Susceptibility-weighted image features in AQP4-negative-NMOSD versus MS

Area of Science:

• Neuroimaging
• Neurology
• Radiology

Background:

• Neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) are distinct inflammatory demyelinating diseases.
• Differentiating aquaporin 4 (AQP4)-immunoglobulin G (IgG)-negative NMOSD from MS is clinically important.
• Susceptibility-weighted imaging (SWI) is sensitive to paramagnetic substances like iron and deoxhemoglobin.

Purpose of the Study:

• To characterize SWI features in AQP4-IgG-negative NMOSD, specifically paramagnetic rim and nodular lesions, and the central vein sign (CVS).
• To evaluate the utility of these SWI features as imaging biomarkers for distinguishing MS from AQP4-IgG-negative NMOSD.

Main Methods:

• Prospective recruitment of patients with AQP4-IgG-negative NMOSD, AQP4-IgG-positive NMOSD, and MS.
• Analysis of SWI features including paramagnetic rim and nodular lesions, and CVS.
• Determination of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for distinguishing MS from AQP4-IgG-negative NMOSD.

Main Results:

• AQP4-IgG-negative NMOSD patients showed significantly fewer paramagnetic rim and nodular lesions on SWI compared to MS patients.
• The rate of central vein sign (CVS) positivity was lower in AQP4-IgG-negative NMOSD (12%) than in MS (46%).
• SWI features (paramagnetic rim/nodular lesions) demonstrated high sensitivity (90.4%) and specificity (95.5%) for differentiating MS from AQP4-IgG-negative NMOSD.

Conclusions:

• SWI features, including paramagnetic rim or nodular hypointense signals and the presence of ≥3 CVS lesions, are valuable in distinguishing MS from AQP4-IgG-negative NMOSD.
• These SWI findings suggest potential as imaging biomarkers for differential diagnosis in neuroinflammatory diseases.