Table 2.

The sampling parameters of the Focus-120 animal PET scanner’s system matrices used for image reconstruction reported in this work. Note that the LOR lengths between different detector blocks vary. The specific descriptions of the γγ, ¹⁸F and ¹⁵O sources are described in section 2.5. The size of the final system matrix is 64×64×19×5×21×9 or ~ 74 million elements. To facilitate visual presentation, a different set of parameters was used for the LOR-PDFs shown in Figures 5-8.

Variable	Range	Number of samples	Sample size
r	[−5,5]mm for γγ ,18F; [−10,10]mm for 15O	64	~0.16mm for γγ,18F; ~0.32mm for 15O
u	[−5,5] mm for γγ, 18F; [−10,10]mm for 15O	64	~0.16mm for γγ, 18F; ~0.32mm for 15O
d	[0, Lb] mm, Lb ≈ 40.7 to 157.2	19	~2.1 to 8.3 mm
φ	[φb-7.5°, φb+7.5°	5	3°
b	[2, 22]	21	1 block index
θ	[−49.5°,49.5°]	9	11°