TABLE 1

Object-to-Background Ratio and SNR for Simulations with 0.4, 0.8, 1.6, and 3.2 Million Counts

Reconstruction method	Object-to-background ratio	SNR for total counts of
Reconstruction method	Object-to-background ratio			0.4	0.8	1.6	3.2
FBP att corr	4.98	71	102	147	209
FBP no corr	18.1	66	94	135	192
MLEM att corr	5.08	72	102	153	209
MLEM no corr	13.3	69	97	146	201
NEG-ML no corr	18.7	69	97	146	198

SNR = signal-to-noise ratio; att corr = with attenuation correction; no corr = without attenuation correction.