Evaluation of slow flow measurement with low b-value diffusion tensor imaging using fluid phantoms in comparison with 4D-flow

Motivation: Is low b-value diffusion tensor imaging (low-b DTI) useful for analyzing cerebrospinal fluid flow, which is a slow and complex flow that is difficult to measure?Goal(s): To validate low-b DTI for analyzing the slow flow. Approach: To compare low-b DTI with 4D-flow in the fluid phantom where water flowed at a constant slow rate. Results: A strong correlation between the mean diffusivity of Low-b DTI and the mean square of deviation of velocity of 4D-flow, which is supported by the theory that these correlate in laminar flow. Impact: If low b-value diffusion tensor imaging is useful for analyzing slow and complex flows of cerebrospinal fluid, it should contribute to understanding the pathogenesis of various diseases in which impaired cerebrospinal fluid clearance system may be part of the etiology.