Imaging methods

Peritoneum

Computed tomography is the method of choice in evaluating the peritoneal spaces and their associated peritoneal reflections. Careful opacification of the bowel with dilute gastrograffin will allow evaluation of peritoneal collections of fluid or masses, and intravenous contrast enhancement will allow identification of blood vessels in the peritoneal reflections. There is little need for positive contrast CT peritonography in evaluating suspected peritoneal disease. MRI provides good visualization of the peritoneal spaces and reflections; however, as the scans take longer to acquire than CT, bowel peristalsis and respiratory movement can degrade the images. Ultrasound is an inexpensive and effective method of seeking peritoneal collections, but as bowel gas reflects sound, this modality cannot survey the entire peritoneum. Conventional radiography, including barium examinations, only display peritoneal pathology indirectly and thus it has been superseded by CT.

Anterior abdominal wall

Computed tomography (CT) and magnetic resonance imaging (MRI) provide excellent anatomical detail of the anterior abdominal wall in the axial plane. MRI has superior soft-tissue contrast resolution than CT and can interrogate the patient in other planes, but the images are often degraded by movement associated with respiration. Ultrasound is useful in evaluating focal masses in the anterior abdominal wall, but does not demonstrate the anatomy as elegantly as CT or MRI. Conventional plain film radiography has no place in the evaluation of the anterior abdominal wall.

Anatomy of the peritoneum

The peritoneum is the largest and most complexly arranged serous membrane in the body, which in the male forms a closed sac, and in the female is penetrated by the lateral ends of the Fallopian tubes.