Quantitative assessment of peripheral and coronary artery lesions before and after balloon angioplasty: a comparison of intravascular ultrasound and angiography.

Intravascular ultrasound and conventional angiography were used to determine the degree of stenosis before and after angioplasty in 25 consecutive patients with peripheral arterial occlusive disease and 15 selected patients with coronary artery disease. Angiographic determinations of the luminal area and percent stenosis were made with the help of an automatic detection system, and the same parameters were evaluated planimetrically in the ultrasound studies. Following angioplasty of peripheral lesions, angiography demonstrated a significantly greater increase in mean luminal area (10.8 +/- 7.8 mm2 vs 5.8 +/- 4.0 mm2; P < 0.05) and a greater reduction in degree of stenosis (26% +/- 16% vs 14% +/- 11%; P < 0.05) than did the ultrasonic investigation. There was a significant but moderate correlation between values for the luminal area determined by angiography and ultrasound before angioplasty (r = 0.75; SEE = 4.8 mm2) and in normal proximal segments of coronary arteries (r = 0.79; SEE 4.1 mm2). Following angioplasty there was no significant correlation between angiographic findings and those determined by intravascular ultrasound in peripheral or coronary lesions. These results suggest that angiography and intravascular ultrasound are fundamentally different imaging and analysis techniques. Following angioplasty, conventional angiography rarely demonstrated dissection or intraluminal filling defects, while intravascular ultrasound detected plaque rupture and the presence of intraluminal atheroma in almost all cases. Quantitative determinations of luminal area and degree of stenosis rely on indirect measures with conventional angiography, while these parameters are determined directly by intravascular ultrasound.(ABSTRACT TRUNCATED AT 250 WORDS)