1Physiology
and Functional Genomics, University of Florida, Gainesville, FL , United
States; 2Physiology and Functional Genomics, University of
Florida, Gainesville, FL, United States; 3Physical Therapy,
University of Florida, Gainesville, FL, United States; 4Department
of Behavioral Neuroscience, Oregon Health & Science University, Portland,
OR, United States; 5Department of Physiology, University of
Pennsylvania, Philadelphia, PA, United States; 6Pediatrics, The
Children's Hospital of Philadelphia, Philadelphia, PA, United States
We used chemical-shift based MRI to quantify fatty infiltration in dystrophic muscles. We evaluated the combined influence of the model used for fat spectral decomposition, T1 variations, and signal to noise on the calculated fat fraction in Duchenne muscular dystrophy (DMD), congenital muscular dystrophy (C6), and control muscles, using localized 1H-MRS as a validation measure. Our results indicated that noise bias correction and the use of a 6-peak spectral model for fat allow good agreement between MRI and MRS measurement over a large range of fat fraction values, making chemical-shift based MRI a potential complementary quantitative measure in clinical trials.