Patient doses during digital subtraction angiography of the carotid arteries: comparison with conventional angiography.

Radiation doses were compared in 97 patients undergoing conventional film/screening angiography and digital subtraction angiography (DSA) for the evaluation of carotid disease. The results indicate a twentyfold reduction in the radiation dose to the bone marrow and lens of the eye and a tenfold reduction in thyroid dose with DSA. The physical basis for the reduction is smaller field size and less fluoroscopy. With DSA the number of patients examined for carotid disease can increase by a factor of approximately 20 without any increase in the population dose.