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.