Diffuse-type gastric cancer: specific enhancement pattern on multiphasic contrast-enhanced computed tomography.

PURPOSE: To evaluate the enhancement pattern of diffuse-type gastric cancers (DGCs) on multiphasic contrast-enhanced computed tomography gastrography (CECTG).

METHODS AND MATERIALS: We studied 21 consecutive clinically diagnosed DGC patients who underwent CECTG. Gastric distension was obtained using effervescent granules. CT images were obtained 40 s (arterial phase) and 240 s (delayed phase) after injection of a nonionic contrast material. Two radiologists reviewed the CT images and analyzed layers and enhancement patterns. The readers evaluated the enhancement degree (mild, moderate, or marked) and calculated CT attenuation values by placing circular regions of interest (ROIs) within each layer of the lesion. The CT findings of 11 operated cases were correlated with pathological results.

RESULTS: Most lesions were double-layered in the arterial phase, with a moderately enhanced inner layer and a mildly enhanced outer layer, and single-layered in the delayed phase. The mean attenuation value of the inner layer (146 ± 32.8 HU) was significantly higher than that of the outer layer (80.4 ± 15.5 HU) in the arterial phase (p = 0.0001). In the pathological analysis, wall stratification was preserved in nine cases and not preserved in two cases.

CONCLUSION: Most DGCs showed a double-layered pattern in the arterial phase and a single-layered pattern with moderate enhancement in the delayed phase.