Table 2.
Quantitative image analysis (signal intensity, noise, CNR, and SNR).
| Parameter | Dual-energy CCTA (n = 49), mean ± SD | Standard CCTA (n = 53), mean ± SD | P value |
|---|---|---|---|
| Signal intensity (HU) | |||
| Left main | 324.8 ± 94.2 | 429.4 ± 130.3 | <.001 |
| Left anterior descending | 307.3 ± 85.9 | 420.2 ± 120.5 | <.001 |
| Left circumflex | 301.9 ± 84.6 | 430.1 ± 118.6 | <.001 |
| Right coronary | 301.4 ± 90.2 | 436.3 ± 123.8 | <.001 |
| Noise (HU) | |||
| Left main | 25.5 ± 9.5 | 28.7 ± 12.7 | .15 |
| Left anterior descending | 29.4 ± 15.5 | 32.2 ± 18.9 | .42 |
| Left circumflex | 28.8 ± 13.0 | 38.0 ± 20.7 | <.05 |
| Right coronary | 26.3 ± 11.8 | 35.2 ± 20.9 | <.05 |
| SI and noise measurements | |||
| Mean signal intensity (HU) | 308.4 ± 84.4 | 429.0 ± 119.5 | <.001 |
| Mean noise (HU) | 27.5 ± 8.9 | 33.5 ± 14.0 | <.05 |
| CNR | 16.8 ± 5.2 | 16.9 ± 4.8 | .95 |
| SNR | 12.0 ± 3.9 | 13.8 ± 3.9 | .02 |
| SNR (after multivariate analysis) | 12.0 ± 3.9 | 13.8 ± 3.9 | .13 |
CCTA, coronary CT angiography; CNR, contrast-to-noise ratio; HU, Hounsfield units; SD, standard deviation; SNR, signal-to-noise ratio.