Power and colour Doppler ultrasonography for the evaluation of the vasculature of the human corpus luteum

We used power Doppler imaging to examine neovascularizationin the corpus luteum (CL) in 12 healthy volunteers. We alsoinvestigated whether CL blood flow reflected luteal function.The ratio of the area of vessels in the CL to the area of asectional plane at the maximum diameter of the CL observed bypower Doppler (FA ratio) was used as a quantitative index ofthe vascularity of the CL. The pulsatility index (PI) was significantlylower in ovarian arteries with CL than without CL (P <0.05).Changes in ovarian arterial and intra-luteal PI appeared toreflect physiological changes in the vasculature of the CL.There was no correlation between the volume of the CL or theFA ratio and the concentration of progesterone. The patternof changes in the product of the FA ratio and the CL volumeand in the progesterone concentration was similar. The progesteroneconcentration was positively correlated with this product (r= 0.74, P < 0.01). The product of the FA ratio and the CLvolume plateaued during the mid- to late luteal phase, suggestingthe presence of functional and structural luteolysis. Thesefindings suggest that colour Doppler ultrasonography, includingpower Doppler imaging, can detect physiological changes in theblood flow of the ovary in the luteal phase, and may be a usefulnon-invasive tool for evaluating CL function.