Table 6 Comparison between “low-dose” and “ultra-low-dose” CT protocols in this study and previous “low-dose” CT protocols
Previous studies | Current study | |||||
|---|---|---|---|---|---|---|
Tabatabaei et al. [17] | Dangis et al. [18] | Bahrami-Motlagh et al. [19] | Shiri et al. [20] | Routine low dose | Suggested new ultra-low dose | |
Number of patients | 20 | 192 | 163 | - | 250 | 250 |
Age (mean) | - | 67 years | - | - | 50 years | 50 years |
Weight | - | - | - | - | 84 kg | 84 kg |
kV | 120 | 100 | 110–120 | 90 | 120 | 120 |
mA | 30 | 20 | 20–30 | 20–45 | 60 | 30 |
Pitch | 1 | 1.2 | 1.4–1.5 | 0.8 | 1.4 | 1.4 |
Rotation time | - | 0.5 | 0.6–0.75 | - | 0.75 | 0.75 |
Slice thickness | 3 | - | - | - | 5 | 5 |
Slice thickness recon | - | 1 | - | - | 1.5 | 1.5 |
FOV | - | 450 | - | - | 350 | 350 |
IOA | 98–99% | 92–98% | - | - | 100% | 97–100% |
CTDIvol (mGy) | 3.5 | 1.3 | 1.8 | 0.7 | 1.6 ± 0.4 | 1.1 ± 0.3 |
DLP (mGy.cm) | 112 | 40 | 65 | - | 60.9 ± 9.5 | 42.2 ± 7.9 |
Mean effective dose (mSv/mGy cm) | 1.8 | 0.56 | 0.9 | - | 0.85 | 0.59 |
Absolute cancer risk | 0.74 × 10-4 | 0.02 × 10-4 | 0.04 × 10-4 | - | 0.03 × 10-4 | 0.02 × 10-4 |
Accuracy | - | - | 96.6% | - | 95.21% | 91.10–93.84% |