TABLE 4

PET/SPECT Sensitivity Ratios

			PET/SPECT sensitivity ratio (Eq. 5)
Area and measurement series	SPECT radionuclide	Collimator	Close detector (10-cm distance)	Distant detector (∼60-cm distance)	SPECT radionuclide sensitivity on close detector (cps/MBq)^*
Full detector
A	^99mTc	LEHR	31	7	82
B	^99mTc	MELP	2.3	0.8	115
C	^99mTc	HE	0.8	0.3	87
D	¹¹¹In	MELP	3.9	1.4	208
E	¹¹¹In	HE	1.7	0.8	108
Within SPECT ROI
A	^99mTc	LEHR	0.070	0.054	74
B	^99mTc	MELP	0.002	0.008	114
C	^99mTc	HE	0.001	0.002	82
D	¹¹¹In	MELP	0.005	0.017	166
E	¹¹¹In	HE	0.002	0.006	102
Same location^†
A	^99mTc	LEHR	0.48	0.07	(see SPECT ROI)
B	^99mTc	MELP	0.08	0.05	(see SPECT ROI)
C	^99mTc	HE	0.06	0.04	(see SPECT ROI)
D	¹¹¹In	MELP	0.16	0.08	(see SPECT ROI)
E	¹¹¹In	HE	0.14	0.10	(see SPECT ROI)