[Invasive ultrasound: value of intraoperative and laparoscopic ultrasound imaging]

Compared to preoperative ultrasound and computed tomography as well as intraoperative inspection and palpation intraoperative ultrasonography has the highest sensitivity for the detection of liver metastases of colorectal carcinomas. With this method preoperative occult liver metastases can be found in 15% of the patients; in 5% these are solitary metastases which cold easily be resected. During resection of liver tumors intraoperative ultrasonography serves for the exclusion of multifocal tumor development or satellite metastases; furthermore it is important for planning the plane of resection and the appropriate safety margin. Without intraoperative ultrasonography modern liver surgery cannot be performed. Laparoscopic ultrasonography is indicated for laparoscopic staging of gastrointestinal tumors and also serves for the detection of occult liver metastases. During this procedure focal liver lesions can be biopsied under combined laparoscopic and sonographic view.