Measurement of image quality in diagnostic radiology.

The aim in radiology is to obtain images which are adequate for the clinical purpose with the minimum radiation dose to the patient. If optimum performance is to be achieved, assessments of image quality must be made to balance against patient dose. The subjective nature of image interpretation makes an objective approach to such assessment difficult. Methods widely applied involve the use of test objects, which although providing a measure of imaging performance may be difficult to link to clinical image formation. The ideal method for evaluation of imaging techniques is through clinical trials and this should be used to address major questions. Scoring of quality criteria, relating to features observed in a normal clinical radiograph, provides a simple method through which image quality can be assessed in every hospital department.