Frequency-dependent diffusion-relaxation multidimensional MRI of the human brain

Using an integrative acquisition and processing pipeline that joins concepts from oscillating gradients, tensor-valued encoding, and diffusion-relaxation correlation, we comprehensively explored microstructure and local chemical composition in the human brain. Using both frequency-dependent and tensorial aspects of the encoding spectrum b(ω), we designed an in vivo, whole brain, 40-min 7D D(ω)-R1-R2 distribution acquisition protocol at 2mm isotropic resolution. Scanning eleven healthy participants, we demonstrated frequency/time-dependent changes of diffusion-relaxation correlations measures in the human brain. Finally, intra-scan test–retest repeatability of a range of reconstructed parametric maps was investigated.