Table 2.

Comparison of the regression lines between quantification methods of measuring DAT availabilities.

Method	Slope (P value∗)	Intercept	Decline per decade (95% CI∗∗)	R 2
(1) MRI-delineation	−0.015 (5.4 × 10−6)	2.49	6.66% (4.34–8.52%)	0.22
(2) SPECT-delineation	−0.013 (1.7 × 10−5)	1.62	9.47% (5.99–14.13%)	0.20
(3) Template-ROI	−0.011 (1.3 × 10−5)	1.86	6.81% (4.52–8.77%)	0.25
(4) 90% Threshold-ROI	−0.018 (1.7 × 10−4)	3.31	5.95% (3.34–8.10%)	0.16
(5) 85% Threshold-ROI	−0.017 (1.5 × 10−4)	3.15	6.09% (3.46–8.29%)	0.16
(6) 80% Threshold-ROI	−0.017 (1.4 × 10−4)	2.99	6.19% (3.63–8.45%)	0.16
(7) 75% Threshold-ROI	−0.016 (1.3 × 10−4)	2.84	6.29% (3.60–8.63%)	0.16
(8) 70% Threshold-ROI	−0.015 (1.0 × 10−4)	2.68	6.47% (3.45–8.73%)	0.17
(9) 65% Threshold-ROI	−0.015 (8.7 × 10−5)	2.52	6.64% (3.62–9.10%)	0.17
(10) 60% Threshold-ROI	−0.014 (7.9 × 10−5)	2.36	6.88% (3.86–9.42%)	0.17
(11) MRI-normalization	−0.018 (5.1 × 10−8)	1.95	11.02% (7.98–13.66%)	0.31
(12) MRI-normalization with VC	−0.021 (5.5 × 10−8)	2.24	11.17% (8.12–13.80%)	0.30
(13) MRI-normalization with GTM	−0.028 (1.7 × 10−7)	2.89	11.85% (8.45–14.77%)	0.29
(14) MRI-normalization with RBV	−0.027 (3.8 × 10−7)	2.80	11.99% (8.45–15.03%)	0.27
(15) SPECT-normalization	−0.014 (3.3 × 10−9)	2.01	8.30% (6.15–9.90%)	0.35
(16) SPECT-normalization with VC	−0.017 (4.5 × 10−9)	2.35	8.28% (6.18–9.93%)	0.34
(17) SPECT-normalization with GTM	−0.021 (1.2 × 10−8)	3.01	7.99% (5.84–9.63%)	0.33
(18) SPECT-normalization with RBV	−0.020 (2.0 × 10−8)	2.91	8.04% (5.87–9.71%)	0.32

CI, confidence interval; DAT, dopamine transporter; MRI, magnetic resonance imaging; SPECT, single photon emission-computed tomography; ROI, region of interest; GTM, geometric transfer matrix; RBV, region-based voxel-wise; VC, Van-Cittert deconvolution.

*P-values for H ₀: β ₁ = 0.

**95% Confidence intervals for declines per decade using 10,000 bootstrap samples.