Stereotactical normalization with multiple templates representative of normal and Parkinson-typical reduction of striatal uptake improves the discriminative power of automatic semi-quantitative analysis in dopamine transporter SPECT

EJNMMI Physics

Table 2 Fit of the histogram of the putamen SBR by the sum of two Gaussian functions

Single/multiple templates	Reduced		Normal		Effect size	Cutoff
Single/multiple templates	M₁	SD₁	M₂	SD₂	d	c
HV_min	0.63/0.58	0.18/0.15	1.72/1.57	0.36/0.32	3.83 ± 0.05/3.96 ± 0.05	0.995/0.904
HV_mean	0.71/0.67	0.20/0.18	1.77/1.63	0.37/0.32	3.56 ± 0.05/3.74 ± 0.05	1.086/1.013
HV_left	0.73/0.67	0.22/0.19	1.78/1.63	0.37/0.33	3.42 ± 0.05/3.55 ± 0.05	1.116/1.013
HV_right	0.66/0.61	0.20/0.17	1.73/1.58	0.39/0.36	3.46 ± 0.06/3.48 ± 0.05	1.019/0.928
AAL_min	0.83/0.75	0.30/0.28	2.11/2.00	0.43/0.41	3.47 ± 0.04/3.53 ± 0.04	1.360/1.253
AAL_mean	0.99/0.91	0.31/0.28	2.20/2.10	0.42/0.41	3.25 ± 0.04/3.39 ± 0.04	1.501/1.402
AAL_left	1.07/1.00	0.35/0.34	2.25/2.21	0.43/0.41	3.01 ± 0.04/3.23 ± 0.03	1.600/1.547
AAL_right	0.84/0.75	0.30/0.28	2.10/1.97	0.46/0.45	3.25 ± 0.04/3.25 ± 0.04	1.338/1.215

Mean values M₁, M₂ and standard deviations SD₁, SD₂ from the fit of the histogram of the putamen SBR by the sum of two Gaussian functions according to Eq. (1) in the whole sample, effect size d of the distance between the two Gaussian functions according to Eq. (2) (mean ± standard deviation from 1000 random 90% subsamples), and cutoff c for the dichotomization of SBR as normal or reduced according to Eq. (3) in the whole sample. The results are given separately for HV analysis and conventional semi-quantitative analysis with the anatomical AAL putamen masks, and for minimum (min) and mean SBR of both hemispheres and for left and right SBR. The results for stereotactical normalization with the single template or with multiples templates are given in each cell (single/multiple templates)