QUANTITATIVE-ANALYSIS OF CORONARY DYNAMICS BY TIME-DEPENDENT ULTRASOUND IMAGING

Intravascular ultrasound imaging is a new technique that displays info rmation on lumen and arterial walls, and is capable of providing real- time monitoring of cross-sectional high-resolution images. This techni que has potential application for studying the dynamics of the arteria l wall with respect to the presence or absence of pathology and the va scular response to physiological or pharmacological stimuli. Although the extraction of information related to coronary dynamics and wall pa thologies is possible by manual procedures, it is very time consuming and influenced by intra- and interobserver errors. We developed an eva luation system for analyzing 3-D spaces defined by digitized cross-sec tional ultrasound images of coronaries quantifying the vasomotion in r elation to the morphology of the arterial wall. Sequences of echograph ic images were obtained and recorded as ordered stacks of 2-D frames o n a VHS videotape. For each image, an automatic lumen edge segmentatio n was performed, then 3-D reconstruction was obtained to evaluate time -dependent lumen and vessel wall changes. These 3-D representations se rve to demonstrate dynamic phenomena and to perform quantitative analy ses (e.g., area/hemidiameter variations, projections, sections, ''carv ing'' etc.).