Noninvasive Imaging of 4D Electrical Activation Patterns of Uterine Peristalsis During Normal Menstrual Cycles

Uterine peristalsis, characterized by spontaneous slow-wave contractions of the subendometrial layer of the uterine myometrium, occurs throughout the menstrual cycle. Disruptions in peristalsis patterns may occur in women experiencing abnormal uterine bleeding, endometriosis, and infertility. Current tools to measure uterine peristalsis in humans have limitations that hamper their research or clinical utility. Here, we developed an electrophysiological imaging system with wearable electrical sensors to noninvasively quantify the four-dimensional electrical activation pattern during human uterine peristalsis with high spatial and temporal resolution and coverage. To demonstrate capabilities of this new imaging system, we enrolled 26 pre-menopausal participants ages 18–40 years old with regular menstrual cycles (25–34 days in length) and normal gynecologic anatomy. Participants initially underwent magnetic resonance imaging to obtain the body-uterus geometry. Then, during each of the four phases of a single menstrual cycle, patients underwent noninvasive electrical recording for 30 min. We measured uterine peristalsis frequency, direction, duration, magnitude, and power and found that these parameters differed in different phases of the menstrual cycle. Future use of this uterine peristalsis imaging system may advance our understanding of the role of uterine peristalsis in maintaining normal uterine function and contributing to gynecological pathophysiology.