THE IMPACT OF CARDIOLOGY ON THE COLLECTIVE EFFECTIVE DOSE IN THE NORTH OF ENGLAND

Two cardiology X-ray rooms were monitored with dose-area product meter s as part of a Regional Patient Dosimetry Programme. Dose-area product measurements on over 2000 patients undergoing examinations in the car diology rooms are presented. The data have been corrected according to patient size where possible. In room A mean dose-area product values for coronary angiography, coronary angioplasty, radiofrequency ablatio n and mitral valvuloplasty were found to be 47.7, 72.2, 91.1 and 161.9 Gy cm(2) respectively. In room B mean dose-area product values for co ronary angiography and coronary angioplasty were found to be 23.4 and 51.6 Gy cm(2) respectively. Observational studies were used to deduce the typical projections and technique factors. This typical examinatio n was used to simulate an angiogram from which it was possible to deri ve factors to convert measured dose-area product values into estimates of effective dose. In room A: the effective doses were estimated to b e 9.4, 14.2, 17.3 and 29.3 mSv for coronary angiography, coronary angi oplasty, radiofrequency ablation and mitral valvuloplasty, respectivel y. The effective doses during coronary angiography and coronary angiop lasty, performed in room B, were found to be 4.6 and 10.2 mSv, respect ively. A regional survey of the frequency of these cardiac procedures was performed. It was deduced that the annual collective effective dos e from these cardiac procedures in the North of England, the former No rthern Region, was 45.7 manSv.