Coronary angiography: an analysis of radiographic practice in the UK.

There is growing public and professional concern over the risks of medical ionizing radiation. It is therefore important to examine our procedures for ways in which we can reduce radiation dose to patients and staff. We surveyed 48 catheter laboratories nationwide to establish the range of practice in performing "routine" coronary angiography and left ventriculography. There were wide variations in the numbers of views obtained, mean ciné film lengths and mean fluoroscopy times. Despite the recommendation of the National Radiological Protection Board, only five of the 36 centres responding were able to provide estimates of patient radiation dose per procedure. Calculations of maximum and minimum patient doses, based on ciné film length and fluoroscopy time, show a fourfold variation between hospitals. Using the concept of estimated dose equivalent, the predicted lifetime fatal cancer risk for a routine examination ranges from 1/16,600 to 1/4300. As a preliminary step in radiation dose reduction we have used this survey data to suggest how a typical coronary angiogram and left ventriculogram might be performed.