INTRAMURAL INVASION OF GASTRIC-CANCER - EVALUATION BY CT WITH WATER-FILLING METHOD

Objective: Our goal was to clarify the ability of CT to evaluate intramural invasion of gastric cancer. Materials and Methods: We reviewed bolus-enhanced CT images performed with orally administered 40-600 ml of water in 59 early gastric cancers and 22 advanced gastric cancers mimicking early gastric cancers macroscopically. Results: CT was able to reveal 49% of early gastric cancers and 68% of advanced gastric cancers mimicking early cancers. Twenty-seven gastric tumors were detected in two or three layered structure of wall. Morphologic features of early gastric cancers are strong enhancement without wall thickening and thickened inner layer with normal middle and outer layers. Morphologic features of early advanced gastric cancers are a thickened wall with disappeared middle and outer layers and transmural enhancement with wall thickening. If one of these features was used to predict whether the tumor was early or early advanced gastric cancer in detected cases, specificity was 93-100%, sensitivity was 7-72%, and positive predictive value was 80-100%. Conclusion: We evaluated whether the wall pattern of gastric tumors on CT can provide useful information about intramural invasion.