Albeit being rarely used, high- frequency sonography is an important method for the imaging of the peripheral nerves. For the examination of superficially located nerves, currently available transducers with frequencies between 12-17 MHz offer a better axial resolution than even MRI. Sonography is superior to MRI especially for the examination of the nerves of the upper extremity. Main indications for the sonography of the nerves are entrapment syndromes, traumatic injuries of the nerves, tumors, polyneuropathies and sonographically guided interventions. The sensitivity of sonography and electrophysiology in the diagnosis of carpal tunnel syndrome and cubital tunnel syndrome are comparable. The combination of ultrasonography with electrophysiological studies increases the diagnostic yield in carpal and cubital tunnel syndromes. Sonography provides informations for planning peripheral nerve surgery and is helpful in evaluating postoperative complications. In selected cases, sonography can detect nerve lesions that require operative therapy earlier than electrophysiology. High-frequency ultrasonography is gaining increasing importance in the routine instrumental diagnostics of peripheral nerve lesions.
Keywords: high-resolution sonography, nerve neurosonography