Fig. 2
Effect of using dose-tracking systems on differences in CTDIvol levels between scanners within one hospital. a Graph showing the median CTDIvol and interquartile range per month (period January 2013–June 2013) of CT-head examinations for the two CT systems in hospital A with the national P75 DRL as benchmark. b Box plot of the CTDIvol-median value, interquartile range, total range and outliers for all CT-abdomen-pelvis examinations on the five CT systems with the national P75 and P25 DRLs as benchmark, demonstrating median CTDIvol levels between both CT systems in hospital A and between both CT systems in hospital C are not different. c Box plot of the CTDIvol-median value, interquartile range, total range and outliers for all CT-thorax-abdomen examinations on three CT systems with the national P75 and P25 DRLs as benchmark, demonstrating median CTDIvol levels between both CT systems in hospital A and between both CT systems in hospital C are not different. Kruskal-Wallis test with post-hoc Dunn test. Adjusted p values not shown on the graph are below 0.01