Flow-compensated intravoxel incoherent motion diffusion imaging

摘要

Purpose: The pseudo-diffusion coefficient D*in intravoxelincoherent motion (IVIM) imaging was found difficult to seize.Flow-compensated diffusion gradients were used to test thevalidity of the commonly assumed biexponential limit and todetermine not only D*, but also characteristic timescale s andvelocity v of the incoherent motion.Theory and Methods: Bipolar and flow-compensated diffu-sion gradients were inserted into a flow-compensated single-shot EPI sequence. Images were obtained from a pipe-shapedflow phantom and from healthy volunteers. To calculate theIVIM signal outside the biexponential limit, a formalism basedon normalized phase distributions was developed.