Picture quality of computed tomography.

Some limitations that impair the picture quality of computed tomography are presented. Picture grain is analyzed in detail and its relationship to different matrix sizes is demonstrated. The choices of matrix size for viewing various parts of the body are defined, and the need for higher resolution in the future is debated. Comparison is made between two scanning systems: the moving fan beam with rotation and the simple rotating fan beam. Possible artifacts in the picture caused by drift and delay in dector response are discussed.