Patient doses received during digital subtraction angiography

Digital subtraction angiography (DSA) is based on digital image processing with logarithmic subtraction and edge enhancement. It is used increasingly for the visualization of blood vessels throughout the body. The bulk of the workload in the angiography suite at the Queen Elizabeth Hospital, Birmingham involves carotid and femoral angiograms with other examinations, including hepatic and renal angiograms, being carried out less frequently. A typical examination involves both fluoroscopy and DSA images taken at different projections and different regions of the body. The exposure factors are selected automatically and the ease of image acquisition facilitates the acquisition of large numbers of images -exceeding 100 for some studies. Some examinations, but predominantly femoral angiograms, also involve the use of Puck serial films with the exposure factors being selected manually. The aim of this study was to estimate the effective dose equivalent (International Commission on Radiological Protection, 1977) to patients from complete examinations so that a measure of the risk from the radiation exposure could be evaluated. (Author)