Fig. 3.

Low dose chest CT in 62-year-old woman (BMI, 27 kg/m²) with postoperative lung cancer.

Transverse CT images at 5 mm thickness with full radiation dose reconstructed with (A) FBP and (B) IRIS, and (C) with half radiation dose reconstructed with IRIS. When two readers compared F-FBP (A) and F-IRIS (B) images as reconstruction effect, readers' preference scores of 4 and 4 for lung 5 mm images, 3 and 2 for mediastinum, 5 and 4 for lung 1 mm images, and 4 and 4 for overall (not shown). When they compared F-FBP (A) and H-IRIS (C) as reconstruction effect and radiation dose effect, two readers had preference scores of 4 and 4 each for lung 5 mm images, 2 and 3 for mediastinum, 5 and 4 for lung 1 mm images, and 4 and 4 overall (not shown). BMI = body mass index, F-FBP = full dose image with filtered back projection, F-IRIS = full dose image with iterative reconstruction in image space, H-IRIS = half dose image with iterative reconstruction in image space