Imaging of entrapment and compressive neuropathies

Although the subject of entrapment and compressive neuropathies is huge, with dedicated textbooks on the subject, this article attempts to provide an up-to-date overview of the role of imaging in the diagnosis of nerve entrapment and compression syndromes. Entrapment and compressive neuropathies are a group of distinct syndromes secondary to physical constriction or irritation affecting peripheral nerves at specific anatomical sites in the body. Most nerve entrapment and compressive syndromes derive from an injury to the neurovascular components in a narrow anatomical passage. Because of their etiological diversity, which includes pressure, angulation, stretch, and friction, the pathophysiology of individual nerve entrapment syndromes differs widely. Neuropathy can result in considerable morbidity. Although the mainstay of achieving diagnosis is with clinical acumen and electrophysiological investigations, the increasing use of modern high-resolution imaging studies is of particular value in confirming physical findings and enabling determination of the extent of injury. Knowledge and familiarity of pertinent anatomy and appropriate choice of imaging modality is important for the radiologist to allow accurate interpretation of site and etiology of nerve entrapment and compression as well as ascertaining possible alternative diagnoses.