Automatic vs. Manual Outlining of Reference Region
| Patient no. | Mean activity | Absolute value of activity difference(%) | No. of pixels | ||
|---|---|---|---|---|---|
| Automatic | Manual | Automatic | Manual | ||
| 1 | 3,248.52 | 3,163.99 | 2.60 | 684 | 204 |
| 2 | 3,363.34 | 3,459.09 | 2.85 | 858 | 614 |
| 3 | 1,961.70 | 2,140.11 | 9.09 | 905 | 778 |
| 4 | 4,203.95 | 4,062.69 | 3.36 | 827 | 703 |
Difference in patient 3 is largest because manually defined ROI covered blood vessels (Fig. 9)