Zero-dose C-arm navigation: an efficient approach based on virtual X-ray targeting

The introduction of fluoroscopy based navigation systems has been found to generally result in a significantly reduced amount of radiation dose for the patient as well as the OR-team. These systems enable the virtual projection of surgical instruments inside intraoperative acquired X-ray images. In order to implement this procedure, the position and orientation of the image-intensifier has to be tracked during image acquisition. The spatial information is stored and later used to visualize the tracked position of a navigated tool in relation to the acquired X-ray images. One disadvantage of this method regards the fact that the quality of the X-ray images still depends on the experience of the OR-assistant. To acquire the desired projection view relative to the planes of the body or the correct anatomical areas, the conventional method that is commonly used is "Trial and Error". In difficult cases, the C-arm has to be aligned during permanent radiation in order to find a satisfying projection of the desired anatomical areas. As a consequence, both the patient and the OR-team are unnecessarily exposed to radiation. The zero-dose C-arm navigation addresses this problem by enabling a continuous projection preview without any radiation exposure. A 3D-tracking system is used in order to realize a virtual preview of the anatomical areas during C-arm alignment. In that way, (1) the radiation dose may be further reduced, (2) the quality of image acquisition may be increased which potentially could result in higher surgical accuracy, and (3) intraoperative time may be saved.