Table 4.
Striatal DAT availabilities, declines per decade of DAT availabilities, and striatum sizes in the regions: (1) inside both the threshold ROIs and the atlas-defined ROIs, (2) inside the threshold ROIs but outside the atlas-defined ROIs, and (3) outside the threshold ROIs but inside the atlas-defined ROIs.
| Thresholds | Inside threshold, inside atlas | Inside threshold, outside atlas | Outside threshold, inside atlas | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Average∗∗∗∗ | Decline∗∗∗ | Size∗∗ | Average∗∗∗∗ | Decline∗∗∗ | Size∗∗ | Average∗∗∗∗ | Decline∗∗∗ | Size∗∗ | |
| 90% | 2.71, 2.68∗ | 5.04%, 5.93% | 33.8, 41.1 | 2.65, 2.62 | 6.00%, 6.10% | 15.8, 8.5 | 1.28, 1.40 | 9.43%, 7.59% | 646.8, 596.2 |
| 85% | 2.55, 2.56 | 6.13%, 6.06% | 69.4, 82.2 | 2.50, 2.48 | 6.11%, 6.23% | 42.0, 29.1 | 1.22, 1.33 | 9.54%, 7.97% | 611.3, 555.1 |
| 80% | 2.43, 2.43 | 6.28%, 6.08% | 113.4, 130.8 | 2.36, 2.33 | 6.17%, 6.43% | 84.6, 67.2 | 1.14, 1.24 | 9.77%, 8.28% | 567.2, 506.6 |
| 75% | 2.31, 2.32 | 6.40%, 6.17% | 162.2, 184.1 | 2.21, 2.19 | 6.27%, 6.47% | 150.4, 128.5 | 1.06, 1.15 | 10.03%, 8.75% | 518.4, 453.3 |
| 70% | 2.19, 2.20 | 6.54%, 6.21% | 215.9, 242.0 | 2.07, 2.04 | 6.46%, 6.68% | 246.6, 220.5 | 0.96, 1.05 | 10.51%, 9.30% | 464.7, 395.4 |
| 65% | 2.08, 2.10 | 6.68%, 6.25% | 270.0, 298.8 | 1.92, 1.89 | 6.64%, 6.84% | 377.0, 348.2 | 0.87, 0.95 | 11.02%, 9.99% | 410.6, 338.5 |
| 60% | 1.97, 2.00 | 6.82%, 6.29% | 325.4, 354.7 | 1.77, 1.75 | 6.90%, 7.07% | 550.6, 521.3 | 0.78, 0.85 | 11.70%, 10.79% | 355.2, 282.6 |
*In each pair of data, the left is for MRI-normalization, while the right is for SPECT-normalization.
**Size: each voxel is of 2.897 mm × 2.897 mm × 2.897 mm.
***Decline per decade.
****For comparisons, the same OC averages from the threshold-ROI methods were used in the calculation of (ST-OC)/OC.