Methods for displaying a vessel with the aid of intravascular ultrasound images and current location and cycle information provided by detectors and sensors. A sequence of intravascular ultrasound images are stored and indexed-by location and by heartbeat and breathing phase. During a subsequent medical intervention, ultrasound images that correspond to the current phase and location of an object of interest such as a catheter can be selected and displayed on a monitor in real time along with an x-ray image of the vessel, the display showing the geometric position of the ultrasound images with reference to the x-ray image.