Table 4.
Comparison of CTDI-vol and DLP before and after the introduction of the HDM
| CTDI-vol | DLP | ||||
|---|---|---|---|---|---|
| Pre-HDM | Post-HDM | Pre-HDM | Post-HDM | ||
| Total | Maximum | 43.0 | 36.0 | 967.3 | 962.8 |
| 75th percentile | 29.3 | 25.6 | 604.2 | 531.6 | |
| Median | 24.6 | 22.7 | 495.4 | 412.0 | |
| 25th percentile | 22.5 | 15.3 | 408.4 | 282.2 | |
| Minimum | 12.2 | 7.1 | 59.3 | 95.2 | |
| Mean ± SD | 25.2 ± 4.5 | 21.5 ± 6.9 | 504.5 ± 137.6 | 418.4 ± 152.9 | |
| < 1 year | Maximum | 43.0 | 26.0 | 715.6 | 612.3 |
| 75th percentile | 22.8 | 20.1 | 415.5 | 386.0 | |
| Median | 21.3 | 19.2 | 360.9 | 307.9 | |
| 25th percentile | 18.9 | 12.3 | 305.7 | 231.2 | |
| Minimum | 13.6 | 7.8 | 59.3 | 95.2 | |
| Mean ± SD | 20.8 ± 3.2 | 17.9 ± 4.9 | 359.2 ± 83.2 | 310.5 ± 94.4 | |
| 1 to < 5 years | Maximum | 34.5 | 31.6 | 716.6 | 636.8 |
| 75th percentile | 25.3 | 25.0 | 530.9 | 484.7 | |
| Median | 24.4 | 23.7 | 490.7 | 433.4 | |
| 25th percentile | 23.5 | 13.3 | 447.0 | 273.4 | |
| Minimum | 17.1 | 7.5 | 307.0 | 148.9 | |
| Mean ± SD | 24.4 ± 1.9 | 20.8 ± 5.8 | 493.6 ± 66.9 | 407.7 ± 117.5 | |
| 5 to < 10 years | Maximum | 39.9 | 36.0 | 929.2 | 851.1 |
| 75th percentile | 31.2 | 30.7 | 671.5 | 631.8 | |
| Median | 30.1 | 28.5 | 621.2 | 567.0 | |
| 25th percentile | 26.4 | 21.0 | 552.2 | 418.7 | |
| Minimum | 16.8 | 8.2 | 79.8 | 177.3 | |
| Mean ± SD | 30.0 ± 2.8 | 26.5 ± 6.6 | 628.6 ± 97.5 | 541.2 ± 138.1 | |
| 10 to < 15 years | Maximum | 38.0 | 36.0 | 967.3 | 962.3 |
| 75th percentile | 31.5 | 31.5 | 714.2 | 656.7 | |
| Median | 30.5 | 29.7 | 647.1 | 594.2 | |
| 25th percentile | 28.8 | 16.4 | 603.0 | 375.9 | |
| Minimum | 12.2 | 7.13 | 263.0 | 200.1 | |
| Mean ± SD | 29.5 ± 3.6 | 25.5 ± 8.1 | 648.0 ± 108.2 | 543.4 ± 161.6 | |
CTDI-vol computed tomography dose index volume, DLP dose-length product, HDM half-dose method, SD standard deviation