TABLE 1

Volumes and Locations of the 17 Spheres in the Phantom

Sphere	Location	Volume (mL)
1	Lung insert	0.4
2	Background	0.6
3	Background	1.0
4	Background	1.2
5	Background	1.6
6	Liver insert	2.1
7	Background	2.7
8	Lung insert	3.8
9	Background	5.6
10	Background	11.6
11	Background	11.7
12	Background	13.6
13	Lung insert	19.3
14	Background	26.6
15	Background	27.9
16	Lung insert	58.1
17	Liver insert	97.3