Magnetic Resonance Diffusion Imaging In Experimental Brain Research

Abstract

Diffusion-weighted MR imaging has great potential in studies of experimental brain research. Heavy diffusion-weighting is useful in determining the presence of anisotropic water proton diffusion in myelinated white matter structures in cat brain and spine. Large differences in apparent diffusion rates are observed between white matter tissues compared to gray, which does not displayed anisotropy. However, large decreases in apparent diffusion rates are observed in gray matter following experimentally-induced cerebral ischemia. This change in diffusion behavior is apparent within minutes upon ischemic onset and can be reversed upon reperfusion. Motion artifacts, often severe in spin-echo diffusion studies requiring 10-20 minutes to perform, can be largely eliminated by echoplanar, high-speed (150 msec) diffusion experiments.