TABLE 1

Quantitative Measures of Reference Sphere in Healthy Liver Tissue Using TOF OSEM and BSREM

		BSREM
Measure	TOF OSEM^*	β-factor, 133	β-factor, 267	β-factor, 400	β-factor, 533
Volume (cm³)	19.2 (18.0–19.6)
SUV_max	2.9 (2.1–4.0)	4.2 (2.7–5.4)	3.1 (2.2–4.0)	2.8 (2.0–3.7)	2.6 (2.0–3.5)
SUV_mean	2.1 (1.6–2.6)	2.0 (1.6–2.5)	2.0 (1.6–2.5)	2.1 (1.6–2.6)	2.1 (1.6–2.6)
SUV_SD	0.2 (0.2–0.4)	0.4 (0.3–0.6)	0.3 (0.2–0.4)	0.2 (0.2–0.3)	0.2 (0.1–0.3)
Noise level^*	0.11 (0.09–0.16)	0.22 (0.18–0.28)	0.13 (0.11–0.17)	0.10 (0.08–0.13)	0.09 (0.07–0.11)

↵* Measured in liver and defined as SUV_SD divided by SUV_mean.
Data are mean followed by range. TOF OSEM used 3 iterations, 16 subsets, 5-mm gaussian postprocessing filter, and PSF. BSREM included TOF and PSF with β-factors of 133, 267, 400, and 533; 70-cm FOV; and 3 min/bp.