Monte Carlo Based Reconstruction Using A Rotator for 2-D PET Data

Accurate system modeling is normally performed through the System Matrix (SM) in Positron Emission Tomography (PET). The SM can be calculated analytically or by Monte Carlo (MC) methods. MC methods model detector response precisely and lead to better image quality when used in a statistical reconstruction method[1]. However,for modern human PET scanners, two problems hinder the use this method. The first problem lies in the storage of the huge SM. The second problem is the intensive computational load in simulating the SM. We used a Gaussian rotator [2] to solve these problems. With the rotator, both the SM storage and SM simulation requirement is greatly reduced (proportional to the number of scanner blocks) without loss of image quality.