Compared with group A , the iDose algorithm in group B yielded a higher contrast-to-noise ratio ( CNR ; 48.1 10.1 , p < 0.05 ) , a higher signal-to-noise ratio ( SNR ; 13.8 5.4 , p < 0.05 ) , and a lower standard deviation ( SD ; 30.3 6.9 , p < 0.05 ) .