Using quantitative magnetic resonance imaging to track cerebral alterations in multiple sclerosis brain: A...

Area of Science:

• Neuroimaging
• Quantitative Magnetic Resonance Imaging (qMRI)
• Neurodegenerative Diseases

Background:

• Quantitative MRI (qMRI) offers insights into tissue microstructural properties, crucial for characterizing cerebral damage.
• Multi-parameter mapping (MPM) in qMRI generates parameter maps (MTsat, PD, R1, R2*) reflecting iron and myelin content.
• qMRI is a promising tool for in vivo monitoring of cerebral damage and repair in Multiple Sclerosis (MS).

Purpose of the Study:

• To investigate longitudinal microstructural changes in the brain of MS patients using qMRI.
• To correlate qMRI parameter evolution with clinical status and disease progression in MS.
• To assess the utility of qMRI in monitoring subtle changes in normal-appearing brain tissues and focal lesions.

Main Methods:

• Seventeen MS patients underwent 3T MRI scans at two time points, separated by a median of 30 months.
• qMRI parameter evolution (MTsat, PD, R1, R2*) was analyzed in normal-appearing white matter (NAWM), normal-appearing gray matter (NACGM), and white matter (WM) lesions.
• Longitudinal changes were quantified as annual rates, and statistical models (GLMM) were used to analyze parameter variations.

Main Results:

• Patients with better clinical outcomes exhibited positive annual changes in MTsat and R2* within NAWM and NACGM, suggesting myelin repair and edema resorption.
• Microstructural modifications were detected in NAWM surrounding WM lesions, preceding their visibility on conventional FLAIR MRI.
• qMRI parameters demonstrated sensitivity to subtle, longitudinal microstructural changes in MS brains.

Conclusions:

• Multiple qMRI parameters effectively monitor subtle changes in normal-appearing brain tissues and plaque dynamics in MS.
• qMRI data correlate with tissue repair mechanisms and disease progression, offering valuable insights beyond conventional imaging.
• This study highlights the potential of qMRI for longitudinal monitoring of MS, aiding in the understanding of disease mechanisms and therapeutic responses.