. 2012 Jul 13;39(9):1497–1509. doi: 10.1007/s00259-012-2177-x

Table 2.

Impact of radial offset on spatial resolution and of axial offset on sensitivity of commercially available scanners

Scanner	Reference	Reconstruction algorithm	FWHM (mm)^a									Sensitivity (%)^a
			Centre of FOV			2 cm radial offset			3 cm radial offset			Centre of FOV	2 cm axial offset	3 cm axial offset
			Tangential	Radial	Axial	Tangential	Radial	Axial	Tangential	Radial	Axial	Centre of FOV	2 cm axial offset	3 cm axial offset
Triumph LabPET-8	[38]	FBP^a	1.8	1.7	2.4	1.7	2.3	2.5	1.7	2.7	2.7	1.3	0.9	0.5
Triumph LabPET-8	[38]	MLEM^b	1.0	0.8	1.6	1.2	1.1	1.5	1.3	1.2	1.5
Inveon	[26, 30]	FBP^a	1.5	1.6	2.0	1.5	2.1	2.4	1.6	2.1	2.4	10.1	6.9	5.3
Inveon	[26, 30]	OSEM/MAP^c	1.6	1.6	1.7	1.6	1.7	1.6	1.7	1.8	1.6
NanoPET/CT	[27]	FBP^a	1.15	1.38	1.47	1.64	2.04	1.6	1.81	2.54	1.89	7.7	4.8	3.1
NanoPET/CT	[27]	3-D OSEM^d	0.59	0.72	0.60	0.71	0.90	0.66	0.78	1.06	0.65

FBP filtered back-projection, MLEM maximum likelihood expectation maximization, OSEM ordered subsets expectation maximization, MAP maximum a posteriori.

Data for the Triumph LabPET-8 and the Inveon systems were interpolated from Prasad et al. [38] and Visser et al. [30], respectively, and data for the NanoPET/CT system were calculated for the purposes of this paper.

^aData obtained as per NEMA protocol.

^bTen iterations.

^c18 iterations/16 subsets, uniformity constraint set to “resolution”, smoothing parameter β = 0.5; all MAP reconstructions were preceded by two 3-D OSEM iterations.

^d20 iterations/1 subset, no postfiltering.