Journal of Neuroradiology (2011) 38, 265—274 REVIEW High-resolution 3T MR neurography of radial neuropathy Neurographie RM 3T haute resolution de la neuropathie radiale Neda Faridian-Aragh a , Majid Chalian a , Theodoros Soldatos a , Gaurav K. Thawait a , E. Gene Deune b , Allan J. Belzberg c , John A. Carrino a , Avneesh Chhabra a,* a The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Hospital, 601 North Caroline Street, JHOC 3262, Baltimore, MD 21287, USA b Orthopedic Hand Division, Johns Hopkins Hospital, Baltimore, MD, USA c Department of Neurosurgery, Johns Hopkins Hospital, Baltimore, MD, USA Available online 22 July 2011 KEYWORDS Radial nerve; Radial neuropathy; High-resolution MRI; MRI Summary The radial nerve is a continuation of the posterior cord of the brachial plexus and one of the major nerves that provide motor and sensory innervations to the forearm. MR imag- ing evaluation of the radial nerve pathology has been described in scattered case reports. Current high-field MR scanners enable high resolution and high contrast imaging of the periph- eral nerves. This article reviews the 3Tesla magnetic resonance neurography imaging of radial nerve anatomy and various pathologies affecting it with relevant case examples. © 2011 Elsevier Masson SAS. All rights reserved. Introduction Radial neuropathy is relatively uncommon [1] and comes third in the order of frequency among all the neuropathies that involve the large mixed nerves of the body [2]. Diagno- sis of radial neuropathy is often difficult due to the vague presenting symptoms and frequently inconclusive results of the electrodiagnostic studies [1,3]. High-resolution ultra- sound (US) and magnetic resonance neurography (MRN) have proven to be useful tools in confirming the presence of neu- ropathy and defining the source, region and extent of the * Corresponding author. Tel.: +410 382-3863; fax: +410 502-6454. E-mail addresses: achhabr6@jhmi.edu, nedafaridian@gmail.com (A. Chhabra). abnormality [4—6]. Although MRN is more expensive than US, it is less operator-dependent and can depict subtle abnormal signal intensity changes in the affected nerve and dener- vated muscles, thereby confirming neuropathy. This article provides an overview of radial nerve anatomy and a spec- trum of pathologies on 3Tesla (T) MRN imaging. Anatomy of the radial nerve Posterior cord of the brachial plexus, which has contribu- tions from C5 to T1 nerves, gives rise to the radial nerve. The radial nerve courses posterior to the proximal seg- ment of the axillary artery. In the arm, it courses around the posterior aspect of the humerus in the spiral groove from medial to lateral (Fig. 1), and pierces the lateral 0150-9861/$ – see front matter © 2011 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.neurad.2011.05.006