Aliasing in CT images is the result of discrete sampling in the data-taking process. Artifacts associated with aliasing, while object-dependent, also depend on fundamental parameters such as beam width and the number of rays and views. This dependence has been studied in simulation with a phantom designed to represent a transaxial section through the lower head. Although the simulation program assumes a stationary detector system, the results do not depend strongly on geometry. Aliasing has also been compared with other sources of artifact which are often more significant, such as beam hardening, machine alignment and noise.