High-resolution 3-Tesla magnetic resonance neurography of musculocutaneous neuropathy

MRN findings of lateral antebrachial cutaneous nerve impingement in a collegiate athlete

Dynamic compression of the lateral antebrachial cutaneous nerve (LABCN) occurs with forearm pronation when the LABCN becomes compressed by the lateral margin of the biceps tendon. LABCN compression is a rare occurrence and is often overlooked as an etiology for forearm pain. While this entity has been described in several case reports in the orthopedic literature, it has not yet been described in radiology literature. We present a case of LABCN compression by the biceps tendon which was suggested by high-resolution magnetic resonance neurography in combination with the clinical findings and was subsequently confirmed and corrected surgically.

Peripheral MR neurography: approach to interpretation

The magnetic resonance neurography (MRN) examination is rapidly becoming a part of the diagnostic algorithm of patients with peripheral neuropathy; however, because of the technical demands and the lack of required reading skills, the examination is relatively underutilized and is currently limited to a few tertiary care centers. The radiologists with interest in peripheral nerve imaging should be able to perform and interpret this examination to exploit its potential for widespread use. This article outlines the systematic, stepwise approach to its interpretation and a brief discussion of the imaging pitfalls.

High-resolution 3T MR neurography of the brachial plexus and its branches, with emphasis on 3D imaging

With advancement in 3D imaging, better fat-suppression techniques, and superior coil designs for MR imaging and the increasing availability and use of 3T magnets, the visualization of the complexity of the brachial plexus has become facile. The relevant imaging findings are described for normal and pathologic conditions of the brachial plexus. These radiologic findings are supported by clinical and/or EMG/surgical data, and corresponding high-resolution MR neurography images are illustrated. Because the brachial plexus can be affected by a plethora of pathologies, resulting in often serious and disabling complications, a better radiologic insight has great potential in aiding physicians in rendering superior services to patients.

Diffusion tensor imaging of forearm nerves in humans

PURPOSE

To implement a diffusion tensor imaging (DTI) protocol for visualization of peripheral nerves in human forearm.

MATERIALS AND METHODS

This Health Insurance Portability and Accountability Act (HIPAA)-compliant study was approved by our Institutional Review Board and written informed consent was obtained from 10 healthy participants. T(1) - and T(2) -weighted turbo spin echo with fat saturation, short tau inversion recovery (STIR), and DTI sequences with 21 diffusion-encoding directions were implemented to acquire images of the forearm nerves with an 8 channel knee coil on a 3T MRI scanner. Identification of the nerves was based on T(1) -weighted, T(2) -weighted, STIR, and DTI-derived fractional anisotropy (FA) images. Maps of the DTI-derived indices, FA, mean diffusivity (MD), longitudinal diffusivity (λ(//) ), and radial diffusivity (λ(⟂) ) along the length of the nerves were generated.

RESULTS

DTI-derived maps delineated the forearm nerves more clearly than images acquired with other sequences. Only ulnar and median nerves were clearly visualized on the DTI-derived FA maps. No significant differences were observed between the left and right forearms in any of the DTI-derived measures. Significant variation in the DTI measures was observed along the length of the nerve. Significant differences in the DTI measures were also observed between the median and ulnar nerves.

CONCLUSION

DTI is superior in visualizing the median and ulnar nerves in the human forearm. The normative data could potentially help distinguish normal from diseased nerves.