The purpose of this study will permit to determine the role of FDG PET/CT to diagnose Crohn Disease and recurrence of Crohn disease after having compared results of PET/CT's with results of exams routinely performed(colonoscopy and bowel follow through).

Crohn disease is an inflammatory disease of the digestive system that may affect the small and large intestines. Remission and recurrence clinically characterized its development. When recurrence occurs, a careful examination is necessary in order to determine the extent and the severity of the disease. Actual exams performed are invasive and uncomfortable(colonoscopy and bowel follow through). Compare to these exams, PET/CT is less fierce to undergo and has less risks. Two groups are proposed in this project: 15 patients will be enroll in the active disease group and 15 patients will be enroll in the remission group. In regards of the area and the extent of the disease,PET/CT exams shall provide similar information than what usual tests provide. PET/CT exams shall also provide more information in order to better differentiate inflammatory stenosis from scars stenosis especially located in the small intestine.

Inclusion Criteria:

• Men or women known having a Crohn's disease de novo diagnosis or a Crohn's disease recurrence based on a seven days questionnaire and a physical exam.
• Men or women with a past history of Crohn's disease but considered clinically in remission based on a seven days questionnaire, a physical exam and a Crohn's disease activity index (CDAI) score < to 150.

Exclusion Criteria:

• Men or women less than 18 years of age
• Pregnancy
• Breastfeeding
• Renal failure
• Suspicion of a Crohn's disease infectious complication (abscess,fistula)
• Infectious colitis determined at the initial checkup
• Diabetes
• Severe allergy to iode contrast