Dose-area product of patients undergoing digital subtraction angiography (DSA): abdominal aorta and lower limb examinations.

Complex analysis of the fluoroscopy time, exposure time, air kerma values and dose-area product (DAP) has been carried out for a very large group of patients (655) undergoing digital subtraction angiography (DSA) for abdominal aorta and lower limb examinations. Measurements have been performed for 206 patients with intravenous (IV DSA) and 449 patients with intra-arterial (IA DSA) contrast administration. The results obtained by the two variations of the DSA technique have been compared. Median DAP values for fluoroscopy are 5.4 (IA DSA) and 3.2 (IV DSA) Gy cm and for exposure are 51.7 and 66.3 Gy cm2, respectively. A good correlation between the exposure time and DAP has been found for the two types of examinations: IA DSA (r = 0.78) and IV DSA (r = 0.8). However, the correlation of fluoroscopy time and DAP has been insignificant, and the correlation coefficient is 0.39 for IA DSA and 0.63 for IV DSA. The DAP and the time exposure ratio have been significant factors differentiating these two methods. In fluoroscopy patients obtained higher doses in IA DSA, while in exposure doses were higher in IV DSA. Measurements of DAP can be a simple and accurate method for estimation of the stochastic radiation risk to the patients.