Application of real-time sonoelastography in musculoskeletal diseases related to physical medicine and rehabilitation.

Real-time sonoelastography is a recently developed ultrasound-based technique that evaluates tissue elasticity in real time, and it is based on the principle that the compression of tissue produces a strain (displacement) that is lower in hard tissue and higher in soft tissue. Real-time sonoelastography provides information on tissue elasticity, in addition to the shape or vascularity, which is obtained via B-mode ultrasound. Similar to B-mode ultrasound, freehand manipulation with the transducer and real-time visualization are now available for real-time sonoelastography in actual clinical practice. Tissue elasticity not only varies among different tissues but also seems to reflect disease-induced alternations in tissue properties. Real-time sonoelastography was recently applied to the normal and pathologic tissues in muscle and tendon disorders, and it showed promising results and new potentialities. Therefore, it is expected to be a useful modality for providing novel diagnostic information in musculoskeletal diseases because tissue elasticity is closely related to its pathology. It can also be used as a research tool to provide insight into the biomechanics and pathophysiology of tissue abnormality.