The present invention relates to minimally invasive X-
ray guided interventions, in particular to an 
image processing and rendering 
system and a method for improving 
visibility and supporting automatic detection and tracking of interventional tools that are used in electrophysiological procedures. According to the invention, this is accomplished by calculating differences between 2D projected image data of a preoperatively acquired 3D 
voxel volume showing a specific anatomical 
region of interest or a 
pathological abnormality (e.g. an intracranial 
arterial stenosis, an 
aneurysm of a cerebral, pulmonary or coronary 
artery branch, a 
gastric carcinoma or 
sarcoma, etc.) in a tissue of a patient's body and intraoperatively recorded 2D fluoroscopic images showing the aforementioned objects in the interior of said patient's body, wherein said 3D 
voxel volume has been generated in the scope of a 
computed tomography, 
magnet resonance imaging or 3D rotational 
angiography based 
image acquisition procedure and said 2D fluoroscopic images have been co-registered with the 2D projected image data. After registration of the projected 3D data with each of said X-
ray images, comparison of the 2D projected image data with the 2D fluoroscopic images—based on the resulting difference images—allows removing common patterns and thus enhancing the 
visibility of interventional instruments which are inserted into a 
pathological tissue region, a 
blood vessel segment or any other 
region of interest in the interior of the patient's body. Automatic 
image processing methods to detect and track those instruments are also made easier and more robust by this invention. Once the 2D-3D registration is completed for a given view, all the changes in the 
system geometry of an X-
ray system used for generating said fluoroscopic images can be applied to a registration matrix. Hence, use of said method as claimed is not limited to the same X-ray view during the whole procedure.