ISSN:0894-8771    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Color and power Doppler sonography are powerful ultrasound imaging techniques that acquire blood flow information in real time. This article reviews the physical principles used in the processing and display of flow information, with an emphasis on the operator-controlled variables affecting the information content of the image, and also presents an overview of clinical applications of these techniques.

ISSN:0894-8771    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Intraoperative ultrasound is being used routinely in surgery of the brain, spinal cord, liver, and pancreas. In neurosurgery of the brain and spinal cord, ultrasound is used to locate and characterize a lesion accurately and to show its relationship to surrounding normal anatomy, thereby reducing operative lime and tissue maceration and avoiding critical structures. In liver surgery, intraoperative ultrasound can locate or detect intrahepatic masses for resection, drainage, or biopsy; establish the relationship between a tumor and intrahepatic vascular structures; and facilitate the surgical resection of a mass by defining the exact site and boundaries of the lesion in relation to the intrahepatic vessels and ducts. Intraoperative ultrasound is the most sensitive technique for detecting tumors in the liver and provides important data that affect the surgical decision-making process. Intraoperative ultrasound is useful during pancreatic surgery for pancreatitis, carcinoma of the pancreas, and especially for localization of islet cell tumors; in the latter, it influences the surgery of insulinomas and gastrinomas. It can detect islet cell tumors that have not been localized by pre-operative imaging and are not visible or palpable at surgery.

ISSN:0894-8771    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The transjugular intrahepatic portosystemic shunt (TIPS) has become an important therapeutic tool in the treatment of portal hypertension and its complications. Because of its relatively low cost and noninvasive nature, sonography plays a key role in preprocedure assessment and postprocedure follow-up. Before the procedure, thorough gray-scale sonographic evaluation of the hepatic parnchyma and biliary tree, and Doppler evaluation of the relevant vasculature should be performed. A baseline sonogram should be obtained within a few days of TIPS placement to serve as a basis for comparison for subsequent surveillance studies. Signs of TIPS dysfunction include complete lack of flow in the shunt, a focal velocity gradient in the stent or in the draining hepatic vein, or a drop in flow velocity compared to the baseline examination.

ISSN:0894-8771    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Approximately 10 years ago, simultaneous advances in freezing and ultrasound technology allowed localized treatment methods for liver tumors to expand beyond surgical resection. Any technology causing localized tissue destruction requires practical delivery and accurate monitoring techniques to be broadly accepted and safe. In general, ultrasound is an operator-dependent technique. Safe and accurate cryotherapy thus requires superb intraoperative ultrasound evaluation, needle guidance, and monitoring of ice formation. Cryotherapy techniques have also evolved from a history of low-temperature treatments, thus becoming an important benchmark for other emerging ablative treatments. This article considers the role of cryotherapy for hepatic neoplasms in relation to the natural history of the diseases and treatment options. We then address state-of-the-art hepatic cryotherapy and the need for standardized delivery techniques for future comparisons.

ISSN:0894-8771    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0894-8771    

出版商:OVID    

年代:1998

数据来源: OVID