Lumbosacral Plexus MR Neurography in Autoimmune Nodopathy: A Quantitative Analysis

Area of Science:

• Neurology
• Radiology
• Immunology

Background:

• Autoimmune nodopathy (AN) is a rare condition affecting the nervous system.
• Accurate diagnosis and monitoring of treatment efficacy are crucial for managing AN.
• Lumbosacral plexus magnetic resonance neurography (L-MRN) has emerged as a potential imaging modality.

Purpose of the Study:

• To evaluate the diagnostic utility of L-MRN in patients with AN.
• To identify characteristic imaging abnormalities associated with AN using L-MRN.
• To explore the role of radiomics in assessing treatment response in AN.

Main Methods:

• Retrospective analysis of 16 AN patients and 18 healthy volunteers.
• L-MRN imaging to assess cauda equina and nerve root enhancement, including the 'sleeve sign'.
• Measurement of nerve root cross-sectional area (CSA) and nerve-to-muscle T2 signal intensity (nT2s); longitudinal follow-up with radiomics analysis.

Main Results:

• L-MRN revealed characteristic findings in AN patients: 100% cauda equina enhancement, 90.9% preganglionic nerve enhancement, 72.7% postganglionic enhancement, and 68.8% sleeve sign.
• Significantly larger nerve root CSA and nT2s were observed in AN patients compared to controls (p<0.001).
• Radiomic features correlated with clinical improvement, with changes in L5L_NGTDM_Strength and L5R_GLCM_IMC1 associated with disability score changes.

Conclusions:

• Lumbosacral plexus MRN is a valuable diagnostic tool for autoimmune nodopathy.
• Imaging biomarkers identified through L-MRN and radiomics can aid in assessing treatment efficacy.
• L-MRN provides crucial insights into the structural and inflammatory changes in AN.