pmSAH May Have Arterial Etiology

Background: Perimesencephalic subarachnoid hemorrhage (pmSAH) is a distinct subtype of SAH with hemorrhage centered in the perimesencephalic cisterns without extension into the interhemispheric and sylvian fissure; the dominant theory of hemorrhage source is venous etiology. pmSAH has a good prognosis, with a low risk of rebleeding or vasospasm. Application of high-resolution cone-beam CT (CBCT) technique could help identify the source of the bleeding. Objective: To test the hypothesis that high-resolution CBCT during angiography could better identify pmSAH etiology. Design: Single-center retrospective analysis of a prospectively maintained institutional database of patients with SAH from 2023 to 2024. Methods: Patients with pmSAH who underwent catheter angiography with CBCT data were included. The contrast protocol on both Siemens Icono and Artis Q machines varied to obtain a homogenous opacification of the vertebrobasilar system without inflow from the other vertebral artery throug more...