Table 1 Protocols of non-gated chest CT and ECG-gated CT

N

202

98

105

405

Rot.(s)

0.5

0.5

0.5

0.25

Exposure Time/Rot.(s)

0.5

0.5

0.5

0.15

Pitch

0.95

1.2

0.83

NA

Collimator (mm)

1.2 × 24

0.6 × 64

0.5 × 32

1.2 × 40

Inplane resolution (mm)

0.77 × 0.77

0.73 × 0.73

0.78 × 0.78

0.33 × 0.33

Convolution Kernel

B30f, B35f

B30f, B35f

FC18

Qr36f

DLP(mGy*cm)^a

186 (164–243)

284 (213–347)

338 (251–416)

35 (28–33)

EDvol(mSv)^b

2.6 (2.3–3.4)

4.0 (3–4.9)

4.7 (3.5–5.8)

0.5 (0.4–0.5)

Slice thickness (mm)

1.5

1.5, 2.0

2.0

3.0

Increment (mm)

1.2

1.2,1.5

1.5

1.5