title: Brachial plexus injury: clinical manifestations, conventional imaging findings, and the latest imaging techniques.
abstract: Brachial plexus injury (BPI) is a severe neurologic injury that causes functional impairment of the affected upper limb. Imaging studies play an essential role in differentiating between preganglionic and postganglionic injuries, a distinction that is crucial for optimal treatment planning. Findings at standard myelography, computed tomographic (CT) myelography, and conventional magnetic resonance (MR) imaging help determine the location and severity of injuries. MR imaging sometimes demonstrates signal intensity changes in the spinal cord, and enhancement of nerve roots and paraspinal muscles at MR imaging indicates the presence of root avulsion injuries. New techniques including MR myelography, diffusion-weighted neurography, and Bezier surface reformation can also be useful in the evaluation and management of BPI. MR myelography with state-of-the-art technology yields remarkably high-quality images, although it cannot replace CT myelography entirely. Diffusion-weighted neurography is a cutting-edge technique for visualizing postganglionic nerve roots. Bezier surface reformation allows the depiction of entire intradural nerve roots on a single image. CT myelography appears to be the preferred initial imaging modality, with standard myelography and contrast material-enhanced MR imaging being recommended as additional studies. Work-up will vary depending on the equipment used, the management policy of peripheral nerve surgeons, and, most important, the individual patient.
authors.affiliation: Department of Computational Diagnostic Radiology and Preventive Medicine, University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo, Tokyo 113-8655, Japan. takeharu-yoshikawa@umin.ac.jp
authors.forename: Takeharu
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Naoto
authors.initials: N
authors.lastname: Hayashi
authors.forename: Shinichi
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tajiri
authors.forename: Naoki
authors.initials: N
authors.lastname: Yoshioka
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Masumoto
authors.forename: Harushi
authors.initials: H
authors.lastname: Mori
authors.forename: Osamu
authors.initials: O
authors.lastname: Abe
authors.forename: Shigeki
authors.initials: S
authors.lastname: Aoki
authors.forename: Kuni
authors.initials: K
authors.lastname: Ohtomo
mesh_terms: D001917:Brachial Plexus / Q000000981:diagnostic imaging / Q000293:injuries / Q000473:pathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000639:trends*; D009192:Myelography / Q000639:trends; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians' / Q000639:trends; D014057:Tomography, X-Ray Computed / Q000639:trends*