Ovarian follicle count by magnetic resonance imaging is greater in adolescents and young adults with polycystic ovary syndrome than in controls

OBJECTIVE: To use magnetic resonance imaging (MRI) to quantify the follicle number per ovary (FNPO) using biplanar measurements and determine the ovarian volume (OV) using three-dimensional measurements in adolescents and young adults with polycystic ovary syndrome (PCOS) and controls and compare the differences between these groups; to examine the relationships between FNPO and OV and metabolic markers associated with PCOS; to compare OV obtained by use of MRI and ultrasound between young patients with PCOS and controls. DESIGN: Cross-sectional study. SETTING: Outpatient within a major medical center in New York City. PATIENTS: Adolescent girls and young women aged 13–25 years with PCOS (n = 16) and body mass index–, age-, and ethnicity-comparable control subjects (n = 15). INTERVENTIONS: None. MAIN OUTCOME MEASURES: The OV and FNPO by use of MRI, OV by use of transabdominal pelvic ultrasound, anthropometric measurements, and biochemical and hormonal evaluation. RESULTS: The FNPO was higher in participants with PCOS (23.7 ± 4.6 follicles) than in controls (15.2 ± 4 follicles) when adjusted for menstrual age. The OV by use of ultrasound was higher in participants with PCOS (11.7 ± 5.6 mL) than in controls (8.1 ± 3.4 mL); however, OV by use of MRI did not differ between the groups. The OV by use of MRI and ultrasound correlated in participants with PCOS (r = 0.62) but not in controls. CONCLUSIONS: Our results are in line with prior studies showing that FNPO may be a more sensitive measure of polycystic ovary morphology than OV. The results of this study support the use of ovarian k, a promising diagnostic tool for PCOS, in young patients.