Sonographic diagnostics in peripheral nerve diseases of the upper extremities

High-resolution ultrasonography (HRUS) devices using high-frequency linear probes and new improved imaging processing technologies are increasingly being utilized worldwide for the investigation of peripheral nerve disorders. The HRUS allows the detection of alterations even in single fasciculi and the perineurium and provides important additional information on morphological aspects and the etiology of peripheral nerve pathology. It has become a valuable tool in the daily clinical practice supporting the neurological examination and electrophysiological testing in setting the correct diagnosis. It is especially useful in detecting structural abnormalities of the nerves caused by compression, trauma, tumors, inflammation and a variety of non-neoplastic conditions, including nerve torsion. The low cost in comparison to magnetic resonance (MR) neurography, the possibility of a dynamic examination, assessing long nerve segments in a short time, bedside availability, non-invasive testing and the possibility of US-guided nerve blocks and therapies make HRUS the ideal imaging tool for peripheral nerve diseases. This article describes the main applications of HRUS for peripheral nerve diseases of the upper arm.