Detection of Vascular Morphology by High Frequency Intravascular Ultrasonic Imaging

Abstract. This study was designed to validate the potential clinical utility of intravascular ultra-sonic imaging in vitro and in vivo. In vitro studies were performed to assess the accuracy of dimensional and morphological information. In vitro images of human vessels (n = 75) demon-strated that lesion thickness determined echographically closely related with histological samples (r = 0.83). Morphologically, muscular and elastic arteries could be distinguished echographically based on the echogenicity of the arterial media. Close relation was also found in the morphological subtypes of atherosclerosis. Subsequently, intravascular ultrasound was used percutaneously in vivo in 20 patients to obtain images of the iliac and superficial femoral artery. High quality real-time images were obtained. Normal vessels were seen showing pulsatile circular images with a hypoechoic muscular media resulting in a typical three-layered appearance. Diseased arteries revealed non-obstructive and obstructive lumen. At the site of obstruction thinning of the muscular media was evident. Pulsation was not always present. Following dilatation of the obstructive lesion using balloon angioplasty the ultrasonic ross-sections changed rastically revealing plaque rupture, dissection, plaque-free wall rupture, rest stenosis and oedema. We conclude that intravascular ultrasonic imaging is a promising technique to document accu-rate dimensional and morphological characteristics of human vascular disease for guidance of therapeutic interventions