Localization of the Patency Capsule by Abdominal Tomosynthesis

Abstract

Background/Aims: A patency capsule (PC) is used to assess intestinal patency in patients with known or suspected stricture, but PC localization by plain abdominal X-ray (AXR) is difficult in those patients in whom the PC is not detected in the feces. Tomosynthesis is a promising, cost-effective, and low-radiation digital tomographic technique. This prospective study evaluated its use for PC localization in the intestinal tract. Methods: The study subjects were 49 patients in whom the PC was not detected in the feces and was identified intra-abdominally on AXR films. PC localization in the small or large intestines by AXR alone or by tomosynthesis with AXR was compared with abdominal computed tomography (CT), which is the gold standard. Results: The PC was judged in the large and small intestines in 22 and 27 patients by AXR alone versus 34 and 15 patients, respectively, by tomosynthesis combined with AXR. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for PC detection by AXR alone were 52.9, 53.3, 56.2, 50.0, and 53.1%, respectively. The same parameters were 100, 100, 100, 100, and 100%, respectively, for tomosynthesis with AXR, which were identical to those of CT. Conclusions: Tomosynthesis with AXR is superior to AXR alone, though similar to CT, with respect to localization of the PC.