Endovascular ultrasound imaging is a new technique that can be used to monitor intraoperatively the effects of balloon angioplasty or to inspect the quality of vascular reconstruction, such as endarterectomy or bypass surgery. The technique is based on high frequency ultrasonic imaging (30-40 MHz) using a rotating single element transducer mounted in an 8F catheter tip, providing 360 degrees cross-sectional real time images. The clinical application is based on the high correlation between the ultrasonic images and the histological characteristics of the corresponding vessel wall tissue and lumen geometry, as has been established in previous in vitro studies. Endovascular ultrasound assessment of percutaneous angioplasty procedures or intraoperative vascular reconstruction has become an adjunct to angiographic and/or angioscopic monitoring.