Digital coronary angiography: the new gold standard?

Digital coronary angiography: the new gold standard? Few, if any, other areas of imaging require the high spatial, temporal, and contrast resolutions that are needed for coronary arteriography. For two decades 35 mm cine-angiography has fulfilled these requirements and has been regarded as the "gold standard" for the investigation of coronary artery disease; but despite its many advantages cine film has some drawbacks. Satisfactory film processing requires very careful attention to detail and is generally carried out after procedures are completed (a particular problem in some interventional procedures). Storage offilm can occupy considerable space, contrast medium and radiation dosages are relatively high, and, above all, no quantitative analysis or image manipulation is possible. Digital angiography was being developed as early as 1975' and is now well established in non-cardiac angiography. Cine angiography, however, remained unchallenged as the imaging technique of choice for coronary artery studies right through the early development period of digital angiography whose potential for coronary imaging has only been recognised within the past few years.23 Now that most major manufacturers of diagnostic x ray equipment are offering commercially competitive digital cardiac imaging equipment the question increasingly being asked is "Has digital imaging become the new 'gold standard' for coronary angiography?" Overcoming limitations Early attempts at digital coronary angiography used systems developed for peripheral angiography. Although their performance was adequate for peripheral angiography, the speed of image acquisition (up to eight frames per second), matrix size (initially 2562), limited digital data storage (early digital discs were unable to hold even one patient's set of coronary angiograms), and the lack of adequate archiving made digital coronary angiography a cumbersome and inadequate examination. Imaging by continuous fluoroscopy with suboptimal radiographic variables produced very noisy images with much motion artefact and this severely restricted the capabilities of early systems. Technical developments occurred with increasing rapidity in the past decade and by 1985 digital cardiac imaging had progressed to a point where its potential was becoming clear. Dedicated cardiac digital systems were found to be of particular use in the study of congenital heart disease' where the demands for spatial resolution were not quite as high as for coronary studies. It was clear that the ability to manipulate digital data had major potential advantages, not only by increasing contrast sensitivity and permitting instant subtraction techniques but also by allowing much easier quantitative analysis and other manipulation of the angiographic data. It was …