Anticholinergic agents result in weaker and shorter suppression of uterine contractility compared with intestinal motion: time course observation with cine MRI.

PURPOSE

To evaluate the time course effects of anticholinergic agents on uterine contractility and intestinal motion with cine magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Using a 1.5 T MRI scanner, 60 T2-weighted half-Fourier rapid acquisitions with relaxation enhancement images of the uterus were serially acquired over 3 minutes in 25 healthy women in the periovulatory phase, at four instances, prior to and 2-5, 5-8, and 10-13 minutes after intravenous injection of 20 mg of hyoscine butylbromide. Uterine peristalsis frequency (waves / 3 min) and degrees of endometrial transformation, subendometrial conduction, outer myometrial conduction, sporadic myometrial contraction, and intestinal movement were independently evaluated by three readers.

RESULTS

Uterine peristalsis frequency of 6.14 ± 2.34 decreased the most at 2-5 minutes (P < 0.001) by 1.41 (95% confidential interval [CI] = 0.59-2.22), or 23.0% ([6.14-4.73]/6.14) and remained reduced at 5-8 minutes (P = 0.013) by 0.97 (95% CI = 0.15-1.78), or 15.8% ([6.14-5.17]/6.14) after injection. The degree of intestinal movement was 3.32 ± 0.54 and was prominently reduced at every phase (P < 0.001 for all) and maximally decreased to 0.67 ± 0.65 at 5-8 min. It increased to 1.36 ± 0.72 at 10-13 minutes compared with the degrees of motion at 2-5 minutes (P = 0.04) and 5-8 minutes (P = 0.004).

CONCLUSION

Suppression of uterine peristalsis was weaker and shorter compared with the stronger and longer suppression of intestinal movement by the intravenous administration of anticholinergic agents.