Compared with two Iopromide 370 subgroups , Iomeprol 270 subgroups showed no significant difference in CT attenuation ( 576.63 95.50 vs. 569.51 118.93 for BMI < 25 kg/m ( 2 ) , p = 0.647 and 394.19 68.09 vs. 383.72 63.11 for BMI 25 kg/m ( 2 ) , p = 0.212 ) , noise ( in various anatomical regions of interest ) and image quality ( 3.5 vs. 4.0 , p = 0.13 ) , but significantly ( 0.41 0.17 vs. 0.94 0.45 for BMI < 25 kg/m ( 2 ) , p < 0.001 and 1.14 0.24 vs. 2.37 0.69 for BMI 25 kg/m ( 2 ) , p < 0.001 ) lower radiation dose , which reflects dose saving of 56.4 % and 51.9 % , respectively .