Assessment of coronary plaque with optical coherence tomography and high-frequency ultrasound

This study compares the ability of intravascular optical coherence tomograp hy (OCT) and high-frequency intravascular ultrasound (IVUS) to image highly stenotic human coronary arteries in vitro. Current imaging modalities have insufficient resolution to perform risk stratification based on coronary p laque morphology. OCT is a new technology capable of imaging at a resolutio n of 5 to 20 mu m, which has demonstrated the potential for coronary arteri a! imaging in prior experiments. Human postmortem coronary arteries with se verely stenotic segments were imaged with catheter-based OCT and IVUS, The OCT system had an axial resolution of 20 mu m and a transverse resolution o f 30 mu m. OCT was able to penetrate and image near-occlusive coronary plaq ues, Compared with IVUS, these OCT images demonstrated superior delineation of vessel layers and lack of ring-down artifact, leading to clearer visual ization of the vessel plaque and intima, Histology confirmed the accuracy a nd high contrast of vessel layer boundaries seen on OCT images. Thus, cathe ter-based OCT systems are able to image near-occlusive coronary plaques wit h higher resolution than that of IVUS, (C)2000 by Excerpta Medico, Inc.