4-D Assessment of Endometrial Vascularity Using Spatiotemporal Image Correlation: A Study Comparing Spherical Sampling and Whole-Tissue Analysis

Our aim in the study described here was to assess the feasibility of spatiotemporal image correlation power Doppler quantification of the endometrium with two techniques: spherical samples and whole tissue. We scanned 51 women in the midluteal phase of the menstrual cycle: STIC assessment of the whole endometrium was not possible in 10% of cases, whereas spherical analysis was possible in all. The time taken for data set analysis was much longer for the whole endometrium compared with spherical analysis (1478.9 ± 291 s vs. 266.8 ± 39.3 s, p < 0.05). Intra-class correlation coefficients for the vascularization flow index (VFI) were similar for both methods. Volumetric vascularity indices were higher when spherical sampling was conducted. Significant cycle-to-cycle variability in the vascularity indices was present, with coefficients of variation exceeding 20% for both techniques. We found that STIC power Doppler quantification of the whole endometrium is possible in the majority of cases, however, it is time consuming and limited by significant cycle-to-cycle variability.