Elastography: Applications in Peripheral Nerves

Abstract

The biomechanical properties of soft tissues reflect to some degree the pathophysiology of musculoskeletal disorders. Conventional gray-scale sonography has been widely used as a first-line approach for musculoskeletal disorders because of the advantage of real-time access. Sonoelastography, which we refer to here as strain elastography (SE), requires manual compression vibration and is a modality for quantitatively measuring the elasticity of soft tissue through conventional gray-scale sonography with estimated Young’s modulus or semi-quantitative values as strain ratios. By using the semi-quantitative values of strain ratios, SE has demonstrated promising preliminary results for the diagnosis of masses of the liver, breast, pancreas, prostate, and thyroid, with defined cutoff values. In peripheral nerve disorders, SE could be preferable in clinical practice for detecting the biomechanical changes of tendons, muscles, and ligaments surrounding the nerve, to diagnose and plan preoperational or interventional management. Recently, by using SE, several studies have provided insight into the biomechanical properties and pathophysiological changes associated with entrapment neuropathy as typified by carpal tunnel syndrome. In this presentation, the current knowledge of sonoelastographic techniques and their use for peripheral nerve disorders will be reviewed.