OC22.04: Ultrasound‐based Strain Mapping for Contraction Frequency in the Non‐pregnant Uterus

It has been postulated that increased uterine peristalsis (UP) negatively influences in vitro fertilisation outcome due to endometrial hyper-contractility after embryo transfer. An objective and non-invasive characterisation of UP can therefore provide an important contribution to many clinical procedures. In this study, strain mapping based on optical flow is applied on two-dimensional (2D) transvaginal ultrasound (TVUS) videos to quantify UP outside pregnancy. Eight healthy women, with a natural regular cycle, underwent 4-minute TVUS during the menses (M), late follicular (LF), early luteal (EL) and late luteal (LL) phase of the cycle. Strain mapping based on optical flow was applied to calculate and visualise strain variations. The obtained strain maps were rendered with suitable colour maps; red for relaxation (negative strain) and blue for contraction (positive strain). Statistical analysis based on Kruskal–Wallis test and Dunn's test were applied to evaluate the differences in contraction frequency between the phases. 2D-strain maps were created for all phases in transversal direction (figure1). Statistical analysis showed significant differences in contraction frequency between M-LF (P=0.002), M-EL (P=0.003), LF-LL (P=0.034) and EL-LL (P=0.048) phase. The results show that we can accurately strain-map the non-pregnant uterus, and that we can objectively classify contraction frequency in different phases of the menstrual cycle. Future work will focus on three-dimensional strain analysis to provide more accurate results in multiple directions. Supporting information can be found in the online version of this abstract Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.