The purpose of this study was to explore the feasibility of Magnetic Resonance Elastography (MRE) measurement for quantification of the stiffness change of the shoulder rotator cuff muscle compared with Shear Wave ultrasound Elastography (SWE). Six porcine shoulders were used in this study. MRE and SWE measurement of the rotator cuff muscle was performed before and after the rotator cuff tendon detachment. Stiffness values were significantly lower after the tendon detachment in both MRE and SWE measurements (p<0.05). This result suggests that MRE could be a feasible method for quantification of the rotator cuff muscle stiffness as well as SWE.