[Present possibilities of use of intravascular ultrasound examinations]

Catheter intravascular imaging is currently used as an adjunct to contrast angiography and angioscopy in peripheral and coronary arteries. At present the smallest catheters are 3.0 F (1.0 mm). Frequencies used are from 10 to 40 Mz, which allow high resolution imaging of structures close to the transducer. Mechanical and phased array systems are used, introduced either on the wire or through fine plastic catheter. More recent is the monorail system improving the flexibility and tracking of the mechanical systems. The review presents current status of catheters and diagnostic possibilities. Normal arteries have typical three layered appearance (intima, media, adventitia). Ultrasound can be reliably used to distinguish abnormal vascular segments. Atherosclerotic plaques can be subclassified on the basis of plaque composition. Thrombus is characterized by granular appearance with varying sonographic gray levels. Dissection and intimal flaps are also visualized by intravascular ultrasound. Potential utility of intravascular ultrasound in the assessment of endovascular interventions and its limitations are discussed.