Table 7.

CT dose and induced σN_CT for a range of imaging protocols (Baxter et al 2007).

Imaging protocol	Phantom	kVp	mAs	Slice (mm)	Dose/image (cGy)	No of image averages	ΔNCT
Volumetric	16 cm diam.	120	200	2	3.38 ± 0.14	16	0.105 ± 0.001
(CTDI)	(center)			5	3.4 ± 0.1	16	0.105 ± 0.001
				10	3.4 ± 0.1	16	0.107 ± 0.001
	16 cm diam.	140	200	2	3.5 ± 0.1	16	0.109 ± 0.001
	(edge)			5	3.5 ± 0.1	16	0.110 ± 0.001
				10	3.6 ± 0.1	16	0.111 ± 0.001
	16 cm diam.	140	200	2	4.4 ± 0.2	16	0.136 ± 0.002
	(center)			5	4.4 ± 0.2	16	0.136 ± 0.002
				10	4.5 ± 0.2	16	0.138 ± 0.002
	16 cm diam.	140	200	2	4.5 ± 0.2	16	0.139 ± 0.002
	(edge)			5	4.5 ± 0.2	16	0.139 ± 0.002
				10	4.6 ± 0.2	16	0.141 ± 0.002
Single slice	16 cm diam.	120	200	2	0.70 ± 0.05	32	0.0430 ± 0.0002
(PD)	(center)			5	0.91 ± 0.06	32	0.0560 ± 0.0004
				10	1.07 ± 0.07	32	0.066 ± 0.001
	16 cm diam.	120	200	2	1.6 ± 0.1	32	0.099 ± 0.001
	(edge)			5	1.7 ± 0.1	32	0.107 ± 0.001
				10	2.1 ± 0.2	32	0.133 ± 0.002
	16 cm diam.	140	200	2	0.83 ± 0.06	32	0.0510 ± 0.0003
	(center)			5	1.07 ± 0.07	32	0.066 ± 0.001
				10	1.23 ± 0.09	32	0.076 ± 0.001
	16 cm diam.	140	200	2	1.5 ± 0.1	32	0.095 ± 0.001
	(edge)			5	2.0 ± 0.1	32	0.125 ± 0.002
				10	2.1 ± 0.2	32	0.130 ± 0.002
Calibration	Calibration	140		10	2.3 ± 0.2	16	0.0720 ± 0.0001
(PD)	gel vials