The ImageKids Study: Developing the pMEDIC and the PICMI

Inclusion Criteria: 1. Children (under 18 years of age) with established diagnosis of CD involving any location by the presence of accepted clinical, radiologic, endoscopic and histologic criteria (33, 34). 2. Enrolment at the time of performing ileocolonoscopy and esophageal-gastroduodenoscopy (EGD) as part of clinical care for any reason. 3. Children will be enrolled at any phase of the disease (at diagnosis and thereafter as required clinically). In order to ensure enough subjects with intestinal damage and since damage is progressing over time, enrolment will be stratified based on disease duration. Enrolment for each stratum of disease duration will be closed after reaching the expected sample size. * 20% of enrolled children will be within 3 months of diagnosis. * 20% of children will be between 3 months and 2 years. * 20% will be 2.01 to 3 years * 40% will have disease duration over 3-years. 4. Children may be enrolled in any disease activity state (PCDAI 0-100). Exclusion Criteria: 1. Young children requiring anesthesia for lack of cooperation will be excluded (since the enteric contrast cannot be administered during the 2 hours before anesthesia and it is crucial that the contrast be given just prior the test). 2. For the first 120 children only, subjects not expected to be available for 18 month follow-up, will be excluded (the last 120 subjects may be enrolled as they are not followed longitudinally).