Figure 5.

MRE investigation of stiffness changes in the loaded and unloaded biceps brachii. The MRE acquisition of the right arm was performed on a healthy male subject lying in the right lateral decubitus position as described in Dresner et al. (135). The subject was imaged in a coronal plane while supporting different amounts of weight. The image on the left is a reference image indicating the orientation of the muscle and the location of the driver, which was placed above the distal biceps tendon and vibrated in the through-plane direction. The three images on the right show wave images from the MRE acquisitions performed with the subject holding 0-, 4-, and 8-kg loads. The shear wavelength in the muscle can be seen to increase with the increasing muscle load, indicating that the stiffness of the muscle has significantly increased. (Courtesy of Dr. Yogesh Mariappan, Mayo Clinic, Rochester, MN.)