Table 2 CT characteristics of participants in the training and validation sets.
From: Histogram-derived modified thresholds for coronary artery calcium scoring with lower tube voltage
Total (n = 893) | Training set (n = 680) | Validation set (n = 213) | P valuea | |
|---|---|---|---|---|
Heart rates (bpm) | 66.4 ± 11.5 | 66.0 ± 11.4 | 67.7 ± 11.7 | 0.070 |
CTDI (mGy) | ||||
100 kV | 1.9 ± 0.1 | 1.9 ± 0.1 | 1.9 ± 0.1 | 0.234 |
120 kV | 2.8 ± 0.0 | 2.8 ± 0.1 | 2.8 ± 0.0 | 0.622 |
P valueb | < 0.001 | < 0.001 | < 0.001 | |
DLP (mGy * cm) | ||||
100 kV | 30.1 ± 0.8 | 30.1 ± 0.8 | 30.1 ± 0.8 | 0.234 |
120 kV | 42.9 ± 0.6 | 42.9 ± 0.6 | 42.9 ± 0.6 | 0.622 |
P valueb | < 0.001 | < 0.001 | < 0.001 | |
Signal (HU) | ||||
100 kV | 43.4 ± 4.3 | 43.3 ± 4.2 | 43.9 ± 4.3 | 0.073 |
120 kV | 42.1 ± 4.8 | 42.0 ± 4.8 | 42.5 ± 4.7 | 0.114 |
P valueb | < 0.001 | < 0.001 | 0.001 | |
Noise (HU) | ||||
100 kV | 28.2 ± 2.6 | 28.2 ± 2.7 | 28.1 ± 2.5 | 0.809 |
120 kV | 25.9 ± 2.9 | 25.9 ± 2.9 | 26.0 ± 2.8 | 0.955 |
P valueb | < 0.001 | < 0.001 | < 0.001 | |
Signal-to-noise ratio | ||||
100 kV | 1.55 ± 0.20 | 1.55 ± 0.19 | 1.57 ± 0.20 | 0.111 |
120 kV | 1.64 ± 0.24 | 1.63 ± 0.23 | 1.66 ± 0.26 | 0.154 |
P valueb | < 0.001 | < 0.001 | < 0.001 | |
