Group-velocity inversion in MR elastography on skeletal muscles
Sack I, Rump J, Papazoglou S, Klatt D, Hamhaber U, Braun J
Institute of Radiology
MR elastography (MRE) enables to monitor the full vector-field of a harmonic displacement so that anisotropic elastic parameters of the investigated tissue are accessible. Here, a strategy is introduced for deducing two independent shear moduli from 2D wave images in MRE based on the group velocity of bulk shear waves. The approach utilizes fast SSFP-MRE and automatic detection of direction-dependent wave velocities. The new method is demonstrated on the biceps of 5 healthy volunteers revealing that the shear modulus parallel to the muscle fibers is about 5 times larger than perpendicular to them.