Table 1.

Scan protocols for all phantom scans using the Philips Brilliance and the HD750 GE Discovery CT scanners. All protocols are helical scans.

Phantom	Protocol	Pitch	mA	Tube rotation time (s)	Filter	SFOV (cm)	Slice thickness (cm)	DFOV (cm)	Recon kernel	CTDIvol (mGy)
RMI phantom	Philips 120kVp	0.938	375	0.75	B	60	3	36	B	19.9
	GE 120kVp	0.969	450	0.5	Medium	50	2.5	36	Standard	21.2
	GE GSI preset #35	0.969	630	0.5	Medium	50	2.5	36	Standard	20.2
Head phantom	Philips 120kVp	0.688	202	0.75	B	60	3	25	B	26.2
	GE 120kVp	0.516	280	0.6	Medium	50	2.5	25	Standard	26.0
	GE GSI preset #32	0.516	375	0.6	Medium	50	2.5	25	Standard	26.0
Pelvic phantom	Philips 120kVp	0.938	263	0.75	B	60	3.0	36	B	13.9
	GE 120kVp	0.984	265	0.6	Medium	50	2.5	36	Standard	12.7
	GE GSI preset #41	0.984	360	0.6	Medium	50	2.5	36	Standard	12.8
Spine phantom	Philips 120kVp	0.938	300	0.75	B	60	3.0	50	B	15.9
	GE 120kVp	0.969	265	0.7	Medium	50	2.5	50	Standard	17.1
	GE GSI preset #25	0.969	375	0.7	Medium	50	2.5	50	Standard	17.0