A method is provided for creating a volume graphic via a catheter for introduction into a vessel which has an ultrasound unit, which is embodied to transmit ultrasound, to measure an echo of the transmitted ultrasound, and to create image data for a two-dimensional cross-section of the vessel on the basis of the measured echo. The method involves creating image data of a cross-section with the ultrasound unit at a plurality of different positions on a movement track of the catheter, and, in addition to the image data, creating position data for the current position of the ultrasound unit with a localization device. The method further involves creating the volume graphic from the image data of all cross-sections in which the cross-sections are arranged relative to one another in accordance with the position data.
