TABLE I. Imaging Protocols of the CT Exams.

	No. slices	Slice thickness (mm)	Matrix size	Pixel spacing (mm)	KVP (kV)	Collimation (mm)	Pitch
COVID-19	38–629	0.625–7.5	512×512	0.604–0.977	100–130	(4–128)×(0.6–3.75)	0.75–1.5
CAP	24–1,309	0.5–7	512×512	0.482–0.951	110–140	(8–128)×(0.6–1.25)	0.734–1.438
Non-pneumonia	24–879	0.75–10	512×512	0.5–0.977	100–140	(4–128)×(0.6–2.5)	0.75–1.5

The CT volumes are not of a uniform size, which makes the No. slices vary in a range.

Isotropic pixel sizes.

Automatic tube current was used.