Acute Ischemic Infarction Defined by a Region of Multiple Hypointense Vessels on Gradient-Echo T2*MR Imaging at 3T

Abstract

BACKGROUND AND PURPOSE: During the hyperacute phase of stroke, multiple hypointense vessels were identified specifically in the ischemic territory on gradient-echo T2{*}-weighted MR images (GRE-T2{*} WI) at 3T. The area was named a ``region of multiple hypointense vessels (RMHV).{''} The aim of this study was to assess the usefulness of RMHV for the diagnosis of acute ischemic stroke (AIS) and to establish the relationship of this finding to other MR imaging studies. MATERIALS AND METHODS: Twenty patients with AIS underwent MR imaging at 3T consisting of GRE-T2{*}, diffusion-weighted images (DWI), and perfusion-weighted images (PWI) within 6 hours of symptom onset and follow-up images at 72 hours. RMHV was defined as an area containing multiple hypointense vessels strictly in the region of the ischemic territory on GRE-T2{*}. The RMHV volume on GRE-T2{*}, initial ischemic lesion volumes on DWI, PWI maps, and on follow-up images were measured and compared with the RMHV volume. RESULTS: RMHV on GRE-T2{*} was identified in 20 patients. There was no significant difference between the ischemic lesion volumes on mean transit time (247.3 +/- 88.1 mL), time-to-peak (228.6 +/- 88.8 mL), cerebral blood flow (200.6 +/- 89.7 mL), RMHV on GRE-T2{*} (214.4 +/- 86 mL), and the infarct volume at 72 hours (210.3 +/- 90.4 mL) (P = .975). CONCLUSIONS: RMHV on GRE-T2{*} can be used as a supportive imaging finding for the diagnosis of hyperacute ischemic stroke. RMHV volume provides information that is in accordance with the infarct volume at 72 hours and the data supplied by PWI.