３Ｔ‐ＭＲＩによるｓｔｒｏｋｅ ＭＲＩの有用性と問題点

Abstract

We report usefulness of 3 tesla MRI and new ischemic findings on gradient echo-type T2*-weighted images (T2*-WI) in patients with acute ischemic stroke We defined two ischemic findings regarding the vessels (cortical vessel enlargement sign; hypointensity of the cortical vessels and brush sign; hypointensity of the deep white matter vessels) and a decreased intensity in the ischemic parenchyma (tissue ischemic sign) on the T2*-WI. These ischemic findings were compared with the hypoperfused area detected by the FAIR images and the ROI comparison between the hypoperfusion on the FAIR imaging and the “tissue ischemic sign” on the T2*-WI was conducted by calculating the asymmetry ratios. This cortical vessel enlargement sign was seen in all patients with ICA or MCA occlusion. The area of the vessel ischemic signs was almost the same or less than the hypoperfused area shown by the PWI images. In patients who showed tissue ischemic sign, the ROI measurement demonstrated more hypoperfusion by PWI than in the sign (-) group. 3T MRI is therefore useful to evaluate ischemic conditions in acute stroke patients.