TABLE 1

Periphery-to-Total Activity Ratio (Eq. 10) of Point Source

Kernel size (offset axially)	2 weighted exponentials				Single exponential
	3 × 3 × 3	5 × 5 × 5	9 × 9 × 9	15 × 15 × 15	15 × 15 × 15
1 cm	0.79	0.29	0.08	0.01	0.04
5 cm	0.78	0.28	0.08	0.01	0.04
10 cm	0.91	0.32	0.09	0.02	0.04