Imaging of non-neurogenic peripheral nerve malignancy-a case series and systematic review

Recurrence of diffuse large B-cell lymphoma in sciatic and tibial nerves: A case report

Infiltration of peripheral or cranial nerves with lymphatic cells is a rare condition that is known as neurolymphomatosis (NL). The involvement could be primary or secondary and mostly occurs in patients with a history of B-cell lymphoma. The most common peripheral nerve involved is the sciatic nerve. Patients may present with painful or painless mononeuropathy or polyneuropathy, and MRI is the perfect modality to evaluate the suspicious clinical findings that may demonstrate enlargement, thickening, and enhancement of the involved nerve or an enhancing mass lesion in the course of the nerve. Biopsy can be safely performed to confirm the diagnosis. Few articles have reported the cases of peripheral nerve involvement by lymphoma as well as MRI features of this diagnosis. In this article, we report a case of NL using MRI, ultrasound, and pathologic features and also present a brief review of relevant literature.

Neuropathy Score Reporting and Data System: A Reporting Guideline for MRI of Peripheral Neuropathy With a Multicenter Validation Study

Background: A standardized guideline and scoring system would improve evaluation and reporting of peripheral neuropathies on MRI. Objective: The objective of this study was to create and validate a neuropathy classification and grading system, which we named the Neuropathy Score Reporting and Data System (NS-RADS). Methods: This retrospective study included 100 patients with nerve imaging studies and known clinical diagnoses. Experts crafted NS-RADS using mutually agreed-upon qualitative criteria for the classification and grading of peripheral neuropathies. Different classes were created to account for the spectrum of underlying pathologies: unremarkable (U), injury (I), neoplasia (N), entrapment (E), diffuse neuropathy (D), not otherwise specified (NOS), and postintervention state (PI). Subclasses were established to describe the severity or extent of the lesions. Validation testing was performed by 11 readers from multiple institutions with experience levels ranging from 3 to 18 years after residency. After initial reader training, cases were presented to readers, who were blinded to final clinical diagnoses. Interobserver agreement was assessed using correlation coefficients and the Conger kappa, and accuracy testing was performed. Results: Final clinical diagnoses included normal (n = 5), nerve injury (n = 25), entrapment (n = 15), neoplasia (n = 33), diffuse neuropathy (n = 18), and persistent neuropathy after intervention (n = 4). The miscategorization rate for NS-RADS classes was 1.8%. Final diagnoses were correctly identified by readers in 71-88% of cases. Excellent interreader agreement was found on the NS-RADS pathology categorization (κ = 0.96; 95% CI, 0.93-0.98) as well as muscle pathology categorization (κ = 0.76; 95% CI, 0.68-0.82]. The accuracy for determining milder versus more severe categories per radiologist ranged from 88% to 97% for nerve lesions and from 86% to 94% for muscle abnormalities. Conclusion: The proposed NS-RADS classification is accurate and reliable across different reader experience levels and a spectrum of peripheral neuropathy conditions. Clinical Impact: NS-RADS can be used as a standardized guideline for reporting peripheral neuropathies and improved multidisciplinary communications.

3D MR Neurography

High-resolution isotropic volumetric three-dimensional (3D) magnetic resonance neurography (MRN) techniques enable multiplanar depiction of peripheral nerves. In addition, 3D MRN provides anatomical and functional tissue characterization of different disease conditions affecting the peripheral nerves. In this review article, we summarize clinically relevant technical considerations of 3D MRN image acquisition and review clinical applications of 3D MRN to assess peripheral nerve diseases, such as entrapments, trauma, inflammatory or infectious neuropathies, and neoplasms.