Multi-parametric quantitative MRI of the lower limb muscles in a longitudinal study of limb-girdle muscular dystrophy R9

Motivation: Quantitative MRI (qMRI) holds potential as biomarker to monitor disease progression in limb-girdle muscular dystrophy R9 (LGMD-R9). Goal(s): We investigated qMRI to differentiate between healthy and diseased muscles and explored its ability to predict disease progression in LGMD-R9. Approach: 18 LGMD-R9 patients and 13 controls underwent qMRI of the lower limbs. LGMD-R9 subjects were followed-up after 1 and 2-years. Fat fraction (FF), water-T2, water-T1, diffusion tensor imaging (DTI), and pH were assessed. Results: FF, water-T2, water-T1, and pH differed significantly between LGMD-R9 and controls. Baseline-water-T2 and -water-T1 correlated with the increase in FF over 2 years, suggesting their potential to predict disease progression. Impact: QMRI parameters in LGMD-R9 patients were significantly different from controls, with water-T2 and water-T1 correlating with the increase in FF. These findings may be valuable for identifying biomarkers in clinical trials or selecting eligible LGMD-R9 patients for therapeutic treatment studies.