Abdominal MDCT “standard-dose” protocols utilized in the prospective trial*.
| Protocol: | IV Contrast | Urolithiasis | Supine CTC |
|---|---|---|---|
| Scanner | GE HD750 | GE HD 750 | GE HD 750 |
| Scan Type | Helical | Helical | Helical |
| Rotation Time (sec) | 0.5 | 0.8 | 0.5 |
| Beam Collimation (mm) | 40 | 40 | 40 |
| Detector Rows | 64 | 64 | 64 |
| Pitch | 0.516 | 0.516 | 0.984 |
| Speed (mm/rot) | 20.64 | 20.64 | 39.36 |
| Detector Configuration | 64 × 0.625 | 64 × 0.625 | 64 × 0.625 |
| Slice Thickness for NI (mm) | 1.25 | 1.25 | 1.25 |
| Scan FOV | Large Body | Large Body | Large Body |
| kVp | 120 | 120 | 120 |
| Smart mA Range | 60-660 | 40-660 | 30-300 |
| Noise Index | 24 | 28 | 50 |
| Reconstructions (FBP): | |||
| DFOV | 36-50 | 36-50 | 36-50 |
| Recon Type | Standard | Standard | Standard |
| Window W/L | 400/50 | 400/50 | 400/50 |
| Recon Option | Plus | Plus | Plus |
| Slice Thickness (mm) | 2.5 | 2.5 | 2.5 |
| Interval (mm) | 1.5 | 1.5 | 1.5 |
*
The specific protocol for the accompanying low-dose series was derived by adjusting the noise index (NI)/slice thickness pairing (and mA range) to allow for a targeted 70-90% dose reduction (by DLP) relative to the “standard-dose” series.