title: Effect of passive muscle length change on apparent diffusion coefficient: detection with clinical MR imaging.
abstract: OBJECTIVE
  We investigated whether change in muscle microstructure associated with passive extension and contraction affects proton diffusivity.
  
  
  METHODS
  In 6 male subjects, we compared apparent diffusion coefficients (ADC) along the posterior-to-anterior (ADC-PA), right-to-left (ADC-RL) and superior-to-inferior (ADC-SI) directions of the right tibialis anterior muscle with the ankle joint in passive plantar flexion and passive dorsiflexion.
  
  
  RESULTS
  Compared to the respective ADCs at plantar flexion, the ADC-PA (P=0.002) and ADC-RL (P=0.008) were significantly greater, but ADC-SI (P=0.008) significantly lower at dorsiflexion.
  
  
  CONCLUSIONS
  Our results indicate that change in muscle microstructure associated with passive extension and contraction would affect proton diffusivity, and this alteration of proton diffusivity could be detected by measuring ADC with a clinical magnetic resonance scanner.
authors.affiliation: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Radiology Center, Kyushu University Hospital, Fukuoka, Japan. mhatake@radiol.med.kyushu-u.ac.jp
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Hatakenaka
authors.forename: Hidetake
authors.initials: H
authors.lastname: Yabuuchi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Matsuo
authors.forename: Takashi
authors.initials: T
authors.lastname: Okafuji
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kamitani
authors.forename: Taro
authors.initials: T
authors.lastname: Setoguchi
authors.forename: Kei
authors.initials: K
authors.lastname: Nishikawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Honda
mesh_terms: D000328:Adult; D001834:Body Water / Q000737:chemistry* / Q000502:physiology*; D004058:Diffusion; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000737:chemistry* / Q000502:physiology*