title: Magnetic resonance imaging in Duchenne muscular dystrophy: longitudinal assessment of natural history over 18 months.
abstract: BACKGROUND
  In Duchenne muscular dystrophy (DMD), fat replacement of muscle may be a useful endpoint in trials of therapy, although progression in different muscle groups is uneven. In this study we assessed the progression of fat replacement with T(1) -weighted imaging over 2 9-month periods.
  
  
  METHODS
  Eight ambulant, corticosteroid-treated boys with DMD were imaged at 3 Tesla at 3 time-points (baseline and 9 and 18 months) with T(1) -weighted imaging to measure fat replacement.
  
  
  RESULTS
  The greatest increase in fat content was measured in the biceps femoris long head, vastus lateralis, and rectus femoris, whereas the biceps femoris short head and gluteus maximus progressed more slowly. None of the lower leg muscles studied changed significantly.
  
  
  CONCLUSIONS
  MRI can measure specific changes in fat replacement of muscle over time, demonstrating the variability in rates of natural progression between muscle groups and identifying those muscles suitable for use as biomarkers in clinical trials.
authors.affiliation: Newcastle Magnetic Resonance Centre, Institute of Cellular Medicine, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE4 5PL, UK.
authors.forename: Kieren G
authors.initials: KG
authors.lastname: Hollingsworth
authors.forename: Penny
authors.initials: P
authors.lastname: Garrood
authors.forename: Michelle
authors.initials: M
authors.lastname: Eagle
authors.forename: Kate
authors.initials: K
authors.lastname: Bushby
authors.forename: Volker
authors.initials: V
authors.lastname: Straub
mesh_terms: D000273:Adipose Tissue / Q000503:physiopathology; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D002648:Child; D018450:Disease Progression; D006801:Humans; D008137:Longitudinal Studies; D035002:Lower Extremity / Q000503:physiopathology; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D018482:Muscle, Skeletal / Q000503:physiopathology*; D020388:Muscular Dystrophy, Duchenne / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D013997:Time Factors
chemical_list: D000305:Adrenal Cortex Hormones
keywords: Duchenne muscular dystrophy; MRI; corticosteroids; fat replacement; longitudinal