Utility of Non-Contrast CT and MRA Fusion Images for Depicting Occluded Vessels in Mechanical Thrombectomy.

Objective: Mechanical thrombectomy (MT) for acute ischemic stroke usually requires blind procedures when endovascular devices are advanced distal to the occlusion site. Visualization of vascular structures distal to the occlusion could potentially enable safer procedures and more effective recanalization. We report the usefulness of fusion images using non-contrast CT and MRA with Ziostation REVORAS (Ziosoft, Tokyo, Japan). Case Presentation: Fusion images were created for 8 consecutive patients who underwent MT at our institution (Tsuruoka Municipal Shonai Hospital). Non-contrast CT and time-of-flight MRA data were processed using the 3D analysis function of Ziostation REVORAS. Fluoroscopy-like images and vascular structures distal to the occlusion were depicted using non-contrast CT, and vessels proximal to the occlusion site were visualized using MRA. These datasets were used to create fusion images displaying vascular structures distal to the occlusion with bone information. The images enabled simulation of the working angle and visualization of the thrombus extent, and were applicable to both anterior and posterior circulation. The mean image creation time was 3 min 26 s, and image creation was completed within 4 min in all cases. The vascular anatomy depicted on the fusion images was concordant with post-MT DSA in all cases. Conclusion: Fusion images may represent a useful adjunctive imaging tool for achieving safe and effective recanalization during MT.