Short T2 Fraction Mapping of Skeletal Muscle Integrating Ultralow TE (UTE) and MP-IDEAL multiecho data

Ultralow TE imaging of skeletal muscle enables the visualization of low T2* species. In skeletal muscle, the signal from the small fraction of short-T2 (T2^S) components are masked by the larger component long-T2 (T2^L) species. One method is to extract the short T2 components from subtracted images of a dual echo UTE sequence. However, the subtracted images invariably have residual signal from lipids due to the chemically shifted frequencies of signals produced by lipids. We integrate the fat fraction and T2^L extracted from MP-IDEAL sequence to the subtracted UTE images to extract the fibrosis fraction.