Interactive GPU-accelerated image reconstruction in cone-beam CT

We offer a novel approach for real-time CT reconstruction with the possibility of interactively changing parameters like the position and orientation of the slice to arbitrary values by the user during the analysis. To achieve this, a new reconstruction, including backprojection, is done every time the user wants to see a different view (in contrast to computing a volume upfront). The reconstruction was implemented on a GPU (graphics processing unit) using OpenGL and provides near real-time performance with less than 20 ms reconstruction time for 512 × 512 images. With this approach the user is free to change parameters that are fixed when a conventional reconstruction is used. So he is free to set the position of the slice, its orientation and the voxel size to arbitrary values, or to select a different set of projections for a cardiac reconstruction. Thus the waiting time for the volume reconstruction is removed. Therefore our method is esp. promising for applications such as intra-operative CT and interventional CT.