Table 2.
Quantitative assessment of artifact reduction and surrounding liver parenchyma.
| Corrected attenuation | Corrected image noise | |||
|---|---|---|---|---|
| Hyperdense artifact | Hypodense artifact | Surrounding liver parenchyma | ||
| CI | 337.9 ± 104.2 | (−)479.2 ± 132.0 | 75.8 ± 25.5 | 7.0 ± 5.7 |
| 40 keV | 1251.4 ± 380.4 | (−)1074.6 ± 90.1 | 251.5 ± 101.6 | 34.1 ± 27.4 |
| 50 keV | 772.7 ± 295.5 | (−)928.5 ± 149.4 | 160.3 ± 62.8 | 19.4 ± 13.6 |
| 60 keV | 508.9 ± 176.2 | (−)711.3 ± 155.3 | 106.6 ± 40.7 | 18.4 ± 30.8 |
| 70 keV | 330.1 ± 128.3 | (−)516.4 ± 138.4 | 74.5 ± 28.5 | 8.1 ± 6.7 |
| 80 keV | 230.4 ± 82.7 | (−)378.2 ± 121.0 | 54.2 ± 22.2 | 5.6 ± 5.5 |
| 90 keV | 160.4 ± 63.0 | (−)284.1 ± 107.9 | 41.0 ± 19.1 | 4.5 ± 4.7 |
| 100 keV | 113.0 ± 52.5 | (−)218.8 ± 100.0 | 32.3 ± 17.6 | 4.0 ± 4.4 |
| 110 keV | 79.2 ± 47.9 | (−)173.2 ± 95.5 | 25.7 ± 17.3 | 3.8 ± 4.3 |
| 120 keV | 54.9 ± 46.2 | ( −)139.9 ± 93.5 | 21.1 ± 17.2 | 5.0 ± 7.9 |
| 130 keV | 36.8 ± 46.0 | ( −)115.2 ± 92.7 | 17.7 ± 17.3 | 3.8 ± 4.4 |
| 140 keV | 23.0 ± 46.5 | ( −)96.1 ± 92.4 | 15.1 ± 17.5 | 3.9 ± 4.5 |
| 150 keV | 12.1 ± 47.3 | ( −)73.2 ± 105.9 | 13.0 ± 17.7 | 3.9 ± 4.6 |
| 160 keV | 3.6 ± 48.1 | ( −)69.6 ± 92.7 | 11.5 ± 17.9 | 4.2 ± 4.4 |
| 170 keV | (-)3.3 ± 48.9 | ( −)60.1 ± 92.9 | 10.2 ± 18.0 | 4.1 ± 4.7 |
| 180 keV | (-)9.0 ± 49.7 | ( −)52.4 ± 93.2 | 9.1 ± 18.2 | 4.1 ± 4.7 |
| 190 keV | (-)12.2 ± 49.5 | ( −)44.6 ± 94.5 | 7.9 ± 20.5 | 4.1 ± 4.7 |
| 200 keV | (-)17.5 ± 51.0 | ( −)40.7 ± 93.7 | 7.5 ± 18.1 | 4.1 ± 4.8 |
| P values | ||||
| CI vs. 40–50 keV | P < 0.001 | P < 0.001 | P < 0.001 | P < 0.001 |
| CI vs. 60 keV | P < 0.001 | P < 0.001 | P > 0.05 | P < 0.001 |
| CI vs. 70 keV | P > 0.05 | P > 0.05 | P > 0.05 | P > 0.05 |
| CI vs. 80 keV | P > 0.05 | P < 0.001 | P > 0.05 | P > 0.05 |
| CI vs. 90–200 keV | P < 0.001 | P < 0.001 | P < 0.001 | P > 0.05 |
CI conventional images.
Data in italics indicate no statistical significance between any two energy levels.