Table 1.
Contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR) and quantification bias (based on Eq. 8) calculated for spheres #1–#6 corresponding to the smallest to the largest spheres in the Jaszczak phantom
| Sphere | #1 | #2 | #3 | #4 | #5 | #6 |
|---|---|---|---|---|---|---|
| OSEM | ||||||
| Bias (%) | 29.2 | 27.4 | 25.2 | 25.1 | 24.3 | 22.3 |
| SNR | 20.2 | 21.0 | 21.7 | 22.6 | 23.0 | 22.8 |
| CNR | 5.9 | 6.2 | 8.2 | 9.1 | 8.2 | 9.1 |
| Gaussian | ||||||
| Bias (%) | 35.4 | 32.6 | 30.7 | 28.5 | 27.0 | 24.7 |
| SNR | 25.1 | 25.9 | 26.4 | 26.9 | 27.3 | 27.2 |
| CNR | 6.3 | 8.4 | 11.3 | 14.3 | 14.1 | 13.5 |
| Bilateral | ||||||
| Bias (%) | 33.3 | 31.3 | 28.6 | 27.4 | 26.2 | 24.3 |
| SNR | 26.0 | 26.3 | 27.8 | 28.0 | 28.4 | 28.4 |
| CNR | 8.8 | 10.0 | 15.1 | 17.5 | 17.7 | 18.3 |
| NLM | ||||||
| Bias (%) | 32.0 | 30.9 | 28.1 | 27.2 | 25.9 | 23.9 |
| SNR | 27.9 | 28.3 | 29.1 | 31.3 | 31.4 | 31.5 |
| CNR | 12.9 | 13.1 | 17.8 | 21.6 | 22.1 | 24.1 |
| MR-NLM | ||||||
| Bias (%) | 31.1 | 29.7 | 29.0 | 26.6 | 25.1 | 23.1 |
| SNR | 28.8 | 29.9 | 30.1 | 32.5 | 32.6 | 32.7 |
| CNR | 13.8 | 13.9 | 18.8 | 22.6 | 22.9 | 24.9 |
| p value | ||||||
| Bias (%) | 0.04 | 0.03 | 0.01 | 0.04 | 0.04 | 0.05 |
| SNR | 0.02 | 0.01 | 0.02 | 0.01 | 0.03 | 0.04 |
| CNR | 0.03 | 0.05 | 0.02 | 0.03 | 0.05 | 0.06 |