Preoperative evaluation of the microanatomy around an aneurysm is mandatory for safe clipping of a cerebral aneurysm. We assessed the usefulness of three-dimensional variable refocusing flip angle-turbo spin-echo (3D VRFA-TSE) in determining the microanatomy around aneurysms.
Between May 2015 and June 2017, 25 patients with 26 unruptured middle cerebral artery aneurysms were evaluated using MR T2-weighted imaging, 3D VRFA-TSE T2-weighted imaging, and cerebral angiography before surgery. All aneurysms were treated via neck clipping at our hospital. The high-intensity signal of the cerebrospinal fluid (CSF) was used as an indicator of the preserved CSF space without adhesion of an aneurysm to a surrounding structure. 3D VRFA-TSE T2-weighted imaging, conventional T2-weighted imaging, and cerebral angiography were used to assess the adhesion between the aneurysm and the artery. To assess the adhesion of the vein, we compared T2-weighted imaging findings to the intraoperative finding. Adhesion of the aneurysm to the artery, vein, or brain surface was confirmed during surgery.
3D VRFA-TSE T2 weighted-imaging was superior to conventional T2-weighted imaging or cerebral angiography in detecting the adhesion between an aneurysm and the brain surface or an artery. 3D VRFA-TSE T2 weighted-imaging detected lenticulostriate arteries even if cerebral angiography could not detect them. It could also identify large cerebral veins. However, 3D VRFA-TSE T2-weighted imaging could not identify narrow adhesion points. In such cases, a detailed evaluation is required.
3D VRFA-TSE can contribute to the preoperative evaluation of middle cerebral aneurysms by providing detailed anatomical information.
