Table 2. Comparison of dual-energy CT quantitative parameters between benign and malignant lesions of the breast.
| Parameter | Benign | Malignant | t/Z value | P value |
|---|---|---|---|---|
| Arterial phase NIC | 0.024 (0.015, 0.053) | 0.093 (0.060, 0.153) | −7.013 | <0.001a |
| Venous phase NIC | 0.168 (0.072, 0.291) | 0.337±0.138 | −5.346 | <0.001 |
| Arterial phase λHu (HU/keV) | 0.295 (0.043, 0.668) | 1.641±0.823 | −7.688 | <0.001 |
| Venous phase λHu (HU/keV) | 0.829±0.843 | 2.531±0.964 | −11.002 | <0.001b |
| Arterial phase nZeff | 0.690 (0.670, 0.700) | 0.730 (0.700, 0.758) | −6.045 | <0.001 |
| Venous phase nZeff | 0.820 (0.800, 0.838) | 0.880 (0.840, 0.900) | −5.379 | <0.001 |
| Arterial phase Attenuation (HU) | 31.52±13.78 | 54.28±14.84 | −9.713 | <0.001 |
| Venous phase Attenuation (HU) | 37.30±16.61 | 66.59 (55.65, 76.75) | −7.626 | <0.001 |
a, the Mann-Whitney U-test for non-normally distributed data [median (quartile range)]; b, Welch’s t-test for normally distributed continuous data (means ± standard deviation). NIC, normalized iodine concentration; nZeff, normalized effective atomic number; λHu, slope of the spectral Hounsfield unit curve; HU, Hounsfield unit.