Echo-planar imaging of intravoxel incoherent motion.

TLDR

The recently established single‑shot echo‑planar imaging of intravoxel incoherent motion (IVIM) has been applied to study water perfusion in phantoms and in vivo diffusion and perfusion in cat and human brains. Phantom experiments confirm that IVIM‑derived perfusion levels produce reproducible signal changes consistent with theory, while in vivo brain studies yield reliable diffusion coefficients, reveal anisotropic diffusion in white matter, and estimate up to 14 % perfusion fraction in gray matter.

Abstract

The recently established single-shot technique of echo-planar imaging of intravoxel incoherent motion (IVIM) for determining and imaging the variations of microscopic motions of water has been applied to studies of water perfusion in phantoms and to in vivo studies of diffusion and perfusion in cat and human brains. The phantom results demonstrate that perfusion levels comparable with those found in vivo have easily observable and reproducible effects on signal amplitude that are consistent with previous IVIM theory. Reliable measurements of the diffusion coefficient in various types of brain tissue have been obtained. The results for white matter are consistent with the existence of anisotropic diffusion in oriented bundles of myelinated nerve fibers. The results for gray matter can be fitted to the IVIM theory and suggest a value of up to 14% for the fraction of the signal contributed by randomly perfusing fluid in normal cerebral cortex.