Table 1.

Uniformity evaluation in axial, radial and tangential profiles. The directions and their plots can be seen in Figure 2. Average, maximum and minimum indicate average activity concentration and the maximum and minimum values in the VOI, respectively. The percentage standard deviation (%STD) is a radio of standard deviation of activity concentration to average activity in the VOI.

	Scan method	Single	Multiple
Direction			Room1	Room2	Room3	Room4
Axial	Average	1.01	0.982	1.00	1.04	1.06
	Maximum	1.03	1.06	1.07	1.12	1.15
	Minimum	0.976	0.928	0.955	0.962	0.993
	%STD	0.955	1.89	1.98	2.09	2.02
	Flatness %	105	114	112	116	115
Radial	Average	1.01	0.984	1.01	1.04	1.06
	Maximum	1.02	1.02	1.04	1.07	1.11
	Minimum	0.955	0.900	0.910	0.959	0.933
	%STD	1.60	2.57	2.90	2.82	3.63
	Flatness %	107	114	114	112	119
Tangential	Average	1.01	0.986	1.01	1.05	1.07
	Maximum	1.03	1.03	1.04	1.11	1.12
	Minimum	0.961	0.946	0.951	0.961	1.01
	%STD	1.55	1.88	2.12	3.00	2.67
	Flatness %	107	109	109	115	111