How to discriminate between normal and polycystic ovaries: transvaginal US study.

Transvaginal sonography was used in 29 women with regular menstrual cycles and 52 patients with the polycystic ovary syndrome to determine cutoff levels in the size and number of ovarian follicles and ovarian echogenicity and volume for diagnosis of polycystic ovaries. Median values of the mean size and number of follicles and ovarian volume were, respectively, 5.1 mm, 5.0, and 5.9 mL in control subjects and 3.8 mm, 9.8, and 9.8 mL in patients. Ovarian stroma echogenicity was normal in 26 control subjects (90%) and moderately increased in three control subjects (10%), whereas it was markedly increased in 28 patients (54%), moderately increased in 21 patients (40%), and normal in 13 patients (6%). The sensitivity and specificity of moderately or markedly increased echogenicity of ovarian stroma in the diagnosis of polycystic ovaries was 94% and 90%, respectively. The greatest power of discrimination between normal and polycystic ovaries was obtained with combined measurement of follicular size and ovarian volume (sensitivity, 92% [48 of 52 patients]; specificity, 97% [28 of 29 control subjects]).