[The diagnosis of the depth of gastric cancer invasion by the ultrasonic method].

To establish the diagnosis of the depth of gastric cancer invasion by ultrasonic method scanned from the body surface preoperatively, 51 resected specimens of gastric cancer and 61 in-patients with gastric cancer were examined by Toshiba electro-linear-scanner (SAL-50A). Experiments of inserting a needle into the wall of resected stomach and removing some layers of specimens were done to determine the origin of the ultrasonic five layers structure. The tomographies, which were obtained from 51 specimens scanned in the water and 61 patients scanned from the body surface, were compared with their microscopic findings. The lesions which were limited in the anterior or posterior wall and located distal to the middle part of stomach body were able to be diagnosed accurately. It was difficult to diagnose the depth when there was a deep benign ulcer formation associated with an early cancer lesion or deformity of gastric wall due to compression of massive tumor. The depth diagnosed by ultrasonic method was sometimes deeper than final pathological one but rarely shallower than it. In this study, most advanced gastric cancer could be diagnosed correctly by this ultrasonic method preoperatively. This fact serves useful reference to determine the operative procedure.