MR Neurography — Imaging Peripheral Nerves

MR Neurography

Nerves are hard to see — MR neurography is a dedicated technique that makes peripheral nerves and plexuses visible when clinical and electrical tests aren’t enough.

How it works

MR neurography uses high-resolution, nerve-selective sequences (heavily T2-weighted with fat suppression, often 3D) that highlight nerve signal and suppress background, plus diffusion techniques to trace nerves. Normal nerves are barely brighter than muscle; an injured nerve becomes enlarged and T2-hyperintense.

It complements nerve conduction studies/EMG — imaging shows where and what (compression, mass, discontinuity), which electrical tests can’t localise anatomically.

Main uses

Entrapment/neuropathy: ulnar at the elbow, median (carpal tunnel), common peroneal, tarsal tunnel, pudendal.
Plexus: brachial and lumbosacral plexus — trauma, tumour infiltration, radiation change, thoracic outlet.
Trauma: nerve transection vs neuroma-in-continuity, guiding surgical repair.
Tumours: schwannoma, neurofibroma, and the target/split-fat signs of nerve-sheath tumours.

Practical notes

It is technically demanding, needs the right coils and a targeted protocol, and is best at higher field strength. Requesting a specific nerve/region and clinical question greatly improves the study.

Reference: Chhabra A et al. MR neurography: past, present, and future. AJR Am J Roentgenol 2011;197:583–91.

Educational summary for clinicians; interpret with electrodiagnostics. Not medical advice.