and polycystic ovaries W.M.Buckett1,4, R.Bouzayen2, K.L.Watkin3, T.Tulandi1 and S.L.Tan1

4To whom correspondence should be addressed Since the widespread use of transvaginal ultrasound to diagnose polycystic ovary syndrome (PCOS), a cardinal feature has been shown to be the presence of a bright, highly echogenic stroma. This is usually assessed subjec-tively. The objective of this study was to determine whether ovarian stromal echogenicity when measured objectively actually differed between women with polycystic ovaries and those with normal ovaries. A total of 67 women underwent a detailed ultrasound assessment before con-sidering assisted conception treatment. Ovarian morpho-logy was assessed and total ovarian volume, stromal volume, peak stromal blood flow velocity and mean stromal echo-genicity were measured. The stromal index (ratio of mean stromal echogenicity to mean echogenicity of the entire ovary) and total stromal echogenicity were also calculated. Ovarian volume, stromal volume, and stromal peak blood flow velocity were all significantly higher in ovaries from women with PCOS. There was no difference in the mean stromal echogenicity, although the stromal index was signi-ficantly greater in women with polycystic ovaries. The apparent subjective increase in stromal echogenicity in women with polycystic ovaries, as exemplified by the greater stromal index, is due to a combination of the increased volume of ovarian stroma and the significantly lower mean echogenicity of the entire ovary in these women. Key words: echogenicity/ovary/polycystic ovary syndrome/ stroma/ultrasoun