Table 3.
Contrast-noise ratio (CNR) for volumetric imaging and steak artefact index (SI) on X-ray volumetric imaging for different fiducial markers
| Volumetric imaging | Visibility (CNR) | Artefact (SI) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| RP | CIVCO | GA | GA (B) | PM | RP | CIVCO | GA | GA(B) | PM | ||
| CT (slice thickness (mm)) | |||||||||||
| 0.625 | 1.46 | 1.49 | 1.53 | 1.54 | 1.47 | 67.78 | 110.9 | 61.04 | 67.51 | 25.57 | |
| 1.25 | 1.61 | 1.46 | 1.44 | 1.22 | 1.52 | 86.92 | 52.81 | 65.20 | 59.64 | 66.24 | |
| 2.5 | 1.27 | 1.23 | 1.42 | 1.34 | 1.52 | 53.35 | 47.19 | 36.88 | 46.15 | 11.63 | |
| CBCT (protocol) | |||||||||||
| P Varian | 1.17 | 0.96 | 0.99 | 0.92 | 0.79 | 33.16 | 22.03 | 33.81 | 13.86 | 19.55 | |
| P Medium | 0.94 | 0.94 | 0.64 | 1.07 | 0.90 | 26.38 | 42.57 | 15.58 | 19.91 | 9.82 | |
| P Obese | 1.00 | 0.84 | 0.85 | 1.16 | 1.27 | 66.08 | 58.28 | 47.48 | 75.81 | 36.88 | |
| MRI | FM size (mm3) | ||||||||||
| P | 13.57 | 13.57 | 5.03 | 5.03 | 9.42 | ||||||
| T1w | 1.17 | 1.69 | 1.77 | 1.64 | 2.56 | 6.67 | 10.00 | 6.67 | 26.67 | 3.33 | |
| T2w (filtered) | 1.95 | 1.87 | 1.54 | 1.45 | 1.88 | 13.33 | 20.00 | 16.67 | 23.33 | 13.33 | |
| VIBE | 1.58 | 1.94 | 1.57 | 1.47 | 2.10 | 53.33 | 70.0 | 123.33 | 136.67 | 110.00 | |
Note that CNR and SI values are calculated for each box as a contribution of the 3 FMs contained in each box while FM size in MRI corresponds to one FM to facilitate the comparison with their physical dimensions. P indicates the physical size of the markers calculated assuming the markers are perfect cylinders