Ovarian parenchyma color-Doppler ultrasonographic images showing blood flow changes during the different phases of the cycle: end of the proestrus (a), three days before ovulation (b), one day before ovulation (c), ovulation (d), one day after ovulation (e), four days after ovulation (f).
 

Evolution of the colored Doppler area (pixel) during the pre and post ovulatory phase in the left and right ovaries.  

Correlation between the number of the preovulatory follicle and the colored Doppler area (pixel) on the day of ovulation 

Correlation between the diameter of the preovulatory follicle and the colored Doppler area (pixel) on the day of ovulation