Table 2 Exposure protocols used for assessing subjective image quality, CNR, MTF and effective dose
Protocol nr | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
|---|---|---|---|---|---|---|---|---|---|---|
Tube voltage (kVp) | 80 | 90 | 100 | 110 | 120 | 90 | 90 | 100 | 110 | 120 |
Q (mAs) | 450 | 280 | 200 | 140 | 100 | 100 | 450 | 450 | 300 | 300 |
Tube curr. (mA) | 32 | 40 | 40 | 40 | 32 | 36 | 36 | 32 | 28 | 22 |
Exp. time (s) | 14.1 | 7.0 | 5.0 | 3.5 | 3.1 | 2.8 | 12.5 | 14.1 | 10.7 | 13.6 |
Voxel (µm) | 75 | 75 | 75 | 75 | 75 | 75 | 75 | 75 | 75 | 75 |
Scan angle | 210º | 210º | 210º | 210º | 210º | 210º | 210º | 210º | 210º | 210º |
Pulsed | yes | yes | yes | yes | yes | yes | yes | yes | yes | yes |
Frame number | 500 | 500 | 500 | 500 | 500 | 500 | 500 | 501 | 501 | 502 |
FOV height (mm) | 50 | 50 | 50 | 50 | 50 | 50 | 50 | 50 | 50 | 50 |
FOV diameter (mm) | 50 | 50 | 50 | 50 | 50 | 50 | 50 | 50 | 50 | 50 |
CNR | 10.5 | 10.3 | 10.1 | 8.6 | 7.9 | 5.3 | 12.4 | 14.2 | 13.5 | 14.3 |
MTF | 1.49 | 1.54 | 1.60 | 1.60 | 1.62 | 1.51 | 1.50 | 1.41 | 1.55 | 1.57 |
FOM | 2.1 | 2.0 | 1.8 | 1.4 | 1.2 | 1.5 | 1.8 | 1.6 | 1.6 | 1.3 |
Effective dose (µSv) | 52.8 | 53.8 | 56.0 | 52.7 | 52.7 | 19.2 | 86.5 | 125.9 | 112.9 | 158.0 |