[Diagnosis of the depth of gastric cancer invasion by endoscopic ultrasonography].

Endoscopic ultrasonography (EUS) is useful to diagnose the depth of invasion because of obtaining tomographic image of gastric cancer. Stomach layer has a 5-layer structure. Gastric cancer is visualized as low echoic tumor image by EUS. Massive invasion of gastric cancer is viewed as low echoic and clear boundary image. Diffuse invasion is imaged unclear boundary echo and visualized thick layer with remaining layer structure. Invasion depth of gastric cancer by EUS is diagnosed according to level of wall destruction. When depressed type cancer has ulceration in cancer nest, echoic image is modified with fibrous tissue. The diagnostic criteria of depressed type cancer classified into EUS imaging of cancer in consideration for image modified by fibrous tissue accompanied ulceration.