Diffusion weighted fMRI at 1.5 T

摘要: Functional magnetic resonance imaging (fMRI) is capable of detecting task-induced blood oxygenation changes using susceptibility sensitive pulse sequences such as gradient-recalled echo-planar (EPI). The local signal increases seen in the time course are believed to be due an increase oxygen delivery that incommensurate with demands. To help isolate sources functional changes, authors have incorporated various forms diffusion weighting into EPI characterize apparent mobility functionally modulated protons. Results suggest majority at 1.5 T arises from protons coefficients approximately four or five times higher than brain tissue. This implies significant either within vascular space perivascular occupied by cerebrospinal fluid.