Yuxi Pang1
1Dept. of Radiology, University of Michigan, Ann Arbor, MI, United States
1Dept. of Radiology, University of Michigan, Ann Arbor, MI, United States
Anisotropic R2 and R2* relaxation has been documented in white matter, yet the
underlying relaxation mechanisms still remain not well understood. This work is
to propose a generalized magic angle effect model to better
characterize the reported anisotropic transverse relaxation.
FIGURE 2. Measurements and modeling of anisotropic R2 in the human
brain white matter in vivo at 3T. The measured
(black triangle) and the fitted anisotropic myelin water R2 (2A) and
intra- and extracellular (IE) water R2 (2B) using
the gMAE model with a phase offset φ_0 (Fit A, solid red lines), and the previous model (Fit B, dashed blue lines) without φ_0 from the
original publication [REF. 2]. The fitting residuals, defined as ΔR_2=Fitted-Measured, are respectively shown for myelin water (2C) and IE water (2D).
FIGURE 3. A schematic of water molecular restricted rotational diffusion (3A) and anisotropic translational diffusion (3B) in the human brain white matter.
