Characterization of arterial plaque using intravascular ultrasound: In vitro and in vivo results

Intravascular ultrasound is commonly used to image arteries before and after percutaneous procedures to restore blood flow in vessels where plaque has reduced the size of the vessel lumen. There is growing evidence that the success of such procedures depends on the composition of the plaque. In this study, this problem has been addressed by applying tissue characterisation techniques to intravascular ultrasound data obtained from a set of in vitro specimens of known pathology using a radiofrequency data acquisition system interfaced to a commercial intravascular scanner. We found that the attenuation slope of plaque is significantly increased in areas of nonfibrous plaque. This increase in attenuation slope is sufficiently high to allow it to be parametrically imaged and combined with gray‐scale imaging as a color overlay. Comparison with histologic sections shows that nonfibrous plaque can be detected even when it is not visible on the gray‐scale image. In addition, specular reflections may be readily distinguished from calcifications. Limited in vivo studies are consistent with the hypothesis that there is a relationship between plaque dissection and areas (probably calcification) detected by this method. © 1997 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 8: 52–60, 1997