Quantification of the minimal luminal cross-sectional area after coronary stenting by two-and three-dimensional intravascular ultrasound versus edge detection and videodensitometry

The use of 2-dimensional intravascular ultrasound (2-D IVUS) to improve the outcome of coronary stenting has gained clinical acceptance, and recently 3-D IVUS has been introduced to clinical practice. However, there have been no comprehensive studies comparing the measurements of the coronary dimensions after stenting obtained by the different approaches of IVUS and quantitative coronary angiography. We examined the minimal luminal cross-sectional area of 38 stents using 2-D IVUS, 3-D IVUS, and 2 standard methods of quantitative coronary angiography, edge detection (ED) and videodensitometry (VD). Correlations between 2-D IVUS and ED (r = 0.72; p < 0.0001), VD (r = 0.87; p < 0.0001), and 3-D IVUS (r = 0.81; p < 0.0001) were higher than the correlations seen between 3-D IVUS and ED (r = 0.58; p < 0.0005) and VD (r = 0.70; p < 0.0001). The measurements by 2-D and 3-D IVUS (8.32 ± 2.50 mm2 and 8.05 ± 2.66 mm2) were larger than the values obtained by the quantitative angiographic techniques ED and VD (7.55 ± 2.22 mm2 and 7.27 ± 2.21 mm2). Thus, concordance was seen among all of the 4 techniques, confirming the validity of using IVUS for determination of the minimal luminal cross-sectional area after coronary stenting. A particularly good correlation was found between VD and IVUS, perhaps because measurement of the luminal area is the basic quantification approach of both techniques, whereas the lower correlations of ED with IVUS and VD may be explained by the dependence of ED on the angiographic projections used, which is especially important in eccentric stent configurations.