Original Jpn J Radiol Technol 1999 ; 55 (12) :
Basic and Clinical Examination of Three-dimensional Analysis
for Gastric Cancer Using Helical CT Scanners

YUSHI HIRANO, HIRONOBU MATSUYA, MIZUO IRIYAMA, EMI SASAKI, MICHIAKI HIRAYAMA,1) and JUNKI FUKAURA1)
Department of Radiology, Otaru Ekisaikai Hospital
1)Department of Gastroenterology, Otaru Ekisaikai Hospital
Received Dec. 3, 1998; Revision accepted Sept. 30, 1999; Code No. 251

Summary
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.

Key words: Gastric cancer, Helical computed tomography(CT), Three-dimensional computed tomography(3D-CT), Measurement, Tumor size