title: Investigation of uterine peristalsis diurnal variation.
abstract: BACKGROUND
  In women of reproductive age, wavelike movements of the subendometrial myometrium, which is called uterine peristalsis, is considered to be related with fertility and menstrual problems. This is because the direction and frequency of peristalsis is known to be different among menstrual cycle phases. However, nothing is known as regarding diurnal variations. This study was designed to evaluate for the presence of a diurnal variation in uterine peristalsis.
  
  
  METHODS
  MR studies were performed on 12 volunteers of reproductive age using a 1.5-T magnet, four times per day (at 0800, 1300, 1800 and 2300 h) during three (periovulatory, luteal and menstrual) phases of one menstrual cycle. Sixty images were obtained by half-Fourier acquisition single-shot turbo spin echo every 2 s and displayed on cine mode. Semiautomated software was utilized to discern the presence of peristaltic waves, as well as peristaltic frequency and direction. The presence of sustained contractions was visually determined.
  
  
  RESULTS
  There was no statistically significant difference during the daytime for frequency and direction of uterine peristalsis for all menstrual cycle phases. Nonetheless, peristaltic frequency and direction fluctuated during each cycle. Statistically significant peristaltic suppression was observed in association with sustained contractions during the periovulatory phase.
  
  
  CONCLUSIONS
  A diurnal variation was not observed for uterine peristalsis. Sporadic changes in peristaltic frequency were observed and appear to be closely related to sustained uterine contractions.
authors.affiliation: Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan. akikido@kuhp.kyoto-u.ac.jp
authors.forename: Aki
authors.initials: A
authors.lastname: Kido
authors.forename: Kaori
authors.initials: K
authors.lastname: Togashi
authors.forename: Asako
authors.initials: A
authors.lastname: Nakai
authors.forename: Masako
authors.initials: M
authors.lastname: Kataoka
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Fujiwara
authors.forename: Milliam Lika
authors.initials: ML
authors.lastname: Kataoka
authors.forename: Ryota
authors.initials: R
authors.lastname: Fujimoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Koyama
authors.forename: Shingo
authors.initials: S
authors.lastname: Fujii
mesh_terms: D000328:Adult; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008597:Menstrual Cycle / Q000502:physiology*; D010528:Peristalsis / Q000502:physiology*; D014590:Uterine Contraction / Q000502:physiology*; D014599:Uterus / Q000502:physiology