Clinical Study
The Influence of Effective Energy on Computed Tomography Number Depends on Tissue Characteristics in Monoenergetic Cardiac Imaging
Table 1
The CT number changes of three materials according to the energy level.
| Polyenergetic images | Tube voltage (kVp) | 100 | 120 | 140 |
| Water (HU) | −3.1 ± 0.3 | −2.2 ± 0.5 | −1.8 ± 0.6 | Oil (HU) | −135.1 ± 0.4 | −119.3 ± 0.2 | −104.0 ± 0.5 | Contrast agent (HU) | 682.0 ± 0.5 | 505.8 ± 0.3 | 329.0 ± 0.1 |
| Monoenergetic images | Effective energy (keV) | 40 | 70 | 100 | 130 | 160 | 190 |
| Water (HU) | −7.0 ± 1.0 | −2.8 ± 0.4 | −1.7 ± 0.6 | −1.3 ± 0.7 | −1.1 ± 0.8 | −1.0 ± 0.8 | Oil (HU) | −228.1 ± 2.9 | −127.0 ± 0.2 | −101.0 ± 0.6 | −91.9 ± 0.8 | −87.9 ± 0.9 | −85.9 ± 1.0 | Contrast agent (HU) | 1738.0 ± 1.7 | 590.5 ± 0.5 | 294.7 ± 0.2 | 191.2 ± 0.2 | 146.3 ± 0.2 | 123.7 ± 0.2 |
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CT: computed tomography.
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