Image quality and dose in computerized tomography: evaluation of four CT scanners.

Spatial resolution, statistical noise, and patient dose are important parameters for the evaluation of the performances of computerized tomography (CT) scanners. These parameters are combined to develop some "synthetic indices," and to be able to describe intrinsic properties of a CT scanner (the maximum obtainable spatial resolution and dose efficiency). This type of analysis has been applied to the evaluation of four CT scanners, three of third, and one of fourth generation.