General indications for routine CT and MRI of the upper GIT
What are the general indications for routine computed tomography (CT) and magnetic resonance imaging (MRI) of the upper gastrointestinal (GI) tract?
General indications for routine abdominopelvic CT or MRI evaluation of the upper GI tract include:
- • Assessment of patients with clinical symptoms or signs potentially related to GI tract pathology for detection and characterization of the underlying etiologies.
- • Staging, pretreatment planning, response assessment, and restaging of patients with known GI tract malignancy.
- • Assessment of patients with suspected or known infectious, inflammatory, or ischemic bowel disease.
- • Assessment of patients with traumatic injury to the abdomen or pelvis for detection of bowel injury.
- • Evaluation of patients with known bowel obstruction to elucidate the underlying etiology.
Routine CT is typically performed using axial 5-mm sections during the venous phase of intravenous contrast enhancement following the administration of barium- or iodine-based positive oral contrast material. Positive oral contrast material increases the attenuation of the bowel lumen relative to the bowel wall while simultaneously distending the bowel lumen. Therefore, this type of oral contrast material is most often used to improve the detection of intraluminal bowel pathology and to detect and localize bowel leaks, particularly after prior bowel surgery.
Routine MRI is typically performed using multiplanar T1-weighted, T2-weighted, and diffusion-weighted image acquisitions, followed by dynamic contrast-enhanced T1-weighted imaging. However, oral contrast material is generally not administered.
