118 Figure 5.1: Example of acquired US frame from an in-vivo recording during the late follicular phase. Currently, most studies on the assessment and characterization of UP are based on qualitative measurements by visual inspection of transvaginal ultrasound (TVUS) recordings [7], [9]–[11], [12]. Visual characterization of the uterine activity in this manner is rather challenging and subjective, especially during the late luteal (LL) phase of the menstrual cycle, or right before embryo transfer (ET) during IVF treatment, when the uterus is expected to be more quiet compared to the other phases. A recent study shows that three medical professionals share only mild agreement on the direction and timing of UP by visual inspection of 80 TVUS recordings [13]. The lack of an objective and quantitative analysis of uterine contractility thus limits the ability to characterize UP and improve the success of IVF treatment. Following up on our recent work on dedicated ultrasound (US) speckle tracking for quantitative analysis of uterine motion [14], this article presents a quantitative assessment of the uterine activity focusing on the propagation of UP during a natural menstrual cycle as well as during an IVF cycle. In particular, velocity, direction, and coordination of UP are assessed. To quantify UP, uterine motion throughout the US recording must first be assessed. In the field of US-based speckle tracking, there are two major approaches to estimate motion, namely, block matching (BM) and optical flow
RkJQdWJsaXNoZXIy MTk4NDMw