Objective: The objective of this study was to analyze radiation dose reduction and image quality by combining automated kV selection, tube current reduction, and iterative reconstruction.
Methods: This was a retrospective analysis of the excretory phase of 55 patients with 2 computed tomography urography examinations: automated kV selection with tube current reduction ("low-dose protocol": with filtered back projection vs iterative reconstruction) and routine dose examinations. Image quality was analyzed blindly and in side-by-side analyses, in addition to quantitative measurements.
Results: Low-dose protocol median dose change was -40% (-10.7 to +12.9 mGy); 100 kV was autoselected in 44 (80%) of 55 patients (body mass index range, 19-36 kg/m) with mean dose reduction of 42.5%. Whereas up to 19% of low-dose images with filtered back projection were inferior by blinded review (P < 0.001), low-dose iterative reconstruction images were not rated inferior (P = 1.0).
Conclusions: The combination of iterative reconstruction, automated kV selection, and tube current reduction results in radiation dose reduction with preserved image quality and diagnostic confidence.