Principles of angioplasty guidance using ultrasound.

Marker bands that cast dense shadow on X-ray are placed at crucial points on a catheter (for example on a peripheral angioplasty catheter on either side of the balloon) so that those parts of the catheter can be guided inside the body by X-ray. For catheter guidance by ultrasound, an ultrasound sensor in the mid-balloon region of an angioplasty catheter is integrated to the scanhead of an ultrasound scanner, via a catheter system interface (CSI). When the sensor in the catheter is imaged by the ultrasound scanner, the CSI injects a bright arrow corresponding to its position. This allows accurate catheter guidance using ultrasound. This paper describes the principles of ultrasound guidance of catheters and the initial clinical experience using this new catheter system (Echomark) in carrying out peripheral transluminal angioplasty.