TABLE 2

Clinical Protocol Parameters for Each System

	System 1		System 2		System 3		System 4		System 5
Parameter	General	Brain	General	Brain	General	Brain	General	Brain	General	Brain
Number of projections	128	64	120	120	128	64	128	64	128	64
Matrix	128 × 128	64 × 64	64 × 64	128 × 128	128 × 128	64 × 64	128 × 128	128 × 128	128 × 128	64 × 64
Rotation	CO/NCO	CO/NCO	CO	CO	CO/NCO	CO/NCO	CO/NCO	CO/NCO	CO	CO
Counts per projection (kilocounts)	65	65	65	65	60	60	65	65	65	65
Zoom	1	1–1.46	1	1–1.28	1–1.23	1–1.45	1	1	1	1–1.46
Projection matrix	128 × 128	64 × 64	64 × 64	128 × 128	128 × 128	64 × 64	128 × 128	128 × 128	128 × 128	64 × 64
Filter	Butterworth	Hanning	Butterworth	Hanning	Butterworth	Butterworth	Butterworth	Butterworth	Hanning	Hanning
Cutoff frequency (cycle/mm)	0.064	0.055	0.064	0.055	0.031	0.031	0.085	0.085	0.070	0.070
Order	10		10		10	10	10	10
Attenuation coefficient (cm⁻¹)	0.12	0.12	0.12	0.12	0.15	0.15	0.16	0.16	0.12	0.12
Planar FWHM (mm)	15.12	15.12	13.41	13.41	13.74	13.74	13.11	13.11	23.53	23.53
Tomographic FWHM (mm)	15.25	15.25	13.68	13.68	14.21	14.21	13.47	13.47	26.11*	26.11*