TABLE 1

Parameters for 2 Phantom Experiments

Parameter	Units	Goal^†	Experiment 1*		Experiment 2
Parameter	Units	Goal^†	True^‡	Measured^§	True^‡	Measured^§
Lungs	kBq/mL	4.5	3.33	1.3	13.7	9.62
Heart chamber	kBq/mL	18	13.0	17.1	15.2	15.3
Heart wall	kBq/mL	52	30.7	24.0	66.6	49.2
Liver	kBq/mL	21	14.2	16.8	22.8	22.6
Phantom background	MBq		48.1		122
Head	MBq		81.4		100
Head position^{^∥}	cm		38.0		15.0
Bladder	MBq		955		1,200
Bladder position^∥	cm		33		15
True events	Megacounts	10		3		4.3
Random events	Megacounts	6		1.8		14.4

↵* Experiment was started 70 min late and so corresponds to 1070 MBq injected rather than 1480 MBq.
↵† Values determined from recorded counting rates or ROIs from 2D scanning (1480 MBq ⁸²Rb) of typical human subject.
↵‡ True radioactivity used to fill phantom inserts; decay corrected to first PET acquisition.
↵§ Radioactivity determined by drawing ROIs on first phantom PET images.
↵∥ Distance from end of thoracic phantom to center of 3-L cylinder used to simulate head and bladder radioactivity.
ROI = region of interest.