Inversion Recovery Susceptibility Weighted Imaging With Enhanced T2 Weighting at 3 T Improves Visualization of Subpial Cortical Multiple Sclerosis Lesions

Abstract

Objectives: Cortical demyelination is common in multiple sclerosis (MS) and can be extensive. Cortical lesions contribute to disability independently from white matter lesions and may form via a distinct mechanism. However, current magnetic resonance imaging (MRI) methods at 3 tesla (3T) are insensitive to cortical, and especially subpial cortical, lesions. Subpial lesions are wellseen on T 2 * weighted imaging at 7 tesla (7T), but T 2 * weighted methods on 3T scanners are limited by poor lesion-to-cortex and cerebrospinal fluid (CSF)-to-lesion contrast. We aimed to develop and evaluate a CSF-suppressed, T 2 *-weighted sequence optimized for subpial cortical lesion visualization. Materials and methods:We developed a new MRI sequence, Inversion Recovery Susceptibility Weighted Imaging with Enhanced T 2 -Weighting (IR-SWIET, 0.8mm x 0.8mm in plane, 0.64mm slice thickness with whole brain coverage, acquisition time ~5 min). We compared cortical lesion visualization independently on IR-SWIET (median signal from four acquisitions),

Age-Related Changes in Relaxation Times, Proton Density, Myelin, and Tissue Volumes in Adult Brain Analyzed by 2-Dimensional Quantitative Synthetic Magnetic Resonance Imaging

“… 77 Regarding future perspectives, comparison of quantitative synthetic MRI with other sequences sensitive to cortical lesion detection would be interesting. 78 , 79 Further, multiparametric quantitative information acquired with quantitative synthetic MRI may improve the prediction of contrast enhancement and the quality of automatic lesion segmentation, as were previously performed by using contrast-weighted images. 80 , 81 …”

Ex vivo MR microscopy of a human brain with multiple sclerosis: Visualizing individual cells in tissue using intrinsic iron

“…Such a sequence has now been validated in MS and healthy volunteers at 3T in our lab, and comparison with other sequences for imaging cortical lesions in MS on the 3T and 7T clinical scanners performed. ( Beck et al, 2020 )…”

New Prospects for Ultra-High-Field Magnetic Resonance Imaging in Multiple Sclerosis

“… 17 In a study with 26 MS patients, 7-T FLASH T2*w was more accurate at detecting particularly subpial lesions compared with 3-T DIR and magnetization-prepared rapid acquisition with gradient echo (MPRAGE). 82 Inversion recovery susceptibility-weighted imaging with enhanced T2 weighting is a T2*w sequence with suppressed CSF signal, which allows for improved detection of subpial lesions at 3 T, 86 but it has not yet been investigated at 7 T. Of note, a study comparing MP2RAGE and T2*w images at 7 T can show higher sensitivity of MP2RAGE to detect cortical lesions, albeit some lesions were only seen on T2*w images. 87 Because subpial lesions have been proposed as a pathognomonic feature of MS, classification of cortical lesions is particularly important to improve specificity of MRI for MS diagnosis.…”