Aliasing in CT [computed tomography] images is the result of discrete sampling the 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 was studied in simulation with a phantom designed to represent a transaxial section through the lower [human] head. Although the simulation program assumes a stationary detector system, the results do not depend strongly on geometry. Aliasing was also compared with other sources of artifact which are often more significant, such as beam hardening, machine alignment and noise.