Table 4 Comparison of quantitative image analysis data of the ASIR and non-ASIR groups

Tube current (mA)/reconstruction

148 mA/non-ASIR

Tube current (mA)/ASIR reconstruction

SNR

SNR

CNR

CNR

ASIR 60%

ASIR 80%

ASIR 60%

ASIR 80%

ASIR (n = 27)

6.43 ± 1.01

7.37 ± 0.75

1.54 ± 0.37

1.63 ± 0.27

Test of significance with non-ASIR group

t = 2.37, p = 0.07

t = 0.176, p = 0.96

t = 2.11, p = 0.9

t = 2.43, p = 0.687

40 mA/ASIR (n = 7)

4.9 ± 1.13

5.67 ± 1.11

1.28 ± 0.28

1.48 ± 0.31

Test of significance with non-ASIR group

t = 5.94, p = 0.001*

t = 4.18, p = 0.005*

t = 3.99, p = 0.0008*

t = 2.62, p = 0.016*

60 mA/ASIR (n = 8)

6.37 ± 0.78

7.39 ± 0.53

1.56 ± 0.47

1.85 ± 0.28

Test of significance with non-ASIR group

t = 3.02, p = 0.06

t = 0.155, p = 0.877

t = 1.88, p = 0.075

t = 0.276, p = 0.786

80 mA/ASIR (n = 7)

6.79 ± 1.24

7.56 ± 0.74

1.42 ± 0.46

1.64 ± 0.08

Test of significance with non-ASIR group

t = 1.45, p = 0.163

t = 0.329, p = 0.746

t = 2.62, p = 0.017*

t = 2.17, p = 0.08

100 mA/ASIR (n = 5)

7.66 ± 0.88

8.88 ± 0.517

1.88 ± 0.24

2.17 ± 0.36

Test of significance with non-ASIR group:

t = 0.51, p = 0.616

t = 3.67, p = 0.0019*

t = 0.06, p = 0.95

t = 1.53, p = 0.146