120 kV

100 kV

100 kV i

SD (HU)

Skull base

4.12 ± 0.36

4.22 ± 0.31

4.04 ± 0.33

Basal ganglia

3.99 ± 0.34

4.17 ± 0.31

4.00 ± 0.24

Vertex

3.99 ± 0.35

4.25 ± 0.37

4.08 ± 0.36

Average

4.02 ± 0.27

4.22 ± 0.23

4.04 ± 0.24

CT value (HU)

Gray matter

37.24 ± 2.59

40.79 ± 1.07

40.80 ± 1.12

White matter

30.16 ± 2.36

32.13 ± 1.11

32.11 ± 0.97

Contrast of them

7.08 ± 0.56

8.66 ± 0.73

8.68 ± 0.61

CNR

1.77 ± 0.13

2.06 ± 0.15

2.15 ± 0.15

Output dose (estimated patient exposure dose)

CTDIvol (mGy)

84.23 ± 3.87

85.90 ± 1.46

58.78 ± 4.33

DLP (mGy∙mm)

1412 ± 109.1

1481 ± 143.1

1027 ± 92.7

Effective dose (mSv)

2.97 ± 0.23

3.09 ± 0.30

2.16 ± 0.19