Rapid quantification of global brain volumetry and relaxometry in patients with multiple sclerosis using synthetic magnetic resonance imaging.

Abstract

Early pathologic studies have reported that focal areas of gray lesions in the cortex and other gray matter (GM) regions are important in multiple sclerosis (MS) patients. Quantitative magnetic resonance imaging (qMRI) can provide more specific insight into the disease process, progression, and therapeutic response of MS. The purpose of this study was to quantitatively assess the changes of global GM volumetry and relaxometry information simultaneously in MS patients using synthetic MRI. All MS patients and healthy controls (HCs) were recruited. The Expanded Disability Status Scale (EDSS) scores were obtained from all patients to evaluate the disability progression. Volumetry and relaxometry of the global brain and regional GM were obtained. The quantitative parameters between MS patients and HCs were compared using an analysis of covariance (ANCOVA). The Pearson correlation assessed the correlations between the quantitative parameters and EDSS, illness duration, education in MS patients. Thirty-five MS patients and fifty-two age-matched HCs were enrolled in this prospective case-control study. The global volumetry including white matter volume (WMV), myelin volume (MYV), and brain parenchymal volume (BPV) were all significantly lower in MS patients (WMV: 613.120±65.388 vs. 579.903±68.432 mL; MYV: 151.883±22.766 vs. 192.457±27.381 mL; BPV: 1,136.771±106.126 vs. 1,276.712±107.368 mL), as well as a higher cerebral spinal fluid volume (CSFV) (241.294±81.805 vs. 177.017±39.729 mL) in MS patients than those in HCs. Similarly, brain parenchymal fraction (BPF) and myelin fraction (MYF) were significantly lower in MS patients (BPF: 82.623±5.368 vs. 87.85±2.392 mL; MYF: 11.034±1.529 vs. 13.231±1.465 mL). For regional GM volumetry, multiple regions of MS patients were significantly smaller than those of HCs (P<0.01, corrected). For regional GM relaxometry, the T1, T2, and PD values of multiple regions showed significant differences. These findings suggest that MS patients had global and regional brain volumetry and relaxometry alterations, and the synthetic MRI-derived parameters may be potentially used as specific quantitative markers for the clinic to improve the understanding of MS.