High-resolution ultrahigh-field MRI of stroke

Magn Reson Imaging. 2005 May;23(4):539-48. doi: 10.1016/j.mri.2005.02.010.

Abstract

Background: Ultrahigh-field MRI at 8 T offers unprecedented resolution for imaging brain structures and microvasculature.

Objective: The aim of this study is to apply high-resolution MRI for stroke imaging and to characterize findings at 1.5 and 8 T.

Methods: Seventeen subjects with minor ischemic infarcts were studied using T2-weighted gradient echo (GE) and rapid acquisition with relaxation enhancement (RARE) images at 8 T with resolution up to 200 microm. In 10 subjects, T1- and T2-weighted fast spin echo (FSE) and fluid-attenuated inversion recovery (FLAIR) images were also acquired at 1.5-T MRI.

Results: The 8-T images showed infarcts as sharply demarcated areas of high-signal intensity (n=21) and revealed more infarctions than 1.5-T images (n=14) (P<.003). The low-signal intensity areas that surrounded infarctions were suggestive of hemosiderin deposits. The 8-T characteristics of microvessels terminating within the infractions were distinct from normal vasculature. The 8-T images revealed an angioma at the site of a second stroke, not apparent on 1.5-T images.

Conclusions: Ultrahigh-field MRI at 8 T is feasible for stroke imaging. The 8-T MRI visualized infarcts and microvasculature with high resolution, revealing infarcts and vascular pathologies that were not apparent at 1.5 T.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Chi-Square Distribution
  • Contrast Media
  • Female
  • Humans
  • Image Enhancement
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Statistics, Nonparametric
  • Stroke / pathology*

Substances

  • Contrast Media