TABLE 4.

Semiquantification of ^99mTc-ECD Perfusion Studies for 10 Healthy Volunteers with Nonuniform Versus Uniform Transmission Correction

Region	VOI size*	NUAC† (¹⁵³Gd)	UAC‡	Difference	P§ (t test)
Cortical
Frontal	3000	97.1 ± 1.7	97.7 ± 3.6	−0.6	(0.53)
Sensorimotor cortex	514	98.6 ± 4.6	98.7 ± 5.0	−0.1	(0.94)
Temporal	1185	93.2 ± 2.7	92.7 ± 2.4	0.6	(0.49)
Parietal	850	99.5 ± 3.3	100.3 ± 3.4	−0.9	(0.26)
Occipital	1167	100.9 ± 2.2	99.8 ± 6.2	1.1	(0.54)
Total	6716	97.5 ± 1.6	97.6 ± 1.6	−0.1	(0.78)
Subcortical
Mediotemporal	343	70.7 ± 3.8	74.3 ± 3.8	−3.7	0.006
Basal ganglia	357	111.0 ± 4.9	117.4 ± 4.7	−6.4	0.001
Total	700	91.1 ± 3.6	96.2 ± 3.0	−5.1	0.000
Central
Thalamus	232	94.3 ± 4.8	100.9 ± 4.6	−6.7	0.000
Pons	130	82.9 ± 4.9	84.2 ± 6.0	−1.3	(0.29)
Total	362	90.2 ± 3.0	94.9 ± 3.1	−4.8	0.000
Cerebellum	1596	116.7 ± 5.1	113.0 ± 6.1	3.7	0.023

↵* In voxels of 3.59 × 3.59 × 3.59 mm³.
↵† NUAC with ¹⁵³Gd and iterative Chang (one iteration); semiquantitative values are given in % ± SD with normalization to total VOI counts.
↵‡ Uniform Sorenson attenuation correction ± SD with μ_eff = 0.105 per cm.
↵§ Values in parentheses are not significant.