Size and Severity of Misregistration Artifacts
| PET/CT (n = 122) | Severity | Size–severity | % ≤ 2.0 SD | % ≤ 2.5 SD | Transaxial misregistration (mm) | n |
|---|---|---|---|---|---|---|
| NA | 79.6 ± 3.1 | 0.1 ± 0.2 | 2.5 ± 3.1 | 0.8 ± 1.1 | 2.4 ± 2.4 | 19 |
| Artifacts | 73.9 ± 6.4 | 6.2 ± 14.6 | 8.6 ± 4.9 | 6.1 ± 4.9 | 11.7 ± 5.0 | 103 |
| P for Δ | 0.0000 | 0.0000 | 0.0000 | 0.0000 | 0.0000 | |
| Mild artifact | 75.9 ± 3.9 | 1.8 ± 3.6 | 6.8 ± 3.9 | 3.9 ± 3.5 | 10.2 ± 3.8 | 44 |
| P for Δ vs. NA | 0.0003 | 0.0024 | 0.0000 | 0.0000 | 0.0000 | |
| Moderate artifact | 74.2 ± 5.3 | 3.8 ± 5.3 | 9.3 ± 5.0 | 6.8 ± 4.7 | 12.1 ± 5.0 | 50 |
| P for Δ vs. NA | 0.0000 | 0.0000 | 0.0000 | 0.0000 | 0.0000 | |
| Severe artifact | 62.9 ± 10.3 | 41.07 ± 31.1 | 13.9 ± 3.8 | 12.3 ± 4.8 | 16.5 ± 7.3 | 9 |
| P for Δ vs. NA | 0.0011 | 0.0043 | 0.0000 | 0.0001 | 0.0003 | |
| No or mild artifact | 77.0 ± 4.1 | 1.3 ± 3.1 | 5.5 ± 4.2 | 2.9 ± 3.3 | 7.9 ± 4.9 | 63 |
| Moderate or severe artifact | 72.4 ± 7.4 | 9.5 ± 18.4 | 10.0 ± 5.1 | 7.7 ± 5.1 | 12.8 ± 5.6 | 59 |
| P for Δ vs. no or mild | 0.0001 | 0.0013 | 0.0000 | 0.0000 | 0.0000 |
NA = no artifacts.
All patients with perfusion defects outside 2 SD from healthy subjects on final stress PET/CT images, considered to be “real” defects, were excluded from quantitative analysis of misregistration artifacts in this table.