Value of PET/MR Enterography in the Assessment of Crohn's Disease Using a Collagen-binding Radiotracer.

Inclusion Criteria: * Age greater than 18 years * Biopsy confirmed/suspected Crohn's disease * Ability to give written informed consent Exclusion Criteria: * Electrical implants such as cardiac pacemaker or perfusion pump; * Ferromagnetic implants such as aneurysm clips, surgical clips, prostheses, artificial hearts, valves with steel parts, metal fragments, shrapnel, metallic tattoos anywhere on the body, tattoos near the eye, or steel implants ferromagnetic objects such as jewelry or metal clips in clothing; * eGFR of less than 30 mL/min/1.73 m2 within the past 90 days; * Pregnant or breastfeeding (a negative quantitative serum hCG pregnancy test will be required for females of child-bearing age before the subject can participate); * History of claustrophobia or any other condition considered likely to preclude the patient from lying comfortably in the MR/PET scanner for the duration of the exam; * Research-related radiation exposure exceeds current Radiation Safety Committee guidelines (i.e. 50 mSv in the prior 12 months); * BMI \> 33 (limit of the PET/MR table); * Co-morbid conditions known to cause fibrosis that may interfere with the results of the exam (e.g., retroperitoneal fibrosis, mesenteric panniculitis, desmoid tumor etc.) * Determined by the investigator(s) to be clinically unsuitable for the study (e.g. based on screening visit and/or during study procedures);