3-DIMENSIONAL INTRAVASCULAR ULTRASOUND IMAGING OF NORMAL AND DISEASED CANINE AND HUMAN ARTERIES

This study reports three-dimensional reconstruction of two-dimensional intravascular ultrasound images obtained along 5 cm vessel segments. Each three-dimensional image was produced by computerized "stacking" of a set of consecutive two-dimensional images (mode 90 images per set; range 32 to 256). Three-dimensional images (n = 26) were obtained from 11 human normal and atherosclerotic arteries (three in vitro and eight in vivo) and five in vivo canine studies. In vivo human examinations included three iliac, one deep, and three superficial femoral arteries and one aortic dissection. Five in vivo canine vessels (three iliac stenoses and two aortic dissections) were imaged before and after intraluminal stent deployment. Images were displayed on a gray-scale monitor, allowing examination of vessel images as complete cylinders or longitudinal hemisections in any user-defined plane. This enabled global examination of vascular segments and identified luminal shape, wall thickness, and distribution and morphology of plaques. Reconstructions of aortic dissections illustrated the extent of the dissection and produced an anatomic picture of the false lumen. Three-dimensional imaging enhanced stent deployment by identifying the site for deployment, dimensions of the vessel lumen, and changes in morphology after stent insertion. There was good correlation in vessel dimensions measured by angiography, two-dimensional intravascular ultrasonography and longitudinal gray-scale reconstructions (r = 0.74 to 0.95; p = 0.34 to 0.001) but poor correlation with measurements from three-dimensional surface-rendered images (r = 0. 13 to 0.48; p = 0.42 to 0.87). We conclude that three-dimensional intravascular ultrasound imaging is an innovative new method for identifying the type, extent, and spatial configuration of arterial disease, with promising diagnostic and therapeutic applications.