Detection of the Transition Zone and Adhesions in the Diagnosis of Adhesive Small-bowel Obstruction: the Added Value of Ultrasonography (US) in Comparison with Only CT Imaging

ABSTRACT

PURPOSE: We aimed to assess retrospectively the benefit of the use of ultrasonography (US) in comparison with the use of only CT imaging for the detection of the transition zone and adhesions to determine a diagnosis of adhesive small-bowel obstruction (SBO). MATERIALS AND METHODS: Thirty-five patients underwent an additional US examination after CT imaging to determine a diagnosis of SBO. All of the patients were surgically confirmed as having adhesive SBO. The CT images were interpreted for the location of the transition zone, the location and shape of adhesions and for other SBO findings. All of the additional US scans were performed with reference to the CT findings. The standard of reference for the diagnosis was the surgical findings. The diagnostic accuracy and mean confidence score of the transition zone location and the detection rate of adhesions were evaluated for both CT imaging alone and for CT imaging with additional US. RESULTS: The diagnostic accuracy to locate the transition zone was significantly increased with the use of additional US with CT imaging (94.6%, 33/35) as compared to 65.7% (23/35) with the use of only CT imaging (p = 0.01). The mean confidence score was significantly increased (by 0.95) with the use of an additional US examination (p < 0.01). The detection rate for adhesions was 20% (7/35) with the use of only CT imaging and the detection rate was 68.6% (24/35) with the use of an additional US examination. CONCLUSION: The use of a US examination in addition to CT imaging can increase the accuracy and confidence to locate the transition zone and can increase the rate to detect adhesions in patients with adhesive SBO. An additional US examination may be especially helpful when the CT findings are equivocal.