MR Neurography Adds Diagnostic Value in Proximal and Multi-Nerve Neuropathies

Diagnosing peripheral neuropathies of the upper limb remains a significant clinical challenge due to the overlapping presentations of entrapment syndromes, inflammatory plexopathies, and systemic polyneuropathies [1, 2]. While nerve conduction studies serve as the primary diagnostic tool, they frequently lack the structural detail necessary to identify specific etiologies or precise anatomical locations of nerve compromise [3, 4]. High-resolution ultrasound and magnetic resonance neurography (an imaging technique optimized for visualizing peripheral nerves using specialized sequences to suppress fat and vessel signals) have emerged as vital adjuncts, offering the ability to visualize nerve cross-sectional area (the measurement of a nerve's thickness in a transverse plane) and signal changes that correlate with axonal distortion or edema [5, 6]. In a recent exploratory subanalysis of 800 patients, researchers found that magnetic resonance neurography provided additional diagnostic value in 94.9% of cases where one modality surpassed the other, particularly when identifying proximal nerve lesions (odds ratio 5.72, 95% confidence interval: 3.42 to 9.56) or multi-nerve involvement (odds ratio 1.65, 95% confidence interval: 1.03 to 2.63) [7]. Conversely, high-resolution ultrasound proved most beneficial when magnetic resonance imaging was limited by metal artifacts [7]. These findings provide a clinical rationale for choosing imaging based on the suspected lesion site and the presence of multi-regional pathology to improve diagnostic accuracy in routine practice.