Adaption of the Quality Criteria Concept to Digital Radiology

• Published in: Radiation protection dosimetry Vol. 80; no. 1-3; pp. 61 - 63
• Main Authors: Busch, H.P., Jaschke (INVITED), W.
• Format: Journal Article
• Language: English
• Published: Oxford University Press 01.11.1998
• DOI: 10.1093/oxfordjournals.rpd.a032543
• ISSN: 0144-8420

In recent years conventional film-screen radiography has been more and more replaced by digital techniques like 'Digital Image Intensifier Radiography' and 'Digital Storage Phosphor (Selen) Radiography'. These new digital imaging methods can be used for all areas of radiography except mammography. Digital radiography offers the advantage of additional diagnostic information, digital image format, lower radiation risk to the patient and a favourable cost/benefit relation. With digital techniques, dose can be varied over a wide range without losing diagnostic information. Thus, dose can be reduced in comparison to film-screen radiography. Inadequate technique can, in certain applications, however, lead to a significant increase of dose. Therefore, special reference dose values have to be established and controlled continuously. Different possibilities of pre- and post-processing make the evaluation of image quality of digital technique more complex compared with conventional film-screen radiography. New parameters like signal to noise ratio are more appropriate in assessing image quality. However, in daily routine well known parameters like spatial resolution, contrast detectability and dose can be more easily used for the assessment of image quality of the whole imaging chain including image processing and documentation. Special guidelines for digital radiography are necessary to guarantee high image quality and to avoid overexposure and misdiagnoses. These guidelines should be based on the Quality Criteria Concept of the EC. They should include criteria for the detectability of specific anatomic details, technical parameters for good radiographic technique and imaging performance and reference dose values. Assessment of image quality by suitable phantoms and constancy testing are prerequisites for quality assurance. The activities of an European quality criteria working group in the 'Concerted Action Programme' are focused on these subjects.