title: Quantitative muscle MRI as an assessment tool for monitoring disease progression in LGMD2I: a multicentre longitudinal study.
abstract: BACKGROUND
  Outcome measures for clinical trials in neuromuscular diseases are typically based on physical assessments which are dependent on patient effort, combine the effort of different muscle groups, and may not be sensitive to progression over short trial periods in slow-progressing diseases. We hypothesised that quantitative fat imaging by MRI (Dixon technique) could provide more discriminating quantitative, patient-independent measurements of the progress of muscle fat replacement within individual muscle groups.
  
  
  OBJECTIVE
  To determine whether quantitative fat imaging could measure disease progression in a cohort of limb-girdle muscular dystrophy 2I (LGMD2I) patients over a 12 month period.
  
  
  METHODS
  32 adult patients (17 male;15 female) from 4 European tertiary referral centres with the homozygous c.826C>A mutation in the fukutin-related protein gene (FKRP) completed baseline and follow up measurements 12 months later. Quantitative fat imaging was performed and muscle fat fraction change was compared with (i) muscle strength and function assessed using standardized physical tests and (ii) standard T1-weighted MRI graded on a 6 point scale.
  
  
  RESULTS
  There was a significant increase in muscle fat fraction in 9 of the 14 muscles analyzed using the quantitative MRI technique from baseline to 12 months follow up. Changes were not seen in the conventional longitudinal physical assessments or in qualitative scoring of the T₁w images.
  
  
  CONCLUSIONS
  Quantitative muscle MRI, using the Dixon technique, could be used as an important longitudinal outcome measure to assess muscle pathology and monitor therapeutic efficacy in patients with LGMD2I.
authors: Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.
authors: Tracey A
authors: TA
authors: Willis
authors: Kieren G
authors: KG
authors: Hollingsworth
authors: Anna
authors: A
authors: Coombs
authors: Marie-Louise
authors: ML
authors: Sveen
authors: Søren
authors: S
authors: Andersen
authors: Tanya
authors: T
authors: Stojkovic
authors: Michelle
authors: M
authors: Eagle
authors: Anna
authors: A
authors: Mayhew
authors: Paulo L
authors: PL
authors: de Sousa
authors: Liz
authors: L
authors: Dewar
authors: Jasper M
authors: JM
authors: Morrow
authors: Christopher D J
authors: CD
authors: Sinclair
authors: John S
authors: JS
authors: Thornton
authors: Kate
authors: K
authors: Bushby
authors: Hanns
authors: H
authors: Lochmüller
authors: Michael G
authors: MG
authors: Hanna
authors: Jean-Yves
authors: JY
authors: Hogrel
authors: Pierre G
authors: PG
authors: Carlier
authors: John
authors: J
authors: Vissing
authors: Volker
authors: V
authors: Straub
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000473:pathology*; D049288:Muscular Dystrophies, Limb-Girdle / Q000175:diagnosis* / Q000473:pathology*; D055815:Young Adult
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