CT ANGIO NECK & BRAIN VESSELS

\N

With increasing usage of computed tomography angiography (CTA) in recent years, more and more attentions have been paid to the potential risk of cancer related to radiation exposure during the procedures, especially to those patients who have chronic diseases and have to undergo examinations frequently for continuous treatment and monitoring . In order to reduce this risk, the radiation dose should be kept as low as possible; meanwhile, an adequate image quality sufficient for making diagnosis should be maintained. Moreover, the adverse reactions caused by contrast material (CM) also possess some concerns to patients� health . Among these concerns, acute renal failure is one of the notorious complications of procedures involving application of iodinated contrast media. For example, the contrast medium-induced nephropathy may account for about 12% of all cases of the nosocomial renal failure . Therefore, prevention of such a nephropathy is crucial as it is associated with an increased mortality rate . Since the adverse reactions are associated with the effectively consumed iodine amount, a small amount of CM should be used in scanning protocol to minimize the impairment of patients,