Sphere diameter (mm) | Sphere-to-background ratio = 4:1 | Sphere-to-background ratio = 8:1 | ||||||
---|---|---|---|---|---|---|---|---|
Contrast recovery (%) | Background variability (%) | Contrast recovery (%) | Background variability (%) | |||||
OSEM mean (max/min) | PSF + TOF mean (max/min) | OSEM mean (max/min) | PSF + TOF mean (max/min) | OSEM mean (max/min) | PSF + TOF mean (max/min) | OSEM mean (max/min) | PSF + TOF mean (max/min) | |
10 | 21.5 (19.1/24.9) | 28.5 (24.3/35.4) | 5.6 (5.2/5.9) | 4.7 (4.0/5.4) | 35.3 (33.9/37.7) | 42.4 (41.1/45.1) | 5.7 (4.9/6.4) | 5.5 (5.3/5.6) |
13 | 33.4 (32.7/34.6) | 42.3 (41.3/43.9) | 4.8 (4.3/5.2) | 4.3 (3.7/4.8) | 51.5 (49.3/54.1) | 63.6 (61.3/65.2) | 5.0 (5.6/5.4) | 4.8 (4.6/5.0) |
17 | 47.8 (46.2/49.7) | 58.4 (56.6/60.1) | 3.9 (3.6/4.3) | 3.7 (3.4/4.0) | 59.6 (58.3/61.3) | 68.9 (68.1/69.3) | 4.1 (4.0/4.4) | 4.1 (3.7/4.3) |
22 | 62.1 (59.7/64.3) | 71.7 (67.8/73.6) | 3.2 (3.0/3.5) | 3.4 (3.2/3.6) | 69.9 (68.8/71.2) | 76.7 (76.1/77.1) | 3.4 (3.4/5.6) | 3.4 (3.1/3.7) |
28 | 61.2 (60.4/61.8) | 70.1 (69.6/71.0) | 2.7 (2.6/3.0) | 3.2 (3.1/3.2) | 61.8 (59.4/64.4) | 70.6 (69.3/71.6) | 2.8 (2.6/3.0) | 2.9 (2.6/3.1) |
37 | 67.9 (65.7/69.3) | 78.3 (76.3/80.2) | 2.3 (2.2/2.4) | 3.0 (2.9/3.1) | 68.2 (68.0/68.6) | 78.5 (78.2/78.7) | 2.1 (1.9/2.4) | 2.5 (2.3/2.6) |
Lung residual % (σ) | 22.8 (1.6) | 12.7 (1.4) | 22.3 (1.5) | 12.2 (1.2) |