title: Evaluation of extraocular muscles using dynamic contrast enhanced MRI in patients with chronic thyroid orbitopathy.
abstract: OBJECTIVE
  The purpose of the current study is to investigate the underlying pathophysiological changes of extraocular muscle (EOM) in Graves orbitopathy using dynamic contrast MR imaging and to correlate these MR functional changes with the anatomic abnormalities.
  
  
  METHODS
  EOMs of 16 patients with Graves disease and 12 normal volunteers were examined by dynamic enhanced MRI. We quantified the peak enhancement ratio of EOMs and calculated the ratio versus temporalis muscle and the ratio of maximum upslope versus temporalis muscle. We compared the ratios between normal volunteers and patient groups.
  
  
  RESULTS
  Mean of peak enhancement ratio values for the EOMs in patients with Graves disease tends to decrease according to the severity of the anatomic and clinical changes. The mean maximum upslope also decreased according to the severity of the disease for EOMs.
  
  
  CONCLUSIONS
  Hemodynamic information obtained by dynamic contrast enhanced MRI is useful in evaluating the clinical course of thyroid orbitopathy.
authors.affiliation: Department of Radiology, Nara Medical University, Nara, Japan. ttoaka@naramed-u.ac.jp
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Taoka
authors.forename: Masahiko
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakagawa
authors.forename: Akio
authors.initials: A
authors.lastname: Fukusumi
authors.forename: Satoru
authors.initials: S
authors.lastname: Iwasaki
authors.forename: Keiko
authors.initials: K
authors.lastname: Taoka
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Kichikawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D003287:Contrast Media; D005094:Exophthalmos / Q000503:physiopathology; D019786:Gadolinium DTPA; D006111:Graves Disease / Q000503:physiopathology*; D006801:Humans; D006984:Hypertrophy; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000503:physiopathology*; D012680:Sensitivity and Specificity; D013703:Temporal Muscle / Q000503:physiopathology; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D013997:Time Factors
chemical_list: D003287:Contrast Media; D013972:Thyrotropin; D019786:Gadolinium DTPA; D013974:Thyroxine