William Rooney1, Sean Forbes2, James Pollaro1, Dah-Jyuu Wang3, Soren de Vos2, William Triplett4, James Meyer3, Rachel Willcocks4, Barry Byrne5, Richard Finkel6, Barry Russman7, Lee Sweeney8, Glenn Walter4, Krista Vandenborne2
1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States; 2Department of Physical Therapy, University of Florida, Gainesville, FL, United States; 3Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, United States; 4Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States; 5Pediatrics, University of Florida, Gainesville, FL, United States; 6Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, United States; 7Shriners Hospital, Portland, OR, United States; 8Department of Physiology, University of Pennsylvania, Philadelphia, PA, United States
The purpose of the study was 1) to investigate the influence of muscle lipid content on MRI determined qT2 values, and 2) to independently assess the behavior of MRS determined 1H2O qT2 values in DMD as a function of muscle lipid content. 3T MRI data were acquired from 30 DMD boys and 8 healthy controls at three institutions. Non-fat suppressed MRI determined qT2 values of the soleus increase quadratically with muscle lipid content. Soleus 1H2O T2 values are elevated in DMD before lipid content is significantly increased, which may reflect a combination of inflammation, increased sarcolemmal water permeability, and myofiber degeneration. Lipid content increases with DMD progression and we find a significant negative association between soleus 1H2O T2 and lipid fraction in DMD, perhaps associated with fibrosis.