Data analysis from a multi-centre, comparative study of angiographic examinations leading to practical guidelines for the optimisation of patient doses.

In this study, patient doses were analysed against exposure parameters and procedure protocol. Patient doses were measured in seven hospitals for a standard diagnostic vascular examination. Image quality was assessed using the contrast-detail phantom from Nijmegen (CD-DISC 2.0). A link between dose and image quality was investigated. Image quality strongly depends on the preset dose level. The higher the dose level, the better the image quality, but also the higher the patient dose. However, no clear correlation was found between total dose-area product (DAP) or effective dose and image quality. A large range in patient dose was found: DAP (22-130 Gy cm2) and effective dose (3.9-16.8 mSv). A difference in number of frames was also found in the different centres, owing to different frame rates (3-2-1 frames per second) and use of oblique projections. Differences in doses and exposure settings offer the possibility of optimising patient doses in angiography and interventional radiology.