Entrapment neuropathies of the upper extremity nerves

Purpose of Review This article reviews recent updates in the imaging for diagnosis and characterization of upper extremity nerve entrapments (UENE). We examine in detail the use of ultrasound and MRI, including state-of-the-art techniques such as dynamic nerve motion assessment, tissue elasticity measurement, and MR neurography. Recent Findings Ultrasound and MRI are the two advanced modalities most frequently used to assess UENE. MRI remains technically challenging, though techniques of MR neurography have steadily improved. Ultrasound is operator-dependent, but has dynamic and realtime imaging capabilities and no contraindications. New comparative techniques of measurement and elasticity assessment show promise for improved diagnostic accuracy. Summary Up-to-date imaging techniques for peripheral nerves in the upper extremity from the shoulder to the hand are discussed, with a focus on the most common UENE such as carpal tunnel syndrome and cubital tunnel syndromes. Technical challenges and limitations are reviewed, with a focus on the current and future state of imaging for UENE. Keywords Ultrasound Musculoskeletal Nerve MRI Neurography Entrapmen