Table 1.
Parameters used for the non-contrast brain CT acquisitions
| Parameter | Helical mode (n = 35) | Sequential mode (n = 11) | Volume mode (n = 2) |
|---|---|---|---|
| Tube voltage (kVp) | 120 | 120 | 120 |
| Effective tube current time product (mAs) | 360 | 350 | 140/2251 |
| Rotation time (s) | 0.75 | 1.0 | 0.5/0.751 |
| Collimation (mm) | 0.5 × 40 | 0.5 × 80 | 0.5 × 320 |
| Pitch | 0.625 | n.a. | n.a. |
| CTDIvol (mGy) | 52.7 | 43.2/34.22 | 16.1/25.51 |
1In total, two patients were scanned using volume mode. One with a lower mAs and rotation time than the other
2One patient was scanned using the large field-of-view instead of the default medium field-of-view, resulting in a lower CTDIvol