Functional Study of the Hypothalamus in Magnetic Resonance Imaging (MRI) in Polycystic Ovary Syndrome (PCOS)

Inclusion Criteria: For all subjects * Aged from 19 to 30 years * Body mass index : 18-25 * Informed consent before inclusion * Do not smoke the 3 days before the MRI For Healthy volunteers subjects : * Regular cycles (between 25 and 35 days) AND ovulatory. * No signs of hyperandrogenism. * Subjects desirous of taking oral contraceptives (estrogen/progestin combination). * For the realization of the 2nd MRI: to be during the 3rd month of a treatment well followed by oestro-progestative monophasic minidose to 0,02mg of Ethinyl-oestradiol / 0,1mg Levonorgestrel. PCOS women: * PCOS defined by Rotterdam criteria * Needing a treatment with cyproterone acetate * To carry out the 2nd MRI: to be in progress during the 3rd month of a treatment well followed by 50 mg of Cyproterone acetate in association with 2mg / day of natural estradiol. Exclusion Criteria: * Hormone treatment within 3 months prior to inclusion (including birth control pill ) * On-going pregnancy (determined before each MRI scan visit) * Claustrophobia * Any metal or foreign implants (e.g., aneurysm clips, ear implants, heart pacemakers or defibrillators) * Diabetes or known dysthyroidism. * Current substance abuse (including smoking more than 5 cigarettes/day; determined using drug screening at the screening visit) * Pregnancy or breastfeeding the last 3 months. * Practice of intense physical exercise (ex jogging\> 10km) the day before the MRI. * Person incapable of consenting, or enjoying legal protection …