[Computerized tomography: analysis of the characteristics of various pieces of equipment].

Spatial resolution, statistical noise and patient dose are important parameters for the evaluation of the performances of CT-scanners. These parameters may be combined to develope some "synthetic indices", 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 3rd and one of 4th generation.