Magnetic Resonance Neurography for Evaluation of Peripheral Nerves

Abstract

Peripheral nerve injuries (PNIs) continue to present both diagnostic and treatment challenges. While nerve transections are typically a straightforward diagnosis, other types of PNIs, such as chronic or traumatic nerve compression, may be more difficult to evaluate due to their varied presentation and limitations of current diagnostic tools. As a result, diagnosis may be delayed, and these patients may go on to develop progressive symptoms, impeding normal activity. In the past, PNIs were diagnosed by history and clinical examination alone or techniques that raised concerns regarding accuracy, invasiveness, or operator dependency. Magnetic resonance neurography (MRN) has been increasingly utilized in clinical settings due to its ability to visualize complex nerve structures along their entire pathway and distinguish nerves from surrounding vasculature and tissue in a noninvasive manner. In this review, we discuss the clinical applications of MRN in the diagnosis, as well as pre- and postsurgical assessments of patients with peripheral neuropathies.

Nerve entrapment syndromes of the upper limb: a pictorial review

“…2 Dr Jones & Partners Medical Imaging, Prospect, SA 5082, Australia. 3 Department of Medical Imaging, Flinders Medical Centre, Flinders Drive, Bedford Park, SA 5042, Australia. 4 Department of Radiology, Royal Adelaide Hospital, Port Rd, Adelaide, SA 5000, Australia.…”

“…In entrapment neuropathy, MRI can reveal proximal enlargement and swelling with increased T2 signal [ 1 ]. There is flattening of the nerve at the site of entrapment [ 3 ]. Muscular changes are more easily appreciated on MRI than ultrasound, with denervation oedema acutely and atrophy in more longstanding cases [ 2 ].…”

“…MRI of peripheral nerves predominantly utilises T1-weighted and fluid-sensitive sequences [ 2 ]. Magnetic resonance neurography (MRN) is a technique which utilises the longer T2 isolation time of nerves to better image them [ 3 ]. Benefits of MRI include better visualisation of deep nerves and high contrast resolution.…”

Traumatic injury to peripheral nerves

“…Although the focus here is on EDx assessment of PNIs, it should be recognized that there are significant ongoing advances in imaging techniques that complement the functional assessment offered by EDx studies. [17][18][19][20]…”

“…Because it is generally not feasible to distinguish between Sunderland grades 2 to 4 based on EDx findings, this article focuses primarily on the Seddon classification. Although the focus here is on EDx assessment of PNIs, it should be recognized that there are significant ongoing advances in imaging techniques that complement the functional assessment offered by EDx studies 17–20 …”