Fig. 3.

Comparison of oscillatory strain fields in the brain from MRE during harmonic skull motion (top row) and from DMD of tagged MRI during impulsive skull motion (bottom row). (a) Displacement $u_x$ ( $x$  = LR, $y$  = AP). (b) Cartesian ( ${\epsilon }_{xy}$ ) strain fields. (c) T1 images in their respective “native” spaces. (d) Rigidly registered T1 images (centroids in green). (e) Radial-circumferential strain ( ${\epsilon }_{r\theta }$ ) fields after rigid registration. (f) T1 images registered to MNI atlas using SyN. (g) ${\epsilon }_{r\theta }$ strain fields after nonlinear registration to MNI atlas. Scale bars 10 cm.