METHOD FOR DETECTING THE THREE-DIMENSIONAL POSITION OF AN EXAMINATION INSTRUMENT INSERTED INTO A BODY REGION

A method for detecting the three-dimensional position of an examination instrument inserted into a body region, on which instrument there are provided three markings whose mutual geometric arrangement is known, by using a device for recording radiation images with the aid of a radiation source and a radiation receiver, includes the steps of, recording two-dimensional projection image of the body region, determining the positions (ui, vi) of the three markings in the projection image, and determining the spatial coordinates (xi, yi, zi) of the three markings in the coordinate system of the recording device with the aid of the positions (ui, vi) and the projection matrix belonging to the projection image, taking into account the known mutual geometric arrangement of the markings.