A medical viewing system for displaying a sequence of images of a medical intervention that comprises moving and/or positioning a tool in a body organ, which tool is carried by a support to which at least one marker is attached at a predetermined location with respect to the tool, comprising means for acquiring the sequence of images, and for processing said images during the medical intervention, wherein: extracting means for automatically extracting at least one marker that is attached to the tool support and that neither belongs to the tool nor to the body organ, and yielding the marker location information; computing means for automatically deriving the tool location information from the marker location information, and enhancing means for improving the visibility of the tool and/or the body organ in order to check whether the medical intervention stages are successfully carried out.