A survey of patient dose and image quality for computed tomography scanners in Wales.

The main aim of the study was to assess the current level of radiation dose from computed tomography scanning in the NHS in Wales and to compare these results with previous studies in Wales and the UK. In addition, the relationship between patient dose and image quality was investigated by comparing mean patient dose calculations with image noise using two quality assurance (QA) phantoms. The results show that although the introduction of spiral scanners has reduced the dose per examination, the collective dose per scanner has actually increased. The results also highlight the potential for relating dose and objective measures of image quality to assist in the selection of scanning parameters to optimise dose without compromising image quality.