Three-dimensional power Doppler angiography of cyclic ovarian blood flow

The purpose of this study was to assess the vascular indices generated by 3-dimensional (3D) power Doppler angiography by evaluating the cyclic changes in the vascularity of normal ovaries, including those that were ovulating, nonovulating, and hormonally suppressed.

In this prospective longitudinal observational study, a cohort of premenopausal regularly menstruating women with no known ovarian disease underwent 3D power Doppler imaging every 2 to 3 days for the duration of 1 menstrual cycle. Four indices were generated: vascularization index (VI), flow index (FI), vascularization-flow index (VFI), and mean grayness. Comparisons of vascularity were made between ovulating, nonovulating, and hormonally suppressed ovaries. Normal ranges were established and graphed longitudinally.

Eighteen participants (36 ovaries) ages 28 to 45 years underwent an average of 10 examinations, yielding 368 acquired ovarian volumes for analysis. Seven participants used hormonal contraception. The VI, FI, and VFI were closely correlated (Pearson product moment correlation coefficients, 0.52-0.95). The vascular indices of ovulating ovaries were significantly higher than those of nonovulating ovaries (VI, FI, and VFI, all P < .001), with the largest discrepancies during the luteal phase. Hormonally suppressed ovaries had significantly lower vascularity throughout the cycle (VI, P < .002; FI, P < .001; VFI, P < .007). The vascular indices of all groups appeared to drop during the late follicular period and then rise again.

The VI would suffice as the principal vascular parameter for 3D power Doppler analysis. Preovulatory scans may be more useful for distinguishing pathologic vascularization. Hormonally suppressed ovaries have significantly lower vascularity throughout the cycle. Normal-appearing ovaries with vascular indices above the normal ranges established by these data may warrant further investigation.