title: Evaluation of muscles affected by myositis using magnetic resonance elastography.
abstract: BACKGROUND
  Idiopathic inflammatory myopathies (IIMs, or myositis) represent a group of autoimmune diseases that result in decreased muscle strength and/or endurance. Non-invasive tools to assess muscle may improve our understanding of the clinical and functional consequences of myopathies and their response to treatment. In this study we examine magnetic resonance elastography (MRE), a non-invasive technique that assesses the shear modulus (stiffness) of muscle, in IIM subjects.
  
  
  METHODS
  Nine subjects with active myositis completed the MRE protocol. Participants lay in a positioning device, and scans of the vastus medialis (VM) were taken in the relaxed state and at two contraction levels. Manual inversion was used to estimate the stiffness.
  
  
  RESULTS
  A significant reduction in muscle stiffness was seen in myositis subjects compared with healthy controls during the "relaxed" condition.
  
  
  CONCLUSIONS
  The use of non-invasive technologies such as MRE may provide greater understanding of the pathophysiology of IIM and improve assessment of treatment efficacy.
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, College of Medicine, 200 First Street SW, Rochester, Minnesota 55905, USA.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: McCullough
authors.forename: Zachary J
authors.initials: ZJ
authors.lastname: Domire
authors.forename: Ann M
authors.initials: AM
authors.lastname: Reed
authors.forename: Shreyasee
authors.initials: S
authors.lastname: Amin
authors.forename: Steven R
authors.initials: SR
authors.lastname: Ytterberg
authors.forename: Qingshan
authors.initials: Q
authors.lastname: Chen
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D009220:Myositis / Q000175:diagnosis* / Q000503:physiopathology*