Table 1. The acquisition and reconstruction parameters of LDCT.

Parameters	Primary cohort	Validation cohort
Scanner	Brilliance iCT	Somatom Definition Flash
Tube voltage	100 kV	100 kV
Tube current	20 or 30 mAs	10 or 20 or 30 mAs
Pitch	0.915	1
Collimation	128×0.625 mm	128×0.6 mm
Rotation time	0.4 s	0.33 s
Field of view	350 mm × 350 mm	350 mm × 350 mm
Reconstruction
Algorithm	Iterative reconstruction (iDose4, level 6)	Iterative reconstruction (SAFIRE, Strength level 5)
Slice thickness	0.625 mm	0.5 mm
Slice increment	0.625 mm	0.5 mm
Matrix	512×512	512×512

LDCT, low-dose computed tomography.