Respiratory Motion during the scan causes motion artifacts, in order to reduce these artifacts here is an algorithm called Pixel-specific back projection. PSBP is an approximate filtered back-projection algorithm that corrects for in-plane motion by performing the reconstruction using a coordinate system that is specific to each pixel. To reduce artifacts caused by respiratory motion in chest CT scans, an algorithm called pixel specific back-projection (PSBP) has been developed. PSBP is an approximate filtered back-projection algorithm that corrects for in-plane motion by performing the reconstruction using a coordinate system that is specific to each pixel. The coordinate systems move according to the in-plane motion in the slice at the time the projection was acquired. PSBP reduced artifacts caused by motion in both simulated and patient scan data.The coordinate systems move according to the in-plane motion in the slice at the time the projection was acquired. Depending on the intensity of the pixels this algorithm works.