Table 2.
Dual-energy indexes for copper and lead bullets
| Measurements | Mean ± standard deviation or median (interquartile range) | Min | Max | Min | Max | SW test | t test or MW U test | |||
|---|---|---|---|---|---|---|---|---|---|---|
| CT number | ROI position | Dual energy (kVp/kVp) | Copper bullets | Lead bullets | Copper bullets | Lead bullets | p value | p value | ||
| Mean | Core | 80/100 | -0.047 ± 0.020 | -0.035 ± 0.009 | -0.091 | -0.011 | -0.051 | -0.008 | 0.514 | 0.090 |
| 80/120 | -0.068 ± 0.031 | -0.060 ± 0.016 | -0.140 | 0.014 | -0.081 | 0.010 | 0.351 | 0.070 | ||
| 80/140 | -0.059 ± 0.039 | -0.078 ± 0.020 | -0.132 | 0.056 | -0.103 | 0.005 | 0.693 | 0.080 | ||
| 100/120 | -0.021 ± 0.015 | -0.025 ± 0.009 | -0.050 | 0.027 | -0.039 | 0.018 | 0.858 | 0.259 | ||
| 100/140 | -0.013 ± 0.024 | -0.043 ± 0.013 | -0.059 | 0.068 | -0.056 | 0.013 | 0.516 | 0.323 | ||
| 120/140 | 0.008 ± 0.011 | -0.018 ± 0.006 | -0.011 | 0.042 | -0.029 | -0.005 | 0.104 | 0.264 | ||
| Max | Core | 80/100 | -0.038 ± 0.023 | -0.034 ± 0.008 | -0.099 | 0.004 | -0.049 | -0.019 | 0.405 | 0.014* |
| 80/120 | -0.054 ± 0.036 | -0.060 ± 0.014 | -0.139 | 0.017 | -0.079 | -0.016 | 0.880 | 0.016* | ||
| 80/140 | -0.042 (0.074) | -0.076 (0.015) | -0.122 | 0.068 | -0.098 | -0.021 | 0.014* | 0.065 | ||
| 100/120 | -0.016 ± 0.018 | -0.026 ± 0.011 | -0.051 | 0.023 | -0.048 | 0.007 | 0.731 | 0.612 | ||
| 100/140 | -0.005 ± 0.027 | -0.042 ± 0.011 | -0.050 | 0.075 | -0.055 | 0.002 | 0.233 | 0.272 | ||
| 120/140 | 0.011 ± 0.013 | -0.016 ± 0.009 | -0.013 | 0.051 | -0.034 | 0.003 | 0.154 | 0.521 | ||
| Mean | Edge | 80/100 | -0.013 ± 0.031 | -0.019 ± 0.022 | -0.129 | 0.052 | -0.082 | 0.047 | 0.150 | 0.829 |
| 80/120 | 0.015 ± 0.046 | -0.025 ± 0.024 | -0.158 | 0.111 | -0.109 | 0.027 | 0.228 | 0.278 | ||
| 80/140 | 0.053 ± 0.050 | -0.030 ± 0.031 | -0.141 | 0.178 | -0.131 | 0.016 | 0.481 | 0.675 | ||
| 100/120 | 0.028 (0.028) | -0.005 (0.008) | -0.029 | 0.065 | -0.029 | 0.003 | 0.037* | 0.002* | ||
| 100/140 | 0.066 ± 0.025 | -0.011 ± 0.014 | -0.012 | 0.134 | -0.050 | 0.017 | 0.114 | 0.232 | ||
| 120/140 | 0.039 ± 0.011 | -0.004 ± 0.010 | 0.012 | 0.069 | -0.037 | 0.025 | 0.062 | 0.418 | ||
| Max | Edge | 80/100 | -0.004 (0.034) | -0.007 (0.016) | -0.103 | 0.063 | -0.084 | 0.000 | 0.027* | 0.065 |
| 80/120 | 0.028 ± 0.045 | -0.021 ± 0.024 | -0.131 | 0.094 | -0.111 | 0.000 | 0.623 | 0.649 | ||
| 80/140 | 0.069 ± 0.050 | -0.026 ± 0.031 | -0.124 | 0.158 | -0.136 | 0.000 | 0.276 | 0.952 | ||
| 100/120 | 0.032 (0.024) | -0.002 (0.007) | -0.028 | 0.073 | -0.027 | 0.003 | 0.039* | 0.002* | ||
| 100/140 | 0.080 (0.028) | -0.006 (0.015) | -0.021 | 0.121 | -0.052 | 0.002 | 0.017* | 0.002* | ||
| 120/140 | 0.040 (0.011) | -0.002 (0.005) | 0.007 | 0.065 | -0.044 | 0.002 | 0.012* | 0.002* | ||
Min Minimum value, Max Maximum value, ROI Region of interest; SW test Shapiro-Wilk test; MW U test Mann-Whitney U test
*Statistically significant values