Helical CT in the diagnosis of small bowel obstruction

With recent technologic developments, the role of computed tomography (CT) in the diagnosis of bowel obstruction has expanded. CT is recommended when clinical and initial radiographic findings remain indeterminate or strangul ation is suspected. This modality clearly demonstrates pathologic processes involving the bowel wall as well as the mesentery, mesenteric vessels, and peritoneal cavity. CT should be performed with intravenous injection of co ntrast material, and use of thin sections is recommended to evaluate a part icular region of interest. CT is reported to have a sensitivity of 78%-100% for the detection of complete or high-grade small bowel obstruction but ma y not allow accurate diagnosis in cases involving incomplete obstruction. I n such cases, the use of adjunct enteroclysis is indicated. Furthermore, mu ltiplanar reformatted imaging may help identify the site, level, and cause of obstruction when axial CT findings are indeterminate. CT can also demons trate findings that indicate the presence of closed-loop obstruction or str angulation, both of which necessitate emergency exploratory laparotomy. Unf ortunately, these pathologic conditions may be missed, and patients with su spected severe obstruction or bowel ischemia in whom CT and clinical findin gs are widely disparate must also undergo laparotomy. In general, however, CT allows appropriate and timely management of these emergency cases.