Quantitative Motion Analysis Of The Uterus By Optical Flow And Two-dimensional Strain Mapping

Successful in-vitro fertilization is achieved in 30% of the procedures only. Implantation failure may be caused by uterine peristalsis. Therefore, the in-vitro fertilization success rate may be improved by novel methods enabling objective and non-invasive characterization of uterine peristalsis. In this study, strain mapping based on speckle tracking is applied on two-dimensional transvaginal ultrasound recordings to quantify UP outside pregnancy. Eight healthy women, with a natural regular cycle, underwent 4-minute transvaginal ultrasound scans during the late follicular and late luteal phase, suggested to be the most active and the most quiet phase of the menstrual cycle, respectively. For each ultrasound recording, a region of interest was chosen to include the junctional zone close to the fundus, where the strongest uterine peristalsis can be found based on clinical evidence. A grid of markers was defined inside the region of interest so that strain and strain rate could be calculated from the relative movement of the adjacent markers acquired by speckle tracking. Color rendered techniques, such as color coding and interpolation were applied to make the uterine peristalsis inside the map easy to visualize. Quantitative analysis of the obtained strain and strain rate was able to distinguish between motion in the late follicular and late luteal phases.