Percent Contrast, Background Variability, and Average Lung Residual for L/B = 4
| Sphere size (mm) | Contrast (%) | Background variability (%) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 2i × 8s* | 4i × 14s† | FBP (relative deviation) | 2i × 8s* | 4i × 14s† | FBP | |||||
| 10 | 22 | 48 | 46 (4.4) | 2.8 | 6.6 | 8.1 | ||||
| 13 | 32 | 51 | 48 (4.1) | 2.3 | 5.8 | 5.7 | ||||
| 17 | 54 | 68 | 65 (5.6) | 2.0 | 5.0 | 4.2 | ||||
| 22 | 65 | 74 | 72 (2.7) | 1.9 | 4.1 | 3.3 | ||||
| 28 | 51 | 68 | 73 (2.6) | 1.8 | 3.3 | 2.2 | ||||
| 37 | 54 | 73 | 73 (4.7) | 2.1 | 3.4 | 1.8 | ||||
| Average residual (%) over lung insert | 34 | 17 | 22 | |||||||