Accuracy of 64 sliced multi-detector computed tomography in diagnosis of small bowel obstruction

Abstract

Objective: The purpose of the present study was to determine the accuracy of 64 sliced multi-detector computed tomography (MDCT) in the diagnosis of patients with suspected small bowel obstruction (SBO) and identify the definite cause of SBO for further investigation or treatment.

Material and method: A retrospective study was performed on 35 patients with suspected SBO who underwent 64 sliced MDCT to establish the diagnosis and cause of SBO. The patients were enrolled from January 1, 2005 to June 30, 2007. The MDCT scan of whole abdomen from patients with suspected SBO were retrospectively evaluated by two gastrointestinal radiologists without knowledge of the patients history determined the presence or absence of SBO, cause, location, small-bowel feces sign, complication (sign of associated bowel strangulation), and confident on a five-point scale. Sensitivity and specificity estimates with confidence intervals were calculated. Weighted-kappa statistics were used to estimate agreement between readers.

Results: Twenty-five patients ultimately proved to have SBO, and ten patients had no evidence of SBO. The overall sensitivity, specificity, and accuracy of 64 sliced MDCT to establish the diagnosis of SBO were 96%, 100%, and 97%, respectively. The final diagnosis was established either by surgery (13 patients) or by the clinical evolution (12 patients). Causes of SBO included adhesions (n=10), metastases (n=4), post-radiative enteropathy (n=1), internal hernia (n=3), ileitis (n=2), inguinal hernia (n=1), submucosal hemorrhage (n=1), benign stricture secondary to chronic pancreatitis (n=1), midgut volvulus (n=1), and SMA syndrome (n=1). When obstructions were classified into low and high grade obstruction, CT results could be used to identify correctly 100% (13 of 13) of high grade SBO and 58% (7 of 12) of low grade SBO. The 64 sliced MDCT yielded one false-negative for patients with partial SBO due to adhesion band Small-bowel feces sign was detected in 4 of 25 patients, who were diagnosed as SBO.

Conclusion: The 64 sliced MDCT is a highly sensitivity and specificity method to diagnose SBO and cause of obstruction. The ability of MDCT to show the cause of SBO makes CT an important additional diagnostic tool when specific management issues must be addressed.