title: Changes of the normal ovary during menstrual cycle in reproductive age on the diffusion-weighted image.
abstract: OBJECTIVE
  The objective of this study was to investigate changes in magnetic resonance findings of the normal ovary during menstrual cycle on diffusion-weighted image (DWI).
  
  
  METHODS
  Magnetic resonance imaging was performed in 9 healthy females at the menstrual, periovulatory, and luteal phases using a 1.5-T unit. Signal intensity (SI) of the ovary on DWI with a b value of 1000 s/mm was visually scored. The ovary-to-muscle contrast ratios on DWI and apparent diffusion coefficient (ADC) values were also evaluated.
  
  
  RESULTS
  All the ovaries were identified, and higher SI than the nerve root was identified in 70% (38/54) of the ovaries, although visual scores did not show significant difference among menstrual phases. The mean ADC values (10 mm/s) were 1.71 (SD, 0.27), 1.71 (SD, 0.22), and 1.67 (SD, 0.19) in menstrual, periovulatory, and luteal phases, respectively. No phase-dependent change was observed in contrast ratios and ADC values.
  
  
  CONCLUSIONS
  The normal ovary in fertile period shows high SI enough to be identified on DWI, and observed values are independent of the menstrual cycle.
authors.affiliation: Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Japan. nobuko@kuhp.kyoto-u.ac.jp
authors.forename: Nobuko
authors.initials: N
authors.lastname: Morisawa
authors.forename: Aki
authors.initials: A
authors.lastname: Kido
authors.forename: Takashi
authors.initials: T
authors.lastname: Koyama
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Okada
authors.forename: Masako
authors.initials: M
authors.lastname: Kataoka
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Umeoka
authors.forename: Koji
authors.initials: K
authors.lastname: Fujimoto
authors.forename: Ken
authors.initials: K
authors.lastname: Tamai
authors.forename: Kaori
authors.initials: K
authors.lastname: Togashi
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008597:Menstrual Cycle; D015588:Observer Variation; D010053:Ovary / Q000033:anatomy & histology*; D011446:Prospective Studies; D012016:Reference Values; D055815:Young Adult