Radiation exposure from conventional and digital subtraction angiography of cerebral vessels

Patients with atherosclerotic cerebrovascular disease were studied to determine the radiation exposure associated with conventional and digital subtraction angiography of the cerebral vessels. The median exposure-area product was 3198 R cm2 (range, 616-5665 R cm2) in the conventional angiography group and 1831 R cm2 (range, 366-4198 R cm2) in the IV digital subtraction angiography (DSA) group. This difference in exposure resulted from increased use of fluoroscopy in the conventional screen-film angiography group. The actual difference in exposure between the radiographic and digital imaging portions of the examinations was much smaller. The contributions of fluoroscopy to the radiation exposure in conventional angiography and IV-DSA in this study were 37% (range, 8.8-76%) and 6% (range, 1.5-25%), respectively.