Ultrasound Evaluation of Crohn's Disease

Subjects will receive ultrasound (US) imaging of the terminal ileum without and with sulfur hexafluoride contrast at baseline, 4 week and 6 months. Subjects will receive one to two milliliters of the contrast agent.

Subjects will receive US Imaging with the GE Logiq E9 Ultrasound Scanner at baseline, 4 week and 6 months without and with contrast.

Subjects will receive US Imaging with the Verasonics Ultrasound Scanner at baseline, 4 week and 6 months without and with contrast.

Subjects will receive MRE imaging at baseline and 6 months as part of regular clinical care.