MR Neurography: Diagnostic Imaging in the PNS

Abstract

The diagnostic work-up of peripheral neuropathies is often challenging and is mainly based on a combination of clinical and electrophysiological examinations. One of the most important difficulties is the accurate determination of the lesion site (lesion localization), lesion extension, and spatial lesion dispersion, which all represent essential diagnostic information crucial for finding the correct diagnosis and hence an adequate therapeutic approach. A typical pitfall in the conventional diagnostic reasoning is the differentiation between a distal, complete cross-sectional nerve lesion and a more proximally located, fascicular nerve lesion. Magnetic resonance neurography (MRN) has been proven to be capable of improving the diagnostic accuracy by providing direct, noninvasive visualization of nerve injury with high structural resolution even reaching the anatomical level of single nerve fascicles (fascicular imaging) and at the same time with large anatomical coverage. It is also feasible to detect structural nerve damage earlier and with higher sensitivity than gold-standard nerve conduction studies. The purpose of this study is to review the literature for current developments and advances in MRN for the precise spatial detection of nerve lesions in focal and non-focal disorders of the peripheral nervous system.

The Role of the Peripheral Nerve Surgeon in the Treatment of Pain

“…In our experience, ultrasound is highly operator dependent and not particularly sensitive for nerve compression or neuroma [77]. MR neurography has also become an accepted method for evaluating compression or injury of the peripheral nerves and has the added advantage of giving high-resolution imaging of the surrounding anatomy and associated inflammation [78][79][80]. Unfortunately, in many centers, it is not readily available.…”

MRI biomarkers of proximal nerve injury in CIDP

“…A high-resolution three-dimensional T2-weighted turbo spin echo (3D T2 TSE) sequence with fat and vessel signal suppression was used to locate the sciatic nerve in all spatial planes. [31][32][33] The parameters were as follows: TR = 2000, TE = 273, matrix size 216 9 143 9 143, resolution 1.25 9 1.25 9 0.7 mm 3 , scan duration 2:30 min ( Fig. 2A and B).…”

Magnetization transfer ratio quantifies polyneuropathy in hereditary transthyretin amyloidosis

“…MR neurography (MRN) can overcome some of the aforementioned diagnostic limitations by directly visualizing peripheral nerve lesions 11–21 . The quantitative MRN parameters, proton spin density ( ρ ) and apparent T2 relaxation time ( T2 app ), have previously proven their feasibility to detect subclinical and early nerve lesions as well as to differentiate between neuropathic patients and controls or even between different disease severities in several neuropathies 14–18 .…”