Prospective, monocentric, comparative, non randomised

Primary objective :

- to compare the diagnostic accuracy of sodium fluoride PET-CT and MRI using the conventional block and diffusion sequence in the search for bone metastases

Secondary objectives :

• compare accuracy of MRI diffusion and conventional MRI
• explore the evolution of the results of the different types of imaging over time or under treatment for patients with repeated examinations at 6 months

Prospective, monocentric, comparative, non randomised.

Organization of NaF PET-CT and MRI on the same day or within a 10 days period.

At 6 months :

• repeat both exams systematically if one of the initial tests showed a suspicious or doubtful abnormality
• final diagnosis by a committee of practitioners using the whole patient's file

Scheduled Project inclusion duration of 36 months (possible adaptation of duration in order to obtain the number of required patients)

Inclusion Criteria:

• Man or woman over 18 years
• Osteophilic cancer (breast, prostate, lung, kidney, thyroid) proved by pathological material, with a high probability of bone metastases
• With an indication to a bone examination: systematic search for metastasis for the staging or due to clinical or laboratory suspicion of bone metastasis
• Registered in a social security health scheme
• Written informed consent obtained

Exclusion Criteria:

• Classical contra-indications for PET CT (suspected pregnancy) or MRI (pacemaker, ferromagnetic material); for patients with a possibility of pregnancy (women of childbearing age without contraception and second part of the menstrual cycle, or the slightest suspicion), verification of the absence of pregnancy will be made by the beta HCG dosage before injection of radioactive tracer
• Uncontrollable claustrophobia with treatment anxiolytic
• Antitumor treatment started between the two imaging tests
• Imaging or treatment needed in emergency, if both tests are not performable in time required for the care
• Inaugural neurological complication
• Patient unable to undergo biomedical research (under guardianship or deprived of liberty)