Fast 3D Iterative Reconstruction of PET Images Using PC Graphics Hardware

Using iterative reconstruction algorithms in 3D positron emission tomography (PET) studies produce images with superior quality, however the run time is too long for these algorithms to be used routinely, especially for dynamic studies. Recently several new hardware architectures are available to speedup 3D iterative reconstructions, including the graphics processing unit (GPU), which is very attractive due to its fast performance improvement and low cost. In this study, we investigate the possibility of implementing fast iterative 3D PET reconstruction using commercial graphics hardware. A 3D ordered subset expectation maximization (OSEM) algorithm was implemented and a GPU used to calculate the geometric forward and back projections using a line-integral model. Results show that the GPU can be used for fast 3D iterative PET image reconstructions. Future work would include exploring the possibility of implementing more accurate geometric models on the GPU.