| 主权项 |
1. A method for generating a virtual radiograph for display on a display device, comprising:
providing an image generation system having a processing circuit including a processor and a memory device, the image generation system coupled to the display device; retrieving three-dimensional image data of an anatomy stored in the memory; retrieving a three-dimensional bone model corresponding to a portion of the anatomy stored in the memory; associating the three-dimensional bone model with the three-dimensional image data such that the three-dimensional bone model defines first boundary containing a first bounded volume within the three-dimensional image data corresponding to the portion of the anatomy; and performing a volume ray casting process on the three-dimensional image data, the process comprising:
casting a ray from an origin point through a first pixel in a screen space rectangle, and through the first bounded volume;sampling the first bounded volume at a plurality of sampling steps along the ray, the sampling steps separated by a sampling distance, wherein the sampling is limited to a segment of the ray between a position proximate to a front facing intersection of the ray and the first boundary, and a position proximate to a back facing intersection of the ray and the first boundary;computing an attenuation coefficient of the ray at each of the sampling steps based upon the sample at each of the sampling steps;calculating a first accumulated attenuation value of the first bounded volume along the ray;casting a second ray along a second pixel of the screen space rectangle;repeating the sampling, computing, and calculating steps for the second pixel of the screen space rectangle to calculate a second accumulated attenuation value of the first bounded volume; andstoring the accumulated attenuation values of the first bounded volume. |
