Backprojection in CT is the heart of both Filtered Backprojection and Iterative Reconstruction which are the only two ways used clinically today to generate images in CT. Interpolation is a key step and one that Radiologic Technologists often struggle with as there are some mathematical concepts involved.
In this video we cover the Backprojection process in detail and the fact that linear interpolation is no more complicated than drawing a line and moving down that line a little in the direction determined by the slope of the line.
Finally, we cover interpolation in CT and why for high resolution imaging it is crucial to use a small DFOV (display field of view) such that the interpolation occurs primarily on the CT detector and not in the image space.