As shown in Table 1, when the tube current was decreased from 240 to 60 mA for scan series without AIDR3D, lower tube currents resulted in higher LAA% values and lower 15th percentiles. The differences in measures between 240 and 120 mA, between 120 and 60 mA, and between 240 and 60 mA were judged to be significant (LAA%, P,0.0001; 15th percentile, P,0.01). However, on scans with AIDR3D, the differences in measures of LAA% and 15th percentile among the three tube current settings were not significant, although very slight increases in LAA% and decreases in 15th percentiles were observed by changing the tube current from 240 to 60 mA.