Microstructure and muscle strength in older adults: a time-dependent diffusion study

Motivation: Treatments exist to help prevent the development of sarcopenia and muscle atrophy in older adults, but the detection of early signs of atrophy is challenging. DTI can detect features of muscle atrophy associated with decrease force production, but it has low specificity. Goal(s): Our goal was to determine if time-dependent diffusion with RPBM modeling can increase the specificity to muscle fiber atrophy. Approach: Data collected from older adults at multiple mixing times were fit with RPBM and the apparent diameter a was determined. Results: RPBM-derived a has better performance at describing microstructural features related to force production, compared to conventional DTI. Impact: The apparent diameter a, obtained by modeling time-dependent diffusion data combined with RPBM modeling, is strongly associated to muscle strength in older adults, and is therefore a promising tool to study early signs of muscle atrophy and sarcopenia.