Patient dose in cardiac radiology.

Abstract

INTRODUCTION: In diagnostic and interventional cardiology procedures performed with the use of X-ray diagnostic imaging systems, the long fluoroscopy time and the large number of cine projections, as well as the repetition of the procedure due to the recurrence of the lesion--a common event--result in a high locally delivered skin dose, which may even lead to patient skin necrosis. The purpose of this study was to collect information in order to estimate the patient dose during coronary angiography and coronary angioplasty procedures, using the dose-area product measuring system of the X-ray angiographic machine. METHODS: Dose-area product (DAP), fluoroscopy time, number of sequences and frames per sequence were collected for each of 108 coronary angiography and 101 coronary angioplasty procedures, using the dedicated X-ray machine of the hospital's haemodynamic department, where more than 3000 procedures are performed per year. RESULTS: The median values of DAP were 19.96 and 40.17 Gy.cm(2) for coronary angiography and angioplasty, respectively; fluoroscopy times were 7.7 and 23.4 minutes; and the numbers of frames were 457 and 641, respectively. There was a strong correlation between DAP and fluoroscopy time, the number of frames per sequence, and hence the cine recording time. CONCLUSIONS: The entrance skin dose delivered to the patient in the haemodynamic department was lower than that of other studies, although the mean fluoroscopy time per patient was longer. The practices in use satisfy the diagnostic reference levels as far as DAP values and number of frames per patient are concerned, but not with regard to fluoroscopy time. We did not find the correlation between doctors' experience and DAP values reported in other studies, as we did not take into account the complexity index of the lesion.