Table 4.
CNR of the optical nerve and inferior rectus muscle.
| Scanner | CTDIvol (mGy) | Reconstruction technology | Kernel | Optical nerve CNR (SD) | Inferior rectus muscle CNR (SD) |
|---|---|---|---|---|---|
| Reference scanner | 2.66 | FBP | standard | 2.80 (1.72) | 2.36 (1.14) |
| VEO | standard | 10.18 (2.47) b | 8.25 (2.91) a | ||
| NR40 | 16.36 (3.03) b | 10.60 (4.45) b | |||
| Test scanner 1 | 2.65 | FBP | H30f | 4.49 (0.75) | 2.89 (0.60) |
| 1.92 | FBP | H30f | 3.98 (0.91) | 4.19 (1.53) | |
| Test scanner 2 | 2.65 | FBP | H30f | 4.17 (0.87) | 4.67 (3.25) |
| SAFIRE 3 | J30f | 5.12 (1.41) | 5.47 (3.58) | ||
| SAFIRE 5 | J30f | 5.90 (1.91) | 6.01 (3.64) | ||
| 1.73 | FBP | H30f | 3.40 (0.81) | 3.25 (1.33) | |
| SAFIRE 3 | J30f | 4.32 (1.08) | 3.92 (1.69) | ||
| SAFIRE 5 | J30f | 5.08 (1.41) | 3.25 (2.03) |
CNR, contrast-to-noise ratio; FBP, filtered back projection; LDP, low dose protocol; SAFIRE, Sinogram Affirmed Iterative Reconstruction; SD, standard deviation.
a
Statistically significant (p < 0.05) difference to the reference scanner protocol FBP standard.
b
Statistically significant (p < 0.001) difference to the reference scanner protocol FBP standard.