Figure 3

The adrenal nodule in each CT image. An adrenal nodule with 20 mm in longest diameter (white arrow) in axial unenhanced CT images of UL-MBIR (a), L-ASIR (b), UL-ASIR (c) and R-FBP (d) of a 65-year-old man weighing 61 kg. In UL-ASIR (c), the margin of this adrenal nodule is obscure due to the prominent image noise. The certainty level (UL-MBIR/L-ASIR/UL-ASIR) for this lesion by each reader was 4 (lesion definitely present)/3(lesion probably present)/3 by reader 1 and 3/3/0(no lesion) by reader 2, respectively.