Image quality in vascular radiology and the link with patient dose

In view of the recommendations of the European Directives, patient doses were determined for some vascular examinations in different Belgian hospitals. Keeping doses as low as possible for such complex procedures, without jeopardizing image quality (IQ), is not straightforward. In this study, IQ was evaluated and a link with patient dose was investigated. We used a contrast-detail phantom (CD-DISC 2.0) for the assessment of IQ, representing low-contrast and resolution in an image. Digital acquisition images were taken of the phantom in different hospitals. IQ was determined in terms of a contrast-detail (CD) curve and in terms of the Image Quality Figure (IQF). We observed a clear linear correlation between IQ and the doselevel at the image intensifier. No correlation could be observed between IQ and tube voltage. Comparing our CD-curves with standard curves, we could conclude that any differences were due to differences in doselevel at the II. IQ could be evaluated and the most influencing parameter is the dose/image at the II. However, the circular CD-holes in the test object offer a poor approximation of the real clinical situation. There is the need to investigate real diagnostic quality of images.