MR diffusion imaging of the human brain.

Magnetic resonance diffusion imaging reflects the water mobility at each point in a tomographic image. We have studied brain water diffusion in 18 normal volunteers to identify the different factors that can influence diffusion measurements in vivo. Our results show that both the measurement accuracy and the measured diffusion coefficient strongly depend on the experimental parameters, in particular, echo and diffusion time, cardiac gating, and diffusion encoding gradient direction.