外科領域における超音波診断に関する研究 第2編 超音波による肝腫瘍診断に関する研究

The high request of the preoperative diagnosis for liver metastasis of cancer is the claimed factor in the surgical field. Many kinds of examinations; i. e, physical examination, liver function test of serum, liver biopsy, laparoscopy, roentogenological diagnosis and others were using for this purpose, but the diagnosis was unliable yet. Recently, the clinical application of radioisotope is remarkably advanced, and the scintiscanning is used as a standard tool for clinician. The advances of the ultrasonic diagnostic apparatus and techniques is also evident. In this paper the investigations were carried out by combinating method of ultrasonic diagnosis with hepatoscintigram. The excellent point of this method is to improve the weak points each other of the hepatoscintigram and ultrasonic diagnosis. By means of hepatoscintigram every large space occupying lesion (more than 2-3cm in diameter) in liver can be seen but the depth and structure of the lesion can not be recognized, however the ultrasonic A-scope method is able to clarify the laters. Ultrasonic method is able to diagnose the character of the aimed occupying lesion, respectively. Generally, the continuous multiplying echo indicate the cancer tissue, the boundary wall echo is the cyst or abscess, and the gall stone is easily diagnosed at the same time. But the risk for over diagnosis is respective in two methods, the diagnosis by this combinating method must be carefull in considerations. Combinating method of ultrasonic A-scope with hepatoscintigram gave a good result for liver disease. But the nature of the echoes obtained various kind of livers tend to over-lap. Therefore it is difficult to remark the distinguished accuracy in all cases. The suitable frequency was 2.25MC and a barium titanate of 10mm in diameter was used. Now we are using the ultrasonic contact compound scope, Aloka SSD-10. In this paper some results and problems of this method were presented. The examination is carried out at the lower right chest wall or through the abdominal wall. Several normal human livers were examined first. Some echograms of them were shown. Details of the deep structure are shown when STC (Sensitivity Time Control) is on. But concerning intrahepatic structure, it demonstrates more clearly than when STC off. Some echo patterns of the metastatic liver cancers were shown. A patient who had alarge tumor at his upper right abdomen was examined. His echogram of liver is shown. There is a large tumor (4cm in diameter) at the deep region in liver and the back surface of liver is pressured backwards. But no malignant echo pattern is seen. In some cases of our examinations malignant tissues showed only the surface and bottom echoes. The result of operation actually showed the metastatic cancer of liver, corresponding with the echogram. This fact suggests there are various degrees of absorption of ultrasound among cancers.