MR neurography of the brachial plexus in adult and pediatric age groups: evolution, recent advances, and future directions

ABSTRACT

Introduction: MR neurography (MRN) of the brachial plexus has emerged in recent years as a safe and accurate modality for the identification of brachial plexopathies in pediatric and adult populations. While clinical differentiation of brachial plexopathy from cervical spine-related radiculopathy or nerve injury has long relied upon nonspecific physical exam and electrodiagnostic testing modalities, MRN now permits detailed interrogation of peripheral nerve anatomy and pathology, as well as assessment of surrounding soft tissues and musculature, thereby facilitating accurate diagnosis. The reader will learn about the current state of brachial plexus MRN, including recent advances and future directions, and gain knowledge about the adult and pediatric brachial plexopathies that can be characterized using these techniques.

Areas Covered: The review details recent developments in brachial plexus MRN, including increasing availability of 3.0-T MR scanners at both private and academic diagnostic imaging centers, as well as the advent of multiple new vascular and fat signal suppression techniques. A literature search of PubMed and SCOPUS was used as the principal source of information gathered for this review.

Expert Opinion: Refinement of fat-suppression, 3D techniques and diffusion MR imaging modalities has improved the accuracy of MRN, rendering it as a useful adjunct to clinical findings during the evaluation of suspected brachial plexus lesions.

KEYWORDS:

• Brachial plexus
• MR neurography
• MRN
• peripheral nerve injury
• peripheral nerve-sheath tumor

Article highlights

• MR neurography (MRN) of the brachial plexus has emerged in recent years as a sensitive and specific modality for the identification of brachial plexopathies in both pediatric and adult populations.

• Diagnosis of brachial plexopathy is generally multi-modal, and may involve any combination of electromyography (EMG), nerve conduction studies, MR imaging, or CT myelography, in association with clinical exam findings; however, among these modalities, MRN provides the most detailed anatomic interrogation of brachial plexus structures.

• 3T and 3D imaging of the brachial plexus allow depiction of nerve anatomy and pathology, such as injury, inflammation, and tumors in exquisite detail.

• Brachial plexus MRN offers considerable utility in the context of pre-operative planning for nerve injuries or tumors.

• Diffusion-tensor imaging allows depiction of nerve architecture and tumor infiltration primarily in the research setting today, but it will play a larger role in the future.

Declaration of interest

A Chhabra serves as a consultant for ICON Medical and Treace Medical Concepts Inc. AC also receives royalties from Jaypee and Wolters. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.