Purpose: We introduce a new volume-rendering method, named the "wall-carving (WC) technique," for luminal organs on contrast-enhanced multidetector row computed tomography (MDCT) using a gas-extension protocol. This study aimed to investigate the enhancement profile of the normal gastric wall, particularly focused on the relation between depth and gray value in the normal gastric wall, as a background to distinguish early gastric cancer (EGC) on MDCT.
Materials and methods: We retrospectively evaluated 32 data sets of abdominal CT with EGC. All data sets were obtained with a 64-detector-row CT after administration of an effervescent agent, anticholinergic drug, and intravenous contrast material. The enhancement profile was analyzed in the normal gastric body and antrum (n = 32) by the depth from the air-mucosa interface. We also examined the visual accessibility of the WC image. Institutional review board approval was obtained for this study.
Results: The profile curve showed that the thickness of the normal gastric wall was 3.75-6.25 mm (mean 4.8 mm), and the maximum enhancement was observed at the layer of 1.875 mm in each case. The enhancement pattern of the EGC was visually accessible, especially at a depth of 1.875-3.75 mm.
Conclusion: The enhancement profile showed a peak at the depth within the inner half-thickness of the estimated normal gastric wall. The WC image seems to be a good alternative for detecting tumor enhancement and its relation with the surrounding vascular structures in the gastric wall.