Magnetic resonance elastography: An imaging technique used to measure the elasticity of tissue by gently shaking the tissue in a magnetic resonance imaging (MRI) machine. The technique employs standard MRI equipment with a few modifications and a vibrating metal plate placed on the skin. Magnetic resonance elastography (MRE) works by measuring the wavelength of the vibrations sent through the tissues. Pulsing the magnetic field in the MRI scanner in tune with the mechanical vibrations freezes the pattern of waves, permitting the wavelength to be measured. The elasticity of the tissue can then be calculated using this measure. MRE is being applied to the study of skeletal muscle since the stiffness of a muscle changes during muscle contraction. The technique may also be applied to breast cancer and other tumors that tend to be harder than the surrounding normal tissue.