain Death Assessment

Background: Brain death (BD) diagnosis is ethically and clinically crucial, especially in potential organ donor cases where rapid and accurate determination is vital. Although computed tomography angiography (CTA) provides high specificity, its variable sensitivity may lead to false negatives, necessitating complementary diagnostic methods.Purpose: This study aimed to evaluate the diagnostic performance and observer reliability of precentral gyrus cortical thickness measurements in BD diagnosis and to compare them with the 4-point CTA method.Materials and Methods: This retrospective study included 42 clinically confirmed BD patients and 144 healthy controls. Brain CT and CTA images were analyzed by two independent, blinded radiologists at two separate time points. Precentral gyrus cortical thickness was measured in both hemispheres, and 4-point CTA scoring was performed. ROC curve analysis determined cut-off values, sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV). Intra- and interobserver reliability was evaluated using ICC, Cohen’s Kappa, and Bland–Altman analyses.Results: The 4-point CTA showed 97% accuracy, 88% sensitivity, and 100% specificity. Precentral gyrus cortical thickness achieved approximately 90% sensitivity, specificity, and accuracy. Observer agreement was excellent (ICC=0.988–0.999; p