Motivation: Conventional in vivo brain MRE is challenging, requiring an external tamper, which can be expensive, difficult to operate, and inefficient given the mechanical shielding of the skull. Goal(s): To develop a robust method to simultaneously measure both the shear modulus, and the diffusion tensor fields throughout the brain using pulsations from the heart. Approach: We simultaneously measure both the displacement and diffusion tensor fields by cardiac gated displacement-encoded acquisitions. Results: The DT parameters vary significantly throughout the cardiac cycle. The shear modulus maps show white matter is stiffer than gray matter. Differences in stiffness across various white matter tracts were also observed. Impact: This study could facilitate the use of intrinsic brain tissue motion induced by cardiac pulsations to diagnose subtle neurological diseases.
Magdoom et al. (Tue,) studied this question.