Validation of a novel wire-type intravascular ultrasound imaging catheter.

Intravascular ultrasound can be used to characterize atherosclerotic plaques in arteries. This report describes the results of in vitro experiments with a novel wire-type intravascular ultrasound-imaging catheter developed in our laboratory. The ultrasound catheter comprises a 30-MHz transducer mounted on the tip of a wire-type catheter. The outer diameter of the catheter at the distal acoustic site was 0.025". Dimensional measurements of arteries obtained at the time of autopsy were acquired by intravascular ultrasound and direct planimetry. The luminal CSA (cross-sectional area), vessel CSA, and intima-media thickness for arterial samples (n = 22) acquired by ultrasound images and histopathologic microsections correlated closely (r = 0.99, 0.97, and 0.99, respectively). The histopathologic lumen CSA, vessel CSA, and intima-media thickness were less than those of corresponding ultrasound images in 43 of 54 samples (80%), 43 of 54 samples (80%), and 62 of 62 samples (80%), respectively. Intraobserver and interobserver variances of the luminal CSA vessel CSA and intima-media thickness by ultrasound images were excellence. This novel wire-type intravascular imaging catheter provides accurate vessel measurements and plaque thickness. Furthermore, this intravascular imaging catheter can be used in coronary arteries to assess the morphology of small distal coronary arteries.