Interobserver Variability in Landmark Identification: Comparison Between Algorithm-Based and Scanner-Based Registration for 5 Cases with CT and PET Images from Combined Scanner
| Anatomic region | Interobserver variability in landmark identification Mean (95% CI) (mm) Maximum (mm) | P value | |||
|---|---|---|---|---|---|
| Scanner (mechanical registration) | Algorithm (elastic registration) | ||||
| Group 1 | Overall | 6.6 (5.9, 7.2) | 6.6 (5.9, 7.2) | — | |
| 12.3 | 12.3 | ||||
| Thoracic | 7.2 (6.6, 7.9) | 7.2 (6.6, 7.9) | — | ||
| 12.3 | 12.3 | ||||
| Abdominal | 5.5 (4.5, 6.5) | 5.5 (4.5, 6.5) | — | ||
| 11.6 | 11.6 | ||||
| Group 2 | Overall | 7.0 (6.4, 7.7) | 6.0 (5.5, 6.6) | <0.05 | |
| 14.3 | 14.1 | ||||
| Thoracic | 8.1 (7.4, 8.8) | 6.8 (6.2, 7.4) | <0.05 | ||
| 14.3 | 11.9 | ||||
| Abdominal | 5.4 (4.4, 6.4) | 4.8 (3.9, 5.8) | NS | ||
| 12.9 | 14.1 | ||||
| Group 3 | Overall | 7.2 (6.6, 7.9) | 6.1 (5.5, 6.6) | <0.05 | |
| 12.9 | 12.3 | ||||
| Thoracic | 8.3 (7.5, 9.1) | 6.8 (6.1, 7.5) | <0.05 | ||
| 12.9 | 12.3 | ||||
| Abdominal | 5.5 (4.5, 6.5) | 4.8 (4.1, 5.7) | NS | ||
| 11.6 | 11.6 | ||||
| Group 4 | Overall | 8.2 (7.5, 8.9) | 6.5 (5.9, 7.1) | <0.05 | |
| 13.1 | 11.7 | ||||
| Thoracic | 9.5 (8.6, 10.4) | 7.5 (6.7, 8.2) | <0.05 | ||
| 12.5 | 11.7 | ||||
| Abdominal | 6.2 (5.0, 7.5) | 5.2 (4.0, 6.4) | NS | ||
| 13.1 | 10.9 | ||||
NS = not significant.
Group 1: PET1, PET2, PET3; Group 2: PET1, PET2, PETSCANNER or PETALGO; Group 3: PET1, PET3, PETSCANNER or PETALGO; Group 4: PET2, PET3, PETSCANNER or PETALGO.