In vivo human comparison of intravascular ultrasonography and angiography

This study evaluates the in vivo correlation of intravascular ultrasonography and uniplanar angiography in determining the luminal dimensions of normal and moderately atherosclerotic human arteries. Five French and 8F rotating A scan intravascular ultrasound catheters were used to obtain 48 images in four superficial femoral arteries, five iliac arteries, and one aorta in eight patients undergoing vascular surgery. Cross-sectional areas measured by intravascular ultrasonography were compared to cross-sectional areas calculated by uniplanar angiography of the same location in the vessel. Maximum and minimum luminal diameters were also measured from intravascular ultrasound images. An ellipticity index was defined as the maximum/minimum diameter ratio (max/min) and ranged from 1.0 to 1.8 (mean, 1.2). Comparison of the cross-sectional areas measured from intravascular ultrasound images and those calculated from uniplanar angiography showed no significant difference at any level of ellipticity studied. However, when the values of cross-sectional areas were analyzed in groups corresponding to the diameter of the vessel, that is, aortic, iliac, and femoral, the values for the iliac arteries calculated from uniplanar angiography were significantly greater by 9.8% ± 0.7% (n = 29, p = 0.03) when compared to those measured by intravascular ultrasonography. In addition to providing accurate luminal determinations, intravascular ultrasound images displayed transmural morphology, the location and character of the atherosclerotic lesions, and the thickness of the vessel wall. We conclude that intravascular ultrasound imaging provides accurate, novel information regarding human vessels and that this technology may play a significant role in future diagnostic and interventional therapies.