An Improved Low Dose Simulation Method for CT

We present a new low dose simulation method in the projection space of CT data which allows any general electronic noise model. In particular, the model for electronic noise is not restricted to have zero mean. Poisson and Gaussian noise are added to higher dose projection data in such a way as to properly account for the mean and variance of the resulting lower dose signal. The accuracy of the simulation in the very low dose limit is restricted only by the accuracy of the electronic noise model used. The method is well defined over the full dose ratio range 0 ≤ r ≤ 1. Results are demonstrated by comparing real and simulated water equivalent phantom data.