Basic and clinical examination of three-dimensional analysis for gastric cancer using helical CT scanners

The purpose of this study was to evaluate the ability of three-dimensional helical CT (3D-CT) to depict gastric cancer. Depiction was evaluated in terms of elevations or depressions and tumor size. Elevation heights and depression depths were assessed using a gel-made phantom, while changing the scanning parameters of slice thickness, table-feed speed, and threshold of the CT value. For the measurement of tumor size, we first determined the appropriate critical parameters, since tumor size is greatly influenced by these parameters. A double-contrast medium, endoscopic images, and surgical stomach specimens were used to measure actual tumor sizes. The results showed that, since 3D-CT images can be taken from any angle, a clear picture of gastric cancer can be obtained without superimposition from the spine and colon gas. A good correlation was obtained between tumor size on 3D-CT images and measured size of tumors in the specimens, indicating that 3D-CT is useful for measuring the size of primary lesions of gastric cancer. The results suggest that 3D-CT could be a new modality for the examination of gastric cancer. (author)