Intraoperative ultrasonography

Abstract

Fig. 1. Number and type of intraoperative ultrasonographic examinations performed at the Mayo Clinic from 1989 to 1993.Intraoperative ultrasonography is a rapidly growing imaging technique that can be used in a variety of applications throughout the body. It is particularly useful in the abdomen, where, at the time of operation, it is used to confirm findings shown by preoperative imaging studies, discover vital new information that may influence the course of surgery, and to confirm the completeness of an operation. Intraoperative ultrasonography is often the final imaging procedure performed in the patient undergoing an abdominal operation, and therefore it is the last opportunity for direct communication between radiologist and surgeon before an operation is completed. It is likely that the unique imaging information that is provided by intraoperative ultrasonography will result in improved surgical results and patient survival and may result in decreased health care costs by decreasing the need for reoperations.The use of intraoperative ultrasonography has increased rapidly during the last 10 years. The first intraoperative ultrasound examination was performed in the early 1960s when A-mode ultrasound was used to localize biliary calculi intraoperatively [1,2]. However, a number of technological advances were necessary before this technique could to be of practical use. The development of portable ultrasound equipment, miniaturized real-time probes, and high-frequency transducers with excellent spatial and contrast resolution have all combined to allow intraoperative ultrasonography to realize its full potential. Today, in our practice, although intraoperative ultrasonography accounts for fewer than 1% of all ultrasound examinations performed, its rate of growth has been rapid and the number of intraoperative exams has increased by over 200% during the last 5 years (Fig. 1). The most important uses of intraoperative ultrasonography include neurological applications in the brain and spine, abdominal uses in the liver and pancreas, and vascular applications in the renal and carotid arteries. Neurological applications, although still of importance, have decreased considerably since the advent of MR and CT-guided stereotactic neurosurgery. This review will concentrate primarily on applications in abdominal parenchymal organs such as the liver and pancreas, and abdominal vascular applications in the renal arteries following endarterectomy, which are the most rapidly growing applications of abdominal intraoperative ultrasonography in many radiology practices.In the past, many radiologists have been reluctant to become involved in intraoperative ultrasonography because of a concern about the demands of this procedure on the resources of an ultrasound department in terms of total time commitment, ultrasound machine use, and the unpredictability of the time of the call to the operating room [3,4]. However, the time that the radiologist spends away from the department can be minimized by careful coordination of the tim...