Table 2.
Contrast-to-noise ratios for five test materials in images obtained with the test protocols.
| Scanner | CTDIvol (mGy) | Reconstruction technology | Sharp kernels / Soft kernels | |||
|---|---|---|---|---|---|---|
| AIR | ALU | HA-100 | HA-200 | |||
| Reference scanner | 2.66 | FBP | 4.33/12.42 | 10.82/16.70 | 0.48/1.74 | 1.21/4.40 |
| VEO standard | n.a. / 38.31 | n.a. / 77.58 | n.a. / 6.72 | n.a. / 19.23 | ||
| VEO NR40 | n.a. / 49.93 | n.a. / 96.04 | n.a. / 11.07 | n.a. / 30.70 | ||
| Test scanner 1 | 3.44 | FBP | 5.49/28.41 | 7.34/23.07 | 0.39/2.38 | 1.17/6.00 |
| 2.65 | FBP | 4.27/26.18 | 8.37/14.04 | 0.42/2.43 | 0.99/6.47 | |
| 1.92 | FBP | 3.75/15.46 | 7.63/12.74 | 0.35/2.08 | 0.88/4.41 | |
| 1.03 | FBP | 2.57/13.14 | 5.78/11.55 | 0.31/1.51 | 0.75/4.07 | |
| Test scanner 2 | 3.08 | FBP | 5.47/35.22 | 7.56/28.81 | 0.43/1.99 | 1.09/6.18 |
| SAFIRE 3 | 39.01/55.74 | 26.15/32.28 | 2.19/3.05 | 6.31/9.57 | ||
| SAFIRE 5 | 53.15/75.12 | 26.80/33.56 | 2.86/3.83 | 8.55/13.86 | ||
| 2.65 | FBP | 4.77/28.46 | 7.66/34.53 | 0.42/2.05 | 1.14/5.51 | |
| SAFIRE 3 | 29.84/43.10 | 72.11/83.53 | 1.81/2.42 | 5.17/7.24 | ||
| SAFIRE 5 | 41.70/60.21 | 99.74/117.36 | 2.18/3.01 | 6.54/9.12 | ||
| 1.73 | FBP | 3.37/21.31 | 6.71/34.79 | 0.29/2.10 | 0.81/4.69 | |
| SAFIRE 3 | 24.60/34.01 | 38.61/16.13 | 2.01/2.76 | 4.29/6.31 | ||
| SAFIRE 5 | 32.48/42.68 | 43.95/82.83 | 2.50/3.42 | 5.14/7.45 | ||
| 1.00 | FBP | 2.88/14.80 | 5.93/34.36 | 0.28/1.38 | 0.71/3.61 | |
| SAFIRE 3 | 16.35/16.90 | 35.87/48.83 | 1.27/1.89 | 3.29/4.75 | ||
| SAFIRE 5 | 21.95/23.53 | 46.67/72.57 | 1.60/2.41 | 3.79/5.72 | ||
ALU, aluminium; FBP, filtered back projection; HA, hydroxyapatite; SAFIRE, sinogram-affirmed iterative reconstruction; VEO, Trade name of a model-based iterative reconstruction.