Table 4.
Distributions of CT dose index (CTDIvol) for the CT examinations
| Anatomical regions | CTDIvol (mGy) |
|||||
|---|---|---|---|---|---|---|
| n | Mean | Coefficient of variation (%) | 25th percentile | Median | 75th percentile | |
| Head | ||||||
| Adults | 1018 | 77.4 | 34 | 60.0 | 73.0 | 92.3 |
| Children (5 years) | 589 | 42.7 | 43 | 30.0 | 40.0 | 50.0 |
| Non-helical | ||||||
| Adults | 536 | 81.0 | 34 | 62.4 | 75.3 | 93.9 |
| Children (5 years) | 318 | 43.3 | 43 | 30.7 | 40.0 | 50.0 |
| Helical | ||||||
| Adults | 482 | 73.4 | 34 | 58.6 | 70.9 | 90.4 |
| Children (5 years) | 271 | 42.0 | 43 | 29.8 | 39.0 | 50.8 |
| Chest | ||||||
| Adults | 584 | 13.0 | 66 | 8.7 | 11.5 | 16.2 |
| Children (5 years) | 274 | 9.5 | 93 | 4.0 | 6.6 | 12.0 |
| Abdomen | ||||||
| Adults | 570 | 17.7 | 48 | 12.0 | 16.0 | 21.5 |
| Children (5 years) | 269 | 11.3 | 81 | 5.0 | 8.4 | 14.1 |
All CT examinations (tube voltage values, reconstruction algorithms) have been included.
CTDIvol values in the adult chest and abdomen were calculated using a 32-cm phantom, while the others were calculated using a 16-cm phantom.
n indicates the number of CTDIvol values.