Impact of Skull Defects on the Role of CTA for Brain Death Confirmation

Comparison of CT images without contrast medium (A, D, and G) in the arterial (B, E, and H) and venous (C, F, and I) phases of CTA (MIP reformations in coronal plane) from 3 distinct patients with a brain death clinical diagnosis. In a patient with an intact skull (upper row, A–C), opacification was observed in the M1–M2 branches (broad arrows) in the arterial (B) and venous (C) phases and was more intense in the late phase. In a patient with craniotomy (middle row, D–F), one can appreciate the relative hyperattenuation of both M1 branches mimicking vascular opacification in noncontrast CT (arrowheads in D). Opacification was observed in both M2 branches (broad arrows in the arterial phase, E) and the right M3 branch in the venous phase (thin arrow in F), a phenomenon known as stasis filling. In a patient presenting with craniectomy (lower row, G–I), opacification was observed in both M2 branches (broad arrows in the arterial phase, H), the right M3 branch, and the left M4 branch in the venous phase (thin arrow in I) due stasis filling, a false-negative case of BD.