Accuracy of 64 Sliced Multi-detector Computed Tomography in Diagnosis of Small Bowel Obstruction
Sopa Pongpornsup MD*, Kullaya Tarachat MD*, Sittipong Srisajjakul MD*
Affiliation : * Department of Radiology, Siriraj Hospital, Mahidol University, Bangkok, Thailand
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.
Keywords : Small bowel obstruction, Multi-detector computed tomography, Small bowel sign
