The principles of quality assurance and quality control applied to both equipment and techniques

QA is a management technique that, in diagnostic radiology, should be carried out to ensure the production of high quality diagnostic images for the minimum patient radiation dose. It will require a quality control programme involving the selective testing of each major system component on a regular basis. The major systems in diagnostic radiology concern X-ray production, X-ray detection, image processing and image viewing. For a given system, there are many possible variables that might be monitored, and it is important to balance the potential dose savings against the cost of monitoring. In the case of X-ray production, for example, it may be adequate to confine regular testing to AEDs, radiographic output and beam alignment, once the initial checks have been performed. A QA programme should also include a film reject analysis. In nuclear medicine, the QA programme should include checks on the dose calibrator as well as checks on the gamma cameras used for imaging. (Author)