Reversibility of Ischemic Findings on 3-T T₂*-Weighted Imaging After Emergency Superficial Temporal Artery-Middle Cerebral Artery Anastomosis in Patients With Progressive Ischemic Stroke

—Two Case Reports—

Abstract

Vascular ischemic signs, i.e. multiple hypointense vessels in the ischemic territory, were identified by gradient echo-type 3-T T₂*-weighted magnetic resonance (MR) imaging in 3 patients with acute ischemia due to major vessel occlusion. Emergency superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis was performed in 2 patients with progressive stroke caused by bleeding-type moyamoya disease or severe MCA stenosis. Both patients were initially treated conservatively, but their neurological signs deteriorated. 3-T T₂*-weighted MR imaging detected funicular low signals in both patients indicating enhancement of cortical vessels or medullary veins. The area of the vascular ischemic signs was almost the same or smaller than the hypoperfusion area on perfusion-weighted MR imaging or single-photon emission computed tomography. Postoperatively, the vascular ischemic signs disappeared in both patients, suggesting a relationship with severe ischemia due to high-risk misery perfusion. Their postoperative course was uneventful, and MR imaging revealed no new cerebral ischemic lesions or cerebral hyperperfusion. The patient without surgery developed cerebral infarction in the area of the vascular ischemic signs. Vascular ischemic signs detected by 3-T T₂*-weighted MR imaging may represent a new predictor of high-risk misery perfusion, and may disappear after STA-MCA anastomosis performed in the subacute stage.