Table 1. CT Image Acquisition Parameters.

	Somatom Definition AS+, Siemens Healthineers	Discovery CT750 HD, GE Healthcare	Ingenuity Core 128, Philips Healthcare
Radiation dose*
STD	120 kVp and 220 reference mAs	120 kVp and 100–400 mA	120 kVp and 321 reference mAs
LD-kVp	80 kVp and 220 reference mAs	80 kVp and 100–400 mA	80 kVp and 321 reference mAs
LD-mAs	120 kVp and 100 reference mAs	120 kVp and 10–300 mA	120 kVp and 168 reference mAs
Slice thickness* (mm)
Thin section	1	1.25	1
Medium section	3	2.5	3
Thick section	5	5	5
Reconstruction algorithm*	FBP IR (SAFIRE, iterative strength level 1)	FBP IR (ASIR 30%)	FBP IR (iDose4)
Field of view (mm)	380
Kernel	Standard

^*A total of 18 images per device were obtained with the modulation of radiation dose (three conditions), slice thickness (three conditions), and reconstruction algorithm (two conditions). ASIR = adaptive statistical iterative reconstruction, FBP = filtered back projection, IR = iterative reconstruction, LD-kVp = low dose with reduced voltage, LD-mAs = low dose with reduced current, SAFIRE = sinogram affirmed iterative reconstruction, STD = standard dose