How does MDCT assist in diagnosing small bowel obstruction?
MDCT is useful for evaluating small bowel obstruction; however, supine and erect abdominal radiographs should remain the initial diagnostic examination. MDCT with MPRs can determine the cause and level of obstruction, especially when high-grade. CT enteroclysis is the best imaging modality for low-grade obstruction. The site of obstruction or “transition zone” is the location in which the bowel proximal is dilated and bowel distal is decompressed. MDCT has a high specificity and negative predictive value, but low specificity for detecting ischemia. Bowel ischemia should be considered when wall thickening, mesenteric stranding, and mesenteric fluid are present. Pneumatosis, PV gas, and intramural hemorrhage are present in severe cases. MDCT can also diagnose closed-loop obstructions.