title: Virtual enteroscopy using air as the contrast material: a preliminary feasibility study.
abstract: BACKGROUND
  There are no studies to date using air as an enteral contrast medium for small bowel expansion in virtual enteroscopy. We examine the feasibility of air as an enteral contrast medium for virtual enteroscopy to achieve small bowel expansion.
  
  
  METHODS
  Two volunteers and six patients were examined. The six patients included three with small bowel tumors, one with small bowel hemorrhage and two with suspected cases of post-operative small bowel stenosis. A duodenal tube was inserted under fluoroscopy and approximately 2000 ml air was administered prior to scanning. A 16-detector row computed tomography apparatus was used with 2-mm thick slices. Intravenous contrast material was administered to the patients, but not to the volunteers. Computed tomography scanning was performed two to three times until the air reached the colon. Two examiners reconstructed multi-planar reformation, volume rendering and virtual endoscopy. These images were compared with double balloon enteroscopic findings and/or resected specimens.
  
  
  RESULTS
  There were no complications associated with this examination. In the volunteers the difference between the circular folds of the jejunum and those of the ileum was clearly visualized on virtual endoscopy. Angiodysplasia (9 mm), gastrointestinal stromal tumor (15 mm) and arteriovenous malformation were clearly detected by virtual endoscopy. In contrast, one tumor could not be detected because of inadequate intestinal distension. In the two suspected cases of the stenosis, the lesion was not identified because stenotic lesions were not differentiated from normal peristalsis of the small bowel.
  
  
  CONCLUSIONS
  Air is a feasible enteral contrast material for virtual enteroscopy.
authors.affiliation: Department of Surgery, Jichi Medical University, Tochigi-ken, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Endo
authors.forename: Kenichi
authors.initials: K
authors.lastname: Utano
authors.forename: Kazutomo
authors.initials: K
authors.lastname: Togashi
authors.forename: Tomonori
authors.initials: T
authors.lastname: Yano
authors.forename: Alan T
authors.initials: AT
authors.lastname: Lefor
authors.forename: Hironori
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Yasuda
authors.forename: Hideharu
authors.initials: H
authors.lastname: Sugimoto
mesh_terms: D000388:Air; D003287:Contrast Media / Q000008:administration & dosage*; D003937:Diagnosis, Differential; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007414:Intestinal Neoplasms / Q000175:diagnosis*; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014584:User-Computer Interface
chemical_list: D003287:Contrast Media