Gastrointestinal Air Motion Artifact Which Can Be Mistaken for Active Gastrointestinal Bleeding in Multidetector Computed Tomography: Phantom and Clinical Study

OBJECTIVES: We investigated the computed tomographic characteristics of gastrointestinal air motion artifact (GIAMA), which can be misinterpreted as active gastrointestinal bleeding. METHODS: We simulated GIAMA using 3 types of air-ball phantoms (air-ball in water, air-ball in oil, air-water-ball in oil) and a bovine intestine in oil phantom. We also performed a retrospective clinical review of precontrast abdominal computed tomography images of 76 patients to investigate the frequency, location, shape, and maximum density of hyperdense GIAMA. RESULTS: In phantom studies, air motion artifacts appeared as dark and bright streak artifacts at the borders of a moving air-ball and water or oil. In the clinical study, hyperdense GIAMA was visualized in 60 (79.0%) of 76 patients. The small intestine was most commonly affected (46.4%), and the intramural type had the highest frequency (58.0%). CONCLUSION: Knowing the radiologic features of GIAMA can assists radiologists in identifying active gastrointestinal bleeding sites accurately.