Multi-parametric ageing study on 51 subjects in the lower leg by 1H water T1 MR fingerprinting, multi-compartment water T2, fat fraction and 31P MRS

Aging is a multi-factorial process and studies in the lower leg are scarce. We performed a multi-contrast protocol in 51 volunteers from 20 to 81 y.o. We found an age-related increase of muscle water T1(water-fat separation,MR fingerprinting), fat fraction, water T2 and T2 heterogeneity in the anterior and posterior compartments. Phosphodiesters and mitochondrial stress biomarkers also increased with age. Through bi-compartment water T2 CPMG measures, age-related increases of the long water T2 relative fraction were observed relative to the short water T2 (T2-H2O-CPMG-short) fraction, but T2-H2O-CPMG-short values were unaltered with age, suggesting inflammation with preservation of the intracellular water compartment.