INTRAVASCULAR ULTRASONOGRAPHY BEFORE AND AFTER INTERVENTION - IN-VIVOCOMPARISON WITH ANGIOGRAPHY

Purpose: To compare the additional capacity of intravascular ultrasono graphy versus angiography to assess morphologic features and lumen dim ension, 37 patients undergoing vascular intervention of the common ili ac or superficial femoral artery were studied. A total of 181 ultrason ic cross sections were analyzed (94 before and 87 after intervention). Methods and Results: Before intervention intravascular ultrasonograph y distinguished normal cross sections (n = 17) from cross sections wit h a lesion (n = 77): soft (51%) versus hard (31%) lesions, and eccentr ic (75%) versus concentric (7%) lesions. After intervention intravascu lar ultrasonography documented dissection (43%), plaque rupture (10%), and internal elastic lamina rupture (8%). A good correlation between ultrasonography and angiography was found for the recognition of eccen tric or concentric lesions and dissections. The degree of stenosis was assessed semiquantitatively by visual estimation of the degree of lum inal narrowing from the angiograms and intravascular ultrasonic images and was categorized into four classes: (1) normal, (2) less than 50% stenosis, (3) 50% to 90% stenosis, and (4) greater than 90% stenosis. Intravascular ultrasonographic assessment of stenosis was in agreement with angiography in 78% of cases and showed more severe lesions in 22 % before intervention. Similar data were observed after intervention, with 72% of results being in agreement and 28% of cases showing more s evere lesions. The degree of stenosis was also quantitatively evaluate d by computer-aided analysis of the intravascular ultrasonic images. T he semiquantitative analysis by intravascular ultrasonography correspo nded well with the quantitative analysis done by the computer-aided sy stem. When both echography and angiography suggested that arteries wer e normal, quantitative intravascular ultrasonography identified lesion s that occupied an average of 18% of the cross-sectional area of the v essel. Conclusions: This in vivo study shows that intravascular ultras onography is capable of documenting detailed morphologic features. Sem iquantitative ultrasonic data correlate closely with those of angiogra phy, albeit stenoses were assessed as more severe on ultrasonography.