A method and a workstation are disclosed for visualizing a three-dimensional image data record having a multiplicity of voxels of a heart of a patient, recorded with the aid of an x-ray CT examination carried out with contrast agent present in the bloodstream. In at least one embodiment, the method includes saving the CT image data record including a multiplicity of voxels defined by absorption values, determining the voxels associated with the chamber of the heart by segmenting the chambers of the heart filled with blood containing the contrast agent, removing the image information from the voxels associated with the chambers of the heart, calculating a two-dimensional virtual projection from the remaining CT image data record, and displaying the virtual two-dimensional projection.