1. A method for improving visibility and supporting automatic detection and tracking of interventional tools which are to be applied in the scope of minimally invasive X-ray guided interventions, said method comprising the steps of calculating (S 6 ) differences between 2D projected image data of a preoperatively acquired 3D voxel volume showing an anatomical structure or region of interest, pathological abnormalities, pacemakers and/or other medical implants in a tissue of a patient's body to be examined or in a blood vessel segment of said patient's vascular system and intraoperatively recorded 2D fluoroscopic images showing the aforementioned objects as well as interventional tools which have been introduced into the interior of said patient's body, wherein said 2D fluoroscopic images have been co-registered (S 4 ) with the 2D projected image data, and using the resulting difference image that is generated based on said calculation step for enhancing (S 7 a, b ) the contrast and visibility of interventional tools inserted into said tissue region or said blood vessel segment by removing common patterns detrimental to the visibility of the interventional tools, said patterns being contained both in the 2D projection image of the preoperatively acquired 3D voxel volume and in the intraoperatively recorded 2D fluoroscopic images.