CT pulmonary angiogram with 60% dose reduction: Influence of iterative reconstructions on image quality

Abstract Goals To compare the quality of low-dose CT images with sinogram affirmed iterative reconstruction (SAFIRE), and full-dose CT with filtered back projection reconstructions (FBP). Materials and methods Fifty pulmonary CT performed by a dual-source technique (120 kVp; 110 mAs) with (a) the same energy in both tubes, and (b) the distribution of reference mAs with 40% in tube A (44 mAs) and 60% in tube B (66 mAs). Each acquisition allowed reconstruction of: (a) full-dose images (with both tubes) with FBP reconstructions (group 1); and (b) low-dose images (from tube A) reconstructed with SAFIRE (group 2). Results Group 2 images presented: (a) a significant objective reduction in noise measured in the trachea on mediastinal (16.04 ± 5.66 vs 17.66 ± 5.84) ( P = 0.0284) and pulmonary (29.77 ± 6.79 vs 37.96 ± 9.03) ( P < 0.0001) images; (b) a similar subjective perception of noise and overall image quality ( P = 1), which was considered to be excellent in 66% (33/50) of the cases, with no influence on the detection of elementary pulmonary lesions of infiltration (98.4%; 95% CI = [96.9%–99.9%]). Conclusion Despite a 60% reduction in radiation dose, the image quality with iterative reconstruction is objectively better and subjectively similar to full-dose FBP images.