Abstract: The development of image reconstruction in computed tomography (CT) remains one of the most active areas in modern imaging sciences. In the last few years, there have been significant breakthroughs in the development of mathematically exact and innovative methods for image reconstruction from parallel-beam, fan-beam and cone-beam projection data. This paper introduces a type of BPF-based algorithms proposed by the laboratory led by Dr. Xiaochuan Pan at The University of Chicago. One of important properties of the BPF-based algorithms lies in that it can provide exact image reconstruction within a region of interest (ROI) from projection data containing longitudinal and transverse truncations. Such a unique property of the BPF-based algorithm offer the opportunity to design targeted ROI-imaging strategy, thus reducing scanning effort, computation time, radiation dose, and imaging artifacts such as scatter.