Evaluation of early gastric cancer at multidetector CT with multiplanar reformation and virtual endoscopy

Early gastric cancer (EGC) is defined as a carcinoma in which invasion is limited to the mucosa and submucosa, regardless of lymph node status and distant metastasis. Recent advances in multidetector computed tomography (CT) with multiplanar reformation (MPR) provide a powerful tool for identifying gastric wall invasion and the perigastric extent of gastric cancer. In addition, MPR images confer advantages in the assessment of both intra- and extraluminal processes of the gastric wall and the evaluation of more distant regions, such as the paraaortic lymph nodes and other abdominal organs. Virtual endoscopy performed after air distention of the stomach can aid in the evaluation of gastric endoluminal morphologic features and the extent of EGC. Moreover, virtual endoscopy helps in detecting subtle mucosal changes and differentiating them from submucosal lesions in the same way as conventional endoscopy. Virtual endoscopy can depict abnormal endoluminal lesions within a wider field of view than can conventional endoscopy, and there are no "blind spots" because retrospective image reformation is available, which provides useful information for preoperative mapping. Multidetector CT with MPR and virtual endoscopy is a powerful, noninvasive tool for the early detection and accurate preoperative staging of EGC.