CT evaluation of gastric lesions with three-dimensional display and interactive virtual endoscopy: comparison with conventional barium study and endoscopy.

OBJECTIVE This study was undertaken to assess the feasibility of three-dimensional (3D) CT rendering using shaded-surface display (SSD) and ray sum display and virtual endoscopic images of the stomach for simultaneous evaluation of intraluminal and extraluminal abnormalities compared with conventional upper gastrointestinal barium studies and endoscopy. SUBJECTS AND METHODS Our prospective study consisted of 39 patients with gastric lesions (17 gastric carcinomas, nine gastric polyps, five gastric varices, five gastric submucosal tumors, one lymphoma, one case of Menetrier's disease, and one gastric erosion) detected by endoscopy and barium study. All 3D CT images were reconstructed using SSD, ray sum display, and virtual endoscopic techniques. Three-dimensional images were evaluated for ability to reveal the range and morphologic features of the gastric lesions. RESULTS All SSD, ray sum display, and virtual endoscopic images successfully revealed five of the eight early-stage gastric carcinomas and all nine advanced-stage gastric carcinomas. Submucosal tumors were revealed on 3D CT approximately as well as on conventional endoscopy. Interactive evaluation of virtual endoscopic images and multiplanar reconstructions provided useful information regarding intraluminal and submucosal gastric involvement by gastric varices, submucosal tumor, advanced gastric carcinomas, and lymphoma. This kind of information could not be obtained by conventional endoscopy or double-contrast study. CONCLUSION Three-dimensional CT used in conjunction with virtual CT endoscopy proved helpful in identifying gastric lesions. Also, virtual CT endoscopic images with the interactive display of multiplanar reconstructions proved useful in identifying both intraluminal and submucosal components.