Abstract
Although ultrasonic examination has recently made much progress, it is not always available for diagnosis of diseases in the abdomen when severe obesity, intestinal gas or ribs iffterferes the ultrasound quality. In order to overcome these problems, an approach from the inside of the abdomen has been required. On laparoscopic examination, a combination with ultrasonography will be also useful to obtain the inner information of the lesions observed on the surface. We have developed a system equipped with an ultrasonic laparoscope in collaboration with olympus Optical Co. and Aloka Co.. Resolution of 7.5 MHz scanner of this system was examined using a test apparatus. Two point discrimination was laterally 1.0 to 1.3mm up to 2.5cm deep in water and was much more sharp as compared with Model RT-2000 (ultrasonic equippment made in Yokokawa Co., 3.5 MHz) with which it has 3.0 cm at 1.0cm deep in water, though the axial discrimination was not different from each other. When compared with ultrasonic examination from the outside of the abdomen using experimental models of gallbldder stones, biliary obstcuction, liver cyst and granuloma in dogs, this system was proved to provide much more fine and shapa images. In a patient with liver cirrhosis in whom an irregularly nodular lesion on the liver surface suggesting hepatoma was observed by laparoscopy, examination with this systm was performed on the lesion. There found strong echoes around portal vein suggesting liver cirrhosis, and tumor echo was not detected. Surgical biopsy disclosed liver cirrhosis without tumor. During the experiments with this system, we found out several problems in operability, and based on the experience obtained here we have developed an improved model of this system.
