Oral contraceptives and uterine peristalsis: evaluation with MRI.
OBJECTIVE
To evaluate the effects of oral contraceptives (OCs) on uterine contractility using cine MRI, and correlate the kinematic findings with the static findings.


METHODS
Healthy female volunteers of reproductive age (23 taking OCs, and 15 not) were evaluated at mid-cycle. MR images were obtained with a 1.5T magnet, with 60 serial images taken every three seconds by half-Fourier acquisition single-shot turbo spin echo (HASTE) to be displayed in cine mode. Assessments were based on the 1) detectability of uterine peristalsis in cine mode, 2) peristaltic frequency and direction, 3) thickness of the endometrium, myometrium, and junctional zone (JZ) on T2-weighted images (T2WIs), and 4) intensity of the myometrium and cervical mucus on T2WIs and T1-weighted images (T1WIs), respectively.


RESULTS
Uterine peristalsis was markedly decreased in the OC users. The endometrium and JZ were significantly thinner, and the myometrium was thicker in the OC users compared to controls. The signal intensity of the myometrium and cervical mucus was significantly higher in the OC users than in controls.


CONCLUSIONS
OCs markedly suppressed uterine peristalsis at mid-cycle, and the uterus displayed a globular configuration with a thin JZ that may be related to decreased uterine peristalsis in OC users.
Kido
Aki
A
Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan. akikido@kuhp.kyoto-u.ac.jp
Togashi
Kaori
K
Nakai
Asako
A
Kataoka
Milliam L
ML
Koyama
Takashi
T
Fujii
Shingo
S
D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D003276:Contraceptives, Oral / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008597:Menstrual Cycle / Q000502:physiology; D008875:Middle Aged; D011336:Probability; D012016:Reference Values; D012680:Sensitivity and Specificity; D014590:Uterine Contraction / Q000187:drug effects* / Q000502:physiology*; D014599:Uterus / Q000187:drug effects / Q000502:physiology
D003276:Contraceptives, Oral