Table 2.

Contrast recovery and background variability parameters when applying CT-based AC

Sphere size [mm]	Radioactive / Non-radioactive	aContrast recovery [%]	aBackground variability [%]
10	Radioactive	30.5 ± 1.3	3.8 ± 0.8
13	Radioactive	50.5 ± 2.4	3.0 ± 0.5
17	Radioactive	72.9 ± 1.9	2.5 ± 0.2
22	Radioactive	74.5 ± 3.3	2.3 ± 0.2
28	Non-radioactive	56.6 ± 2.3	2.0 ± 0.2
37	Non-radioactive	64.8 ± 0.9	1.8 ± 0.1

^a The values represent the mean values and standard deviation of four independent measurements for the reconstruction: 3 iterations, 21 subsets, 172 matrix and 4 mm Gaussian filtering