title: Thigh muscle stiffness assessed with magnetic resonance elastography in hyperthyroid patients before and after medical treatment.
abstract: OBJECTIVE
  To measure the stiffness of the vastus medialis (VM) in hyperthyroid patients before and after treatment.
  
  
  METHODS
  A total of five healthy euthyroid patients and five hyperthyroid patients were tested using magnetic resonance elastography (MRE), which involves the induction of shear waves in the thigh muscles using a pneumatic driver at 90 Hz.
  
  
  RESULTS
  Among the pretreatment hyperthyroid cohort a lower stiffness was found when the muscle was relaxed (2.11 +/- 0.61 kPa) compared the stiffness following treatment of hyperthyroidism (5.52 +/- 1.52 kPa), which was accompanied by an improvement in the contractile function of the VM. Pretreatment muscle stiffness was also less than that of age matched healthy volunteers (4.56 +/- 0.40 kPa). The behavior of the waves was sensitive to the stage of this myopathy and to the amount of free thyroxine (FT4).
  
  
  CONCLUSIONS
  The MRE technique provides a new tool to gain new insights into pathophysiology of thyroid associated and other muscle diseases and their response to treatment.
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, College of Medicine, Rochester, Minnesota, USA.
authors.forename: Sabine F
authors.initials: SF
authors.lastname: Bensamoun
authors.forename: Stacie I
authors.initials: SI
authors.lastname: Ringleb
authors.forename: Qingshan
authors.initials: Q
authors.lastname: Chen
authors.forename: Richard L
authors.initials: RL
authors.lastname: Ehman
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
authors.forename: Michael
authors.initials: M
authors.lastname: Brennan
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D017352:Echo-Planar Imaging / Q000379:methods; D004548:Elasticity; D005260:Female; D006111:Graves Disease / Q000473:pathology; D006801:Humans; D006980:Hyperthyroidism / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000473:pathology*; D052097:Quadriceps Muscle / Q000473:pathology*; D013848:Thigh / Q000473:pathology*; D013974:Thyroxine / Q000627:therapeutic use
chemical_list: D013974:Thyroxine