title: Physiological changes of the human uterine myometrium during menstrual cycle: preliminary evaluation using BOLD MR imaging.
abstract: OBJECTIVE
  To investigate the T2* values within the junctional zone and outer uterine myometrium and their changes during the menstrual cycle, and thus to evaluate their physiologic changes on blood oxygenation level-dependent (BOLD) magnetic resonance (MR) imaging.
  
  
  METHODS
  Single-shot echo-planar imaging (EPI) was used to acquire T2*-weighted images (TR/TE = 1000 msec/23-150 msec) from 15 healthy females with a 1.5-T magnet. T2* values of both junctional zone and outer uterine myometrium were measured within a single breathhold and during three menstrual cycle phases (menstrual, periovulatory, and luteal phase). Signal intensities of uterine myometrium on T2-weighted images were also evaluated.
  
  
  RESULTS
  T2* could successfully be calculated in 13 subjects. T2* values for the junctional zone were significantly lower than those of the outer myometrium at every phase(P < 0.001), and T2* values of both junctional zone (P < 0.05) and outer (P < 0.01). Myometrium in the menstrual phase was significantly lower than those in the other phases. On T2-weighted images, the signal intensity of the junctional zone was significantly lower than outer myometrium in every phase (P < 0.01), but there was no significant difference among menstrual cycle phases in both layers (P > 0.05).
  
  
  CONCLUSIONS
  This preliminary study suggested that menstrual cycle changes of the uterine myometrium were shown by BOLD imaging. BOLD MR imaging may be an potential modality to investigate physiologic changes of the uterine myometrium during the menstrual cycle.
authors.affiliation: Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan. akikido@kuhp.kyoto-u.ac.jp
authors.forename: Aki
authors.initials: A
authors.lastname: Kido
authors.forename: Takashi
authors.initials: T
authors.lastname: Koyama
authors.forename: Masako
authors.initials: M
authors.lastname: Kataoka
authors.forename: Akira
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Saga
authors.forename: Robert
authors.initials: R
authors.lastname: Turner
authors.forename: Kaori
authors.initials: K
authors.lastname: Togashi
mesh_terms: D000328:Adult; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008597:Menstrual Cycle; D009215:Myometrium / Q000033:anatomy & histology* / Q000473:pathology*; D013997:Time Factors; D014599:Uterus / Q000033:anatomy & histology / Q000473:pathology