Inclusion Criteria:  Patient aged over 18 and under 50 Patient with symptomatic endometriosis with indication for surgery Showing at least one typical endometriosis lesion on MRI, greater than 5mm Accepting surgical management Having signed an informed consent after information Affiliate or beneficiary of a social security scheme  Exclusion Criteria:  Patient who has received an injection with GnRH (gonadotropin-releasing hormone ) analogues for less than 3 months (because it induces the quiescence of the disease which is no longer stimulated by estrogen secretion) Patient with a history of heavy abdominopelvic surgery Diabetic patient Patient unable to understand the interest of the study Patient already included in another therapeutic trial with an experimental molecule. Persons referred to in articles L1121-5 to L1121-8 of the PHC (public health code) (corresponding to all protected persons: pregnant woman, parturient, nursing mother, person deprived of liberty by judicial or administrative decision, minor, and person making the subject to a legal protection measure: guardianship or curators) Contraindications to PET Scanner (major claustrophobia, contraindication or hypersensitivity to 18-FDG or one of its excipients, contraindication or hypersensitivity to Ultravist® or one of its excipients, etc.) Contraindication to surgery or anesthesia