Ultra-low-field MRI for bedside imaging of severe multiple sclerosis

Area of Science:

• Neurology
• Medical Imaging
• Neuroscience

Background:

• Severe multiple sclerosis (MS) poses research challenges due to patient mobility and care needs.
• Portable ultra-low-field (ULF) MRI enables bedside imaging for this population, overcoming limitations of traditional MRI.
• This study investigates the utility of ULF MRI in severe MS patients.

Purpose of the Study:

• Compare ULF MRI volumetry with standard 3 Tesla (3T) MRI.
• Assess the capability of portable ULF MRI in characterizing severe MS.
• Evaluate associations between MRI findings and clinical outcomes.

Main Methods:

• Prospective study with two cohorts: healthy controls (HC) and people with MS (pwMS), and progressive MS patients (severe vs. less severe).
• Both cohorts underwent ULF MRI; Cohort 1 also had 3T MRI scans.
• Clinical assessments included disability and cognition; MRI data processed with conventional (SIENAX) and AI-driven (WMH-SynthSeg) techniques.

Main Results:

• ULF MRI and 3T MRI demonstrated significant disease differences in Cohort 1.
• WMH-SynthSeg ULF MRI showed strong effect sizes for whole brain, cortical gray matter (GM), and thalamic volumes.
• In Cohort 2, SIENAX-derived cortical GM and whole brain volumes showed largest effect sizes differentiating disease severity; WMH-SynthSeg excelled for white matter (WM) volume.

Conclusions:

• Portable ULF MRI is feasible for people with MS, including those with severe disease.
• ULF MRI offers insights into late-stage neurodegeneration in severe MS.
• MRI-clinical associations depend on processing methods, with SIENAX showing consistent correlations in severe MS.