1. A method for displaying a patient's vessel and an object of interest in real time during a medical intervention in the patient, the method comprising the steps: a) recording and storing in a physical memory in a run-up previous to the medical intervention a sequence of intravascular ultrasound vessel cross section images of the vessel from an intravascular ultrasound pull back sequence; b) recording and storing in the same physical memory angiograms of the vessel obtained from an x-ray device while injecting contrast agent; c) indexing the ultrasound vessel cross section images and angiograms at the time of their recording by respective locations of their recording in the vessel; d) indexing the ultrasound vessel cross section images and angiograms at the time of their recording by respective values of a cyclic heartbeat of the patient's heart; e) indexing the ultrasound vessel cross section images and angiograms at the time of their recording by respective values of a cyclic breathing of the patient; f) detecting a current location in the vessel of the object of interest in real time during the medical intervention using an x-ray or NMR (nuclear magnetic resonance) image device to provide a current location image; g) detecting a current value of the cyclic heartbeat using an electrocardiogram; h) detecting a current value of the cyclic breathing using a breathing sensor, and recording the current values of the cyclic heartbeat and the cyclic breathing along with the current location image; i) selecting three or more ultrasound vessel cross section images from the sequence of stored ultrasound vessel cross section images, wherein the selected images have locations of their recording that lie within the current location image and have the same current values of the cyclic heartbeat and the cyclic breathing as the current location image; and j) displaying the selected ultrasound vessel cross section images concurrently with the current location image or a stored angiogram corresponding to the current location image, showing the locations of the recording in the vessel of each of the selected ultrasound vessel cross section images with reference to the current location image or stored angiogram with symbols.