FIGURE 2.

Flowchart of the image processing pipeline to estimate strain and strain rate indices. Velocity data is corrected for phase shading artifacts and denoised with a 3D anisotropic diffusion filter. Each voxel is tracked through the temporal cycle to obtain displacement maps. Spatial gradients of velocity and displacement lead to strain and strain rate maps, respectively. Lagrangian strains L were calculated as were the strain rates, SR. In addition to the eigenvalues of the tensors, two invariants were computed from the strain tensor: volumetric (L_vol) and maximum shear strain (L_max) and one invariant for the shear strain rate: maximum shear strain rate: SR_max.