1. Preovulatory Changes of Blood Flow in Different Regions of the Human Follicle 
Mats Brännström, Ulf Zackrisson, Hans-Göran Hagström, Birgitta Josefsson, Pär Hellberg, Seth Granberg, William P Collins, Tom Bourne 
Fertility and Sterility 
Volume 69, Issue 3, Pages (March 1998)
DOI: /S (97)00544-X

2. Fig. 1
Transvaginal ultrasound and color Doppler imaging of blood flow. The right hand images have the B mode turned off. (A) Day 10–12. A clear ring of vascularity is seen around the follicle. (B) Late ovulatory phase. Vascularity is most pronounced around the base of the follicle.
Fertility and Sterility  , DOI: ( /S (97)00544-X)

3. Fig. 2
Flow velocity waveforms in the follicle base (B), lateral sides (L), and apex (A) of a follicle on cycle day 11.
Fertility and Sterility  , DOI: ( /S (97)00544-X)

4. Fig. 3
Peak systolic velocity (PSV) in the follicle base (B), lateral sides (L), and apex (A) during days 10–12, early ovulatory phase (<20 hours after onset of LH surge), and late ovulatory phase (>20 hours after onset of LH surge). Value of apex in late ovulatory phase is 0. Significant differences between different areas at the same time points are indicated by ∗P<0.05 and †P<0.01. ‡P<0.01 indicates significant differences from the apex at days 10–12. The PSV value at the base of the early ovulatory phase is significantly higher (P<0.05) than the value at the base of days 10–12.
Fertility and Sterility  , DOI: ( /S (97)00544-X)

5. Fig. 4
Flow velocity waveforms in the follicle base (B), lateral sides (L), and apex (A) of a follicle during early ovulatory phase (<20 hours after onset of LH surge).
Fertility and Sterility  , DOI: ( /S (97)00544-X)

6. Fig. 5
Pulsatile index (PI) in the follicle base (B), lateral sides (L), and apex (A) during days 10–12 after menses, early ovulatory phase (<20 hours after onset of LH surge), and late ovulatory phase (>20 hours after onset of LH surge). Value of apex in late ovulatory phase is 0. †Significantly lower (P<0.01) than base and lateral sides of the same time points and apex at days 10–12.
Fertility and Sterility  , DOI: ( /S (97)00544-X)