A study of noise and spatial resolution for 2D and 3D filtered backprojection reconstruction

We present an analysis of the benefits of distance-driven backprojection when used as part of a filtered backprojection reconstruction algorithm, and a comparison with pixel-driven backprojection. We simulated phantoms to quantify image noise and spatial resolution, and performed reconstruction using 2D fan-beam FBP and 3D FDK reconstruction. After matching the resolution for pixel-driven and distance-driven for each region, distance-driven driven backprojection resulted in up to 20% noise reduction relative to pixel-driven backprojection at matched spatial resolution, for a 42 cm/spl times/28 cm elliptical water phantom.