Characterizing iron deposition in multiple sclerosis lesions using susceptibility weighted imaging

Area of Science:

• Neuroimaging
• Neurology
• Biomarkers

Background:

• Multiple sclerosis (MS) diagnosis and monitoring rely on magnetic resonance imaging (MRI).
• Conventional MRI sequences may not fully capture the complexity of MS lesions.
• Investigating novel imaging techniques for enhanced lesion characterization is crucial.

Purpose of the Study:

• To determine if susceptibility weighted imaging (SWI) identifies distinct multiple sclerosis (MS) lesion characteristics compared to conventional MRI.
• To explore the relationship between iron deposition patterns visualized by SWI and MS lesion features.

Main Methods:

• Twenty-seven MS patients underwent brain MRI at 1.5 T, 3 T, and 4 T, including T1, T2, FLAIR, and SWI sequences.
• MS lesions were identified across all sequences, with SWI lesions further analyzed for iron content using filtered phase images.

Main Results:

• SWI identified six distinct types of MS lesion characteristics not seen with conventional MRI.
• A significant number of lesions were exclusively detected by SWI (143) or conventional imaging (75), with 204 detected by both.
• A moderate linear correlation was found between signal intensity and iron content (phase) in SWI.

Conclusions:

• Iron deposition visualized by SWI may serve as a surrogate biomarker for diverse MS lesion characteristics.
• SWI detects numerous MS lesions and lesion characteristics overlooked by conventional MRI techniques.
• SWI demonstrates high efficacy in identifying iron within MS lesions and specific brain regions like the basal ganglia and pulvinar thalamus.