An assembly of devices, consisting of an electrically-powered pneumatic wave generator and a noninvasive vibration applicator, intended for use with a magnetic resonance imaging (MRI) system to provide a measure of tissue elasticity/stiffness. The generator is used outside the MRI scanner room and is connected by pneumatic tubing to the applicator, which is applied to the site of interest on the patient’s body while within the MRI scanner. The pneumatically-transferred vibrations are applied to the body and MRI images are taken to facilitate evaluation/diagnosis of the condition of tissues (e.g. liver, brain), including damage and tumours.