Evolution of Coronary Computed Tomography Radiation Dose Reduction at a Tertiary Referral Center

PurposeWe aimed to assess the temporal change in radiation doses from coronary computed tomography angiography (CCTA) during a 6-year period. High CCTA radiation doses have been reduced by multiple technologies that, if used appropriately, can decrease exposures significantly.MethodsA total of 1277 examinations performed from 2005 to 2010 were included. Univariate and multivariable regression analysis of patient- and scan-related variables was performed with estimated radiation dose as the main outcome measure.ResultsMedian doses decreased by 74.8% (P < .001), from 13.1 millisieverts (mSv) (interquartile range 9.3-14.7) in period 1 to 3.3 mSv (1.8-6.7) in period 4. Factors associated with greatest dose reductions (P < .001) were all most frequently applied in period 4: axial-sequential acquisition (univariate: −8.0 mSv [−9.7 to −7.9]), high-pitch helical acquisition (univariate: −8.8 mSv [−9.3 to −7.9]), reduced tube voltage (100 vs 120 kV) (univariate: −6.4 mSv [−7.4 to −5.4]), and use of automatic exposure control (univariate: −5.3 mSv [−6.2 to −4.4]).ConclusionsCCTA radiation doses were reduced 74.8% through increasing use of dose-saving measures and evolving scanner technology.