Intravascular ultrasonic imaging is a promising technique for the study of arterial disease. Several investigators have shown that intravascular ultrasonography can differentiate normal from abnormal arteries in both the in vitro and in vivo setting.'-" The technique allows characterization of atherosclerotic plaque constituents and can be used for assessment of the effect of intravascular intervention. The ability to study in vitro the effects of balloon dilatation angioplasty on human atherosclerotic artery segments has been d ~c u m e n t e d . ~, ~ This paper describes in vivo results obtained in a patient using a real-time imaging system before and immediately after balloon dilatation angioplasty. The study was performed with a 5F catheter (1.6 mm) containing a motor-driven 32-MHz single-element transducer at its tip (Du-Med). The images were stored on a %inch videotape.
CASE REPORT
A 70-year-old man underwent percutaneous transluminal angioplasty of the right superficial femoral artery in 1985 for intermittent claudication. He returned 5 years later with recurrent symptoms of right-sided claudication. Angiography revealed a 50% stenosis of the right superficial femoral artery (Figure 1). Because the radiologist was unable to obtain transcutaneous access, the artery was dissectkd free under general anesthesia. Skin markers were placed for radiographic reference. Via direct puncture a 9F sheath was advanced distally into the artery. In-From the