Four-Section Multidetector Computed Tomographic Imaging of Bowel Obstruction

Abstract

To compare the diagnostic performance of axial and coronal views in multidetector-row computed tomography (MDCT) of patients with small-bowel obstruction (SBO) or large-bowel obstruction (LBO). Among 157 patients with clinical and radiographic findings of BO, 73 patients, who underwent MDCT and were found to have surgically proven SBO (49/73) or LBO (24/73), were retrospectively evaluated. Portal-enhanced MDCT was performed using 4 x 2.5-mm collimation; 3-mm-thick axial images were reconstructed with 2 mm of increment. Coronal views were reformatted using 3-mm-thick sections with 1 mm of increment. Three radiologists analyzed axial (session A), coronal (session B), and axial plus coronal images (session C) to identify the site, cause, and type of BO. To correlate surgical findings and MDCT results, the bowel was divided into duodenum, oral jejunum, aboral jejunum, oral ileum, aboral ileum, cecum/ascending colon, transverse colon, descending colon, and sigmoid colon/rectum. The mean diagnostic accuracy and the mean confidence score of each reader and each reading session were calculated. The diagnostic accuracy of axial images was higher than that of coronal views (P = 0.014) in SBO, whereas no significant differences were found in LBO. The definition of the SBO cause was correctly assessed in 45 of 49 patients during session A, in 40 of 49 during session B, and in 45 of 49 during session C. In patients with LBO, the cause was correctly assessed in 21 of 24 patients during session A and in 22 of 24 patients during sessions B and C. All readers interpreted axial plus coronal images with a significantly higher confidence level than axial or coronal views alone, either for the detection of the site (P = 0.002) or for the identification of the cause (P < 0.001) of SBO and LBO. The MDCT allowed accurate detection of the site and the cause of obstruction. In SBO, axial images yielded a higher diagnostic accuracy than coronal views, whereas in LBO, no differences were found between axial and coronal planes. The reading of axial plus coronal views significantly improved diagnostic confidence.