Time-Dependent Three-Dimensional Intravascular Ultrasound

Intravascular ultrasonography and x-ray angiography provide two complimentary techniques for imaging the moving coronary arteries. We present a technique that combines the strengths of both, by recovering the moving three-dimensional arterial tree from a stereo pair of angiograms through the use of compound-energy ‘snakes’, placing the intravascular ultrasound slices at their proper positions in time and space, and dynamically displaying the combined data. Past techniques have assumed that the ultrasound slices are parallel and that the vessel being imaged is straight. For the first time, by applying simple but effective techniques from computer graphics, the moving geometry of the artery from the angiogram and the time-dependent images of the interior of the vessel wall from the intravascular ultrasound can be viewed simultaneously, showing the proper geometric and temporal relations of the slice data and the angiogram projections. By using texture mapped rectangles the combined ultrasound slice/angiogram display technique is well suited to run in real time on current graphics workstations.