Effective Mechanical Thrombectomy for Posterior Circulation Ischemia Using Magnetic Resonance Imaging-based Arterial Structures

Abstract

To improve the success of mechanical thrombectomy, three-dimensional turbo spin-echo (3D-TSE) sequences on T2WI can be employed to estimate the vascular structure of the posterior circulation. In addition to the short imaging time of 3D-TSE T2WI (33 sec), it can visualize the outer diameter of the main cerebral artery, including the occluded vessels. However, to date, the efficacy of mechanical thrombectomy in the posterior circulation remains unclear, and safer and more efficient mechanical thrombectomy procedures are required. Assessment of the anatomical variations in the posterior circulation using 3D-TSE T2WI is valuable for access decisions, device selection, and safe device guidance and retrieval techniques to the target vessel. Herein, we present representative cases of basilar artery and posterior cerebral artery occlusions in our institute and describe the utility of preoperative 3D-TSE T2WI in these patients.

Keywords: 3D turbo spin-echo magnetic resonance imaging; mechanical thrombectomy; posterior circulation ischemia.

Fig. 1

Use of three-dimensional turbo spin-echo (3D-TSE) T2WI in mechanical thrombectomy for basilar artery occlusion. Diffusion-weighted imaging revealed areas of high signal intensity in the left cerebellum and bilateral occipital lobes (A). Magnetic resonance angiography revealed basilar artery occlusion (B). 3D-TSE T2WI visualized the arterial configuration of the occluded vertebral arteries and basilar artery (C). T2*WI depicted the thrombus with a low intensity, which was located in the lower segment of the basilar artery (arrow indicates the thrombus) (D). Successful recanalization was achieved after the endovascular procedure (E: pre-operation, F: post-stent deployment, G: post-percutaneous transluminal angioplasty).

Fig. 2

Utility of three-dimensional turbo spin-echo (3D-TSE) T2WI in determining the pathophysiology in patients with posterior circulation ischemic stroke. Diffusion-weighted imaging revealed a fresh infarction in both the anterior and posterior circulations (A). Magnetic resonance angiography (MRA) showed left posterior cerebral artery (PCA) occlusion (B). 3D-TSE T2WI (grayscale) and MRA (red) fusion imaging revealed fetal PCA occlusion with a small P1 segment (the dotted arrow indicates the posterior communicating artery; the arrowhead indicates the occluded P2 segment of the PCA; the solid arrow indicates the occlusion site) (C). Three-dimensional reconstruction of the fused 3D-TSE T2WI and MRA images (D).

Fig. 3

The application of three-dimensional turbo spin-echo (3D-TSE) T2WI was effective in mechanical thrombectomy for basilar artery occlusion. Diffusion-weighted imaging demonstrated high-intensity areas in the right occipital lobe, thalamus, and right cerebellum (A). Magnetic resonance angiography revealed upper basilar artery occlusion (B). 3D-TSE T2WI revealed vascular structures around the tip of the basilar artery, with the bilateral hypoplastic posterior communicating artery (C). Cerebral angiography detected atherosclerotic stenosis in the left vertebral artery and basilar artery occlusion (D). After a single pass of mechanical thrombectomy from the right superior cerebellar artery, successful recanalization was achieved with the right posterior cerebral artery remaining occluded (E–G).