Table 1.
3D cone‐beam CT scanning parameters and reconstructed volumes of the various tested spine protocols on Philips hCBCT and O‐arm mCBCT for spine intraoperative imaging
| hCBCT 27 cm | hCBCT 37 cm | hCBCT 48 cm | mCBCT LD | mCBCT SD | mCBCT HD | |
|---|---|---|---|---|---|---|
| Gantry size (cm) | 85 | 70 | ||||
| x‐ray focal spots size (mm) | 0.4 and 0.7 | 0.6 and 1.2 | ||||
| Detector size (cm) | 40 × 30 | 40 × 30 | ||||
| Detector pixel matrix | 2480 × 1920 | 2038 × 1536 | ||||
| Pixel size (mm) | 0.154 | 0.194 | ||||
| Detector 3D digital data conversion (bits) | 16 | 12 | ||||
| 3D scan rotation (degrees) | 180 | 360 | ||||
| Number of projections | 482 | 302 | 302 | 391 | 391 | 750 |
| 3D scan time (sec) | 8 | 10 | 10 | 13 | 13 | 25 |
| Cu beam filtration (mm) | 0.4 | 0.1 | ||||
| Antiscatter grid ratio | 15:1 | 12:1 | ||||
| kV | 120 | 120 | ||||
| mAs | Variable based on estimated patient thickness by the AEC. Ranges within 50–325 | 64/80/160/200 for S/M/L/XL thickness | 128/200/320/400 for S/M/L/XL thickness | 188/300/480/600 for S/M/L/XL thickness | ||
| CBCT matrix size | 2563 | 3833 | 5122 × 396 | 5122 × 198 | ||
| CBCT voxel size (mm3) | 0.4923 | 0.4523 | 0.4923 | 0.415 × 0.415 × 0.833 | ||
| CBCT diameter‐length (cm) | 12.6–12.6 | 17.3–17.3 | 25.2–19.5 | 21.2–16.5 | ||
LD, low dose; SD, standard dose; HD, high dose; S, small; M, medium; L, large; XL, extra large; AEC, automatic exposure control; CBCT, cone‐beam computed tomography.