Water specific T1 in Skeletal Muscle: Validation, Normative Values and the Confounding Influence of Fat

Motivation: There is a need for water-specific T1 (T1Water) and fat quantification methods for detection of skeletal muscle fibrosis and fat infiltration. Goal(s): Illustrate a saturation recovery chemical-shift encoded (SR-CSE) T1 mapping approach for skeletal muscle T1Water and fat content quantification (validation, reproducibility and normative values across sex and age). Approach: SR-CSE scans were acquired in healthy adults (n=130) with spectroscopy validation studies and comparison to conventional T1 mapping methods. Results: SR-CSE has excellent accuracy and reproducibility. Normative values (T1Water, Inter/Intramuscular fat and muscle volumes) were established (2.89T). Conventional T1 mapping methods have a significant T1 bias from intramuscular fat. Impact: The SR-CSE approach jointly quantifies skeletal muscle fat and water-specific T1 (T1Water, removing T1 bias from fat), offering detection of muscle fibrosis and/or edema with co-existing fatty infiltration (e.g. sarcopenia).