7T MPFLAIR versus MP2RAGE for Quantifying Lesion Volume in Multiple Sclerosis

Area of Science:

• Neuroimaging
• Radiology
• Multiple Sclerosis Research

Background:

• Quantifying multiple sclerosis (MS) lesion volume using fluid-attenuated inversion recovery (FLAIR) on 7 Tesla (7T) MRI is limited by poor image homogeneity.
• Limited data exists on alternative MRI modalities for robust lesion volume measurement in MS.
• Accurate lesion quantification is crucial for tracking disease progression and treatment efficacy in MS.

Purpose of the Study:

• To evaluate magnetization-prepared 2 rapid acquisition gradient echo (MP2RAGE) as a viable alternative to FLAIR for measuring white matter lesion (WML) volume on 7T MRI.
• To assess the correlation between MP2RAGE-derived lesion volumes and clinical disability measures in patients with MS.
• To compare the robustness of MP2RAGE and FLAIR for lesion volume quantification and disability correlations in MS research.

Main Methods:

• Annual brain 7T MRIs were acquired from 47 participants with MS.
• Magnetization-prepared FLAIR (MPFLAIR) and MP2RAGE sequences were analyzed from 80 MRI scans.
• White matter lesion (WML) masks were manually created from MPFLAIR and MP2RAGE T1 maps, and lesion volumes were correlated with disability scores.

Main Results:

• Normalized WML volumes were greater with MPFLAIR compared to MP2RAGE T1 maps, but the volumes were highly correlated (rho = 0.87, P < .001).
• Both MPFLAIR and MP2RAGE T1 map-derived WML volumes showed significant correlations with most clinical disability measures.
• There was no significant difference in the strength of correlation between lesion volumes from either modality and disability measures.

Conclusions:

• 7T MPFLAIR and MP2RAGE T1 map-based WML volumes are highly intercorrelated in MS patients.
• Both modalities demonstrate significant correlations with clinical disability, indicating their utility in MS research.
• MP2RAGE represents a potentially viable alternative to FLAIR for robust WML measurement on 7T MRI in MS studies.