1. Ovarian follicular volume and follicular surface area are better indicators of follicular growth and maturation, respectively, than is follicular diameter 
Yalcin Yavas, Ph.D., Minna R. Selub, M.D. 
Fertility and Sterility 
Volume 91, Issue 4, Pages (April 2009)
DOI: /j.fertnstert
Copyright © 2009 American Society for Reproductive Medicine Terms and Conditions

2. Figure 1
The curvilinear (parabolic) relationship of the follicular diameter to the calculated surface area and the calculated volume of follicles (top) and the fold increases in follicular surface area (S2/S1) and follicular volume (V2/V1) corresponding to the fold increase in follicular diameter (D2/D1 (bottom). When the follicular diameter increases from D1 to D2, the follicular surface area increases from S1 to S2 and the follicular volume increases from V1 to V2. The fold increases in follicular surface area (S2/S1) and in follicular volume (V2/V1) are the square and the cube, respectively, of the fold increase in follicular diameter (D2/D1).
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2009 American Society for Reproductive Medicine Terms and Conditions