Table 2.

Cumulative tube current values for the chest scan and information whether the scan was done with or without out-of-plane shield in localizer images (but outside the scanned volume). The difference between these two values, their relative difference, and location of the > 20% tube current increase along the z-axis (starting point of the scan is valued as 0 cm and the end of the scan 32 cm)

	Pitch	Cumulative tube current, no shield (mA)	Cumulative tube current, with shield (mA)	Difference (shield-no shield) (mA)	Relative difference (%)	z-location of the > 20% tube current difference (cm)
GE Optima	0.516	5065	8808	3743	74	29.1
	0.984	11,302	24,004	12,702	112	27.3
	1.375	15,393	26,279	10,886	71	27.9
	1.531	15,818	50,218	34,400	217	23.1
GE Revolution	0.508	14,336	19,662	5326	37.2	26.9
	0.992	37,290	53,168	15,878	42.6	26.3
	1.375	53,312	71,015	17,703	33.2	25.5
	1.531	55,147	78,889	23,742	43.1	24.2
Canon One	0.637	63,954	66,499	2545	3.98	29.9
	0.813	69,547	76,739	7192	10.3	29.0
	1.388	121,837	143,648	21,811	17.9	27.1
Canon Prime	0.637	56,247	66,242	9995	17.8	29.5
	0.813	63,607	76,941	13,334	21.0	28.6
	1.388	109,280	167,543	58,263	53.3	22.3
Canon Prime SP	0.637	181,542	187,897	6355	3.50	30.6
	0.813	206,421	214,552	8131	3.94	30.9
	1.388	321,365	322,690	1325	0.41	-
Siemens Go.Up	0.35	14,934	15,065	131	0.88	-
	0.65	24,020	24,063	43	0.18	-
	0.95	36,181	36,230	49	0.14	-
	1.2	45,283	45,275	− 8	− 0.02	-
	1.5	57,605	57,402	− 203	− 0.35	31.7