Gastrointestinal tract

Magnetic resonance imaging (MRI) has achieved an increased role in the evaluation of gastrointestinal disorders. Techniques that have been used for MRI of the esophagus include high-resolution T2-weighted images, gadolinium enhancement, and cardiac gating. Although any part of the gastrointestinal tract, from the mouth to the anus, may become involved with Crohn’s disease, it most commonly involves the terminal ileum, frequently in association with disease in the right colon. Ulcerative colitis is a recurrent acute and chronic ulcero-inflammatory disorder of unknown etiology that affects the large bowel. In the setting of small bowel pathology, fistulas result from compromise in the integrity of the visceral wall and may be sequelae of infection, inflammation, neoplasia, radiation therapy, and ischemia (embolic, thrombotic, or vasoconstrictive). In the gastrointestinal tract, the small intestine is the region most sensitive to radiation injury.