Inclusion Criteria:  Patient referred to the South-Western France referral center for complex bone and joint infections (Crioac GSO, infectious diseases and orthopedic surgery units) for suspicion of first episode of prosthetic hip or knee infection. Suspicion of prosthetic joint infection evolving for more than one month. Patient for who routine diagnosis includes both bone scintigraphy and leukocytes scintigraphy. Patient with positive bone scintigraphy. Being affiliated to a health insurance system Having signed an informed consent form (later than the day of inclusion and before any examination required by the research)  Exclusion Criteria:  Patient with active cancer. Patient with negative bone scintigraphy. Patient who cannot stop antibiotics 14 days before exams. Pregnant or breastfeeding women. Women of childbearing age but not using effective means of contraception. Patient concerned by articles L 1121-5 to L 1121-8 (persons deprived of their liberty by a judicial or administrative decision, minors, persons of legal age who are the object of a legal protection measure or unable to express their consent). Subject in relative exclusion period from another study protocol. Known contraindications to PET exam with radiopharmaceutical injection (hypersensitivity to radiopharmaceutical and/or to excipients).