A new method for analysis of non-pregnant uterine peristalsis using transvaginal ultrasound

Objectives To develop an objective method for analysis of uterine peristalsis using transvaginal sonography (TVS). Methods We performed computerized analysis of 2-5-min video recordings of TVS imaging of a midsagittal cross-section of the uterus during the proliferative and early secretory phases of 18 healthy volunteers aged 28-41 years. The contours of the fluid-endometrial interface (FEI) and the endometrium-myometrium interface (EMI) were detected in each frame, and the data from all frames were used to explore the dynamic motility characteristics of these interfaces at fixed distances from the fundus. Results The mean ± SD dominant frequency of peristalsis of the EMI along the midsagittal cross-section was 0.049 ± 0.01 Hz and that of the cavity center was 0.043 ± 0.02 Hz. The maximal amplitudes of the EMI were about 1 ± 0.25 mm, located between 7 and 17 mm from the fundus. The amplitudes of the FEI were in the range 0.05-0.2 mm. The amplitude of the cavity centerline movement was 0.94 ± 0.34 mm, located at the extremes of the unperturbed curve. Conclusions This study provides a simple tool for analysis of uterine peristalsis characteristics using ultrasound data. This is possible at the EMI even when the FEI is invisible or incomplete, such as during the luteal phase, when an intrauterine contraceptive device is in place, and during diagnostic or medical intervention.