Extraction of the C2 transverse foramen with ray-triangle intersection algorithm for screw insertion planning algorithm of cervical spinal surgery

The purpose of spinal fusion surgery is to reduce the pain from the vertebrae by joining two or more vertebrae by using pedicle screws and connecting rods. For the accuracy of surgery, the spinal pedicle screw insertion trajectory algorithm is required to solve this problem. A method is proposed to extract the transverse foramina to define pedicle. Ray-intersection algorithm is applied to vote each viewpoints and only visible facets are voted. The transverse foramen is hidden in the vertebrae body, and its voting score is smaller than other visible facets. The transverse foramen can be extracted by thresholding value of voting score. With extraction, the spinal pedicle screw trajectory algorithm will be developed in the future.