CT scanner comparison.

A survey of six production CT scanners in clinical use has been carried out. The scanner types are the ACTA 0200, EMI 1007, EMI 5005, GE 7800, DELTA 2010, and the AS & E 500. Measurements were made of the noise, spatial resolution, edge enhancement, axial position sensitivity, artefact, and dose. Dose is expressed in terms of the total absorbed energy or the volume integral of the dose, as this is considered the factor most directly related to patient risk. A relationship between dose and picture quality parameters is developed and applied to the scanners for a wide range of settings. Particular emphasis has been placed on evaluting the different operating modes of each scanner. The results show a great variation between machines, especially in the relationship between resolution and noise, and the performance achieved for the dose delivered.