Table 1.

Mean K_i Estimates of [¹⁸F]FDG Uptake in the Mouse Brain Using Different Input Functions^*

Input Function Method	Fasted									Normal (Non-fasted)
	RC = 0.5 (n = 11)			RC = 0.7 (n = 7)			RC = 1 (n = 7)			RC = 0.5 (n = 7)
	Mean Ki (×10−3) mL/min/g	% diff	r2	Mean Ki (× 10−3) mL/min/g	% diff	r2	Mean Ki (× 10−3) mL/min/g	% diff	r2	Mean Ki (× 10−3) mL/min/g	% diff	r2
Input function 1 (arterial blood)	18.3 ± 2.9			22.4 ± 3.9			22.4 ± 3.9			18.6 ± 2.5
Input function 2 (arterial blood + part of the blood- pool region of the left ventricle peak curve)	15.5 ± 2.2	15	0.89	20.3 ± 3.3	9	0.87	22.0 ± 3.4	2	0.94	16.2 ± 2.1	13	0.95
Normalized hybrid IDIF (blood-pool region of the left ventricle peak curve + tail of liver TAC normalized to the ≈ 60 min arterial blood sample)	15.5 ± 2.3	15	0.86	21.5 ± 3.6	4	0.84	24.8 ± 3.9	11	0.87	20.5 ± 3.6	10	0.94
Non-normalized hybrid IDIF (blood-pool region of the left ventricle peak curve + tail of the liver TAC)	12.7 ± 1.6	31	0.46	15.1 ± 2.1	33	0.64	18.0 ± 2.4	20	0.67	12.7 ± 1.7	31	0.82

%diff = percent difference between each input function and input function 1, ie, % diff = 100% × |input function 1 − input function (2 or hybrid IDIF)|/input function 1; IDIF = image-derived input function; r² = coefficient of determination between each input function (input function 2 or hybrid IDIF) and input function 1; RC = recovery coefficient; TAC = time-activity curve.

^*See Methods for a complete description of the different input functions.

The mean K_i estimates are displayed as mean ± SE.