title: Magnetic resonance imaging and spectroscopy assessment of lower extremity skeletal muscles in boys with Duchenne muscular dystrophy: a multicenter cross sectional study.
abstract: BACKGROUND
  Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder that results in functional deficits. However, these functional declines are often not able to be quantified in clinical trials for DMD until after age 7. In this study, we hypothesized that (1)H2O T2 derived using (1)H-MRS and MRI-T2 will be sensitive to muscle involvement at a young age (5-7 years) consistent with increased inflammation and muscle damage in a large cohort of DMD subjects compared to controls.
  
  
  METHODS
  MR data were acquired from 123 boys with DMD (ages 5-14 years; mean 8.6 SD 2.2 years) and 31 healthy controls (age 9.7 SD 2.3 years) using 3-Tesla MRI instruments at three institutions (University of Florida, Oregon Health & Science University, and Children's Hospital of Philadelphia). T2-weighted multi-slice spin echo (SE) axial images and single voxel 1H-MRS were acquired from the lower leg and thigh to measure lipid fraction and (1)H2O T2.
  
  
  RESULTS
  MRI-T2, (1)H2O T2, and lipid fraction were greater (p<0.05) in DMD compared to controls. In the youngest age group, DMD values were different (p<0.05) than controls for the soleus MRI-T2, (1)H2O T2 and lipid fraction and vastus lateralis MRI-T2 and (1)H2O T2. In the boys with DMD, MRI-T2 and lipid fraction were greater (p<0.05) in the oldest age group (11-14 years) than the youngest age group (5-6.9 years), while 1H2O T2 was lower in the oldest age group compared to the young age group.
  
  
  CONCLUSIONS
  Overall, MR measures of T2 and lipid fraction revealed differences between DMD and Controls. Furthermore, MRI-T2 was greater in the older age group compared to the young age group, which was associated with higher lipid fractions. Overall, MR measures of T2 and lipid fraction show excellent sensitivity to DMD disease pathologies and potential therapeutic interventions in DMD, even in the younger boys.
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
authors.forename: Sean C
authors.initials: SC
authors.lastname: Forbes
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Willcocks
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
authors.forename: William T
authors.initials: WT
authors.lastname: Triplett
authors.affiliation: Oregon Health & Science University, Portland, OR, United States of America.
authors.forename: William D
authors.initials: WD
authors.lastname: Rooney
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
authors.forename: Donovan J
authors.initials: DJ
authors.lastname: Lott
authors.affiliation: The Children's Hospital of Philadelphia, Philadelphia, PA, United States of America.
authors.forename: Dah-Jyuu
authors.initials: DJ
authors.lastname: Wang
authors.affiliation: Oregon Health & Science University, Portland, OR, United States of America.
authors.forename: Jim
authors.initials: J
authors.lastname: Pollaro
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
authors.forename: Claudia R
authors.initials: CR
authors.lastname: Senesac
authors.affiliation: Department of Statistics & Data Sciences and Department of Integrative Biology, the University of Texas at Austin, Austin, TX, United States of America.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Daniels
authors.affiliation: The Children's Hospital of Philadelphia, Philadelphia, PA, United States of America; Nemours Children's Hospital, Orlando, Florida, United States of America.
authors.forename: Richard S
authors.initials: RS
authors.lastname: Finkel
authors.affiliation: Oregon Health & Science University, Portland, OR, United States of America.
authors.forename: Barry S
authors.initials: BS
authors.lastname: Russman
authors.affiliation: Department of Pediatrics and Molecular Genetics & Microbiology, Powell Gene Therapy Center, University of Florida, Gainesville, FL, United States of America.
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Byrne
authors.affiliation: Oregon Health & Science University, Portland, OR, United States of America.
authors.forename: Erika L
authors.initials: EL
authors.lastname: Finanger
authors.affiliation: The Children's Hospital of Philadelphia, Philadelphia, PA, United States of America.
authors.forename: Gihan I
authors.initials: GI
authors.lastname: Tennekoon
authors.affiliation: Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States of America.
authors.forename: Glenn A
authors.initials: GA
authors.lastname: Walter
authors.affiliation: Department of Physiology, University of Pennsylvania, Philadelphia, PA, United States of America.
authors.forename: H Lee
authors.initials: HL
authors.lastname: Sweeney
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
authors.forename: Krista
authors.initials: K
authors.lastname: Vandenborne
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D018450:Disease Progression; D006801:Humans; D007866:Leg; D050356:Lipid Metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D020388:Muscular Dystrophy, Duchenne / Q000378:metabolism*