Real-time GPU implementation of a weighted filtered back-projection algorithm for stationary gantry CT reconstruction

We present details of a real-time implementation of a new algorithm designed to reduce streak artifacts in switched-source stationary gantry CT reconstruction. The algorithm is of the filtered back-projection type, and uses a voxel-specific weighting function to account for the non-uniform distribution of illumination angles caused by such a scanning geometry. The main challenge in developing a real-time implementation is the storage and memory bandwidth requirements imposed by the weighting function. This has been addressed by storing weights at a low precision and reduced resolution, and using interpolation to recover weights at the full resolution. Results demonstrate real-time performance of the algorithm at a realistic problem size, running on a low-cost consumer grade laptop.