Table 3. Organ dose (mGy) and effective dose (mSv) obtained in routine adult and paediatric abdominopelvic CT examinations with 64-slice CT scanners.
| Adult CT |
Paediatric CT |
|||||||
| CT scanner | A | B | C | D | A | B | C | D |
| Tube voltage (kV) | 120 | 120 | 120 | 120 | 120 | 120 | 120 | 120 |
| The method of tube current adjustment | Volume EC | Smart mA | Care Dose 4D | D-DOM | Volume EC | Smart mA | Care Dose 4D | Fixed (203 mA) |
| Effective mAsa | 208 | 124 | 251 | 247 | 43 | 28 | 90 | 100 |
| Rotation time (s rotation–1) | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.33 | 0.5 |
| Beam width (mm) | 1.0 mm × 32 | 0.625 mm × 64 | 0.6 mm × 32 | 0.625 mm × 64 | 1.0 mm × 32 | 0.625 mm × 32 | 0.6 mm × 32 | 0.625 mm × 64 |
| Pitch factor | 0.844 | 0.984 | 1.0 | 0.641 | 1.406 | 1.375 | 1.0 | 1.015 |
| Planned scan length (mm) | 440 | 420 | 460 | 425 | 260 | 280 | 275 | 260 |
| Exposed scan length (mm) | 497 | 488 | 492 | 482 | 355 | 314 | 308 | 325 |
| Tissue or organ | Organ dose (mGy) | Organ dose (mGy) | ||||||
| Brainb | – | – | – | – | 0.1 | <0.1 | 0.1 | 0.1 |
| Lensb | – | – | – | – | <0.1 | <0.1 | 0.1 | 0.1 |
| Salivary glandsb | – | – | – | – | 0.1 | <0.1 | 0.1 | 0.2 |
| Thyroid | 0.5 | 0.3 | 0.6 | 0.7 | 0.6 | 0.1 | 0.5 | 0.5 |
| Lung | 12.0 | 7.4 | 12.7 | 12.3 | 6.5 | 2.1 | 6.4 | 6.8 |
| Breast | 17.9 | 11.3 | 14.9 | 16.1 | 10.0 | 0.6 | 3.8 | 7.3 |
| Oesophagus | 13.6 | 5.9 | 12.6 | 13.3 | 6.1 | 1.8 | 6.3 | 6.4 |
| Liver | 27.1 | 11.5 | 21.9 | 24.9 | 8.5 | 4.5 | 12.2 | 12.2 |
| Stomach | 31.0 | 11.9 | 22.2 | 29.6 | 7.9 | 4.6 | 12.3 | 13.7 |
| Colon | 31.3 | 15.1 | 23.9 | 26.6 | 8.2 | 5.4 | 12.2 | 13.1 |
| Ovaries | 31.1 | 19.6 | 28.7 | 22.9 | 8.1 | 5.2 | 12.3 | 11.2 |
| Bladder | 32.6 | 17.3 | 27.5 | 20.1 | 8.6 | 5.2 | 11.3 | 11.3 |
| Testes | 21.0 | 6.5 | 7.2 | 10.3 | 6.5 | 3.2 | 3.7 | 8.9 |
| Bone surface | 29.4 | 17.8 | 23.4 | 21.2 | 10.1 | 4.4 | 9.7 | 8.2 |
| Red bone marrow | 14.4 | 8.2 | 12.6 | 11.8 | 4.1 | 1.8 | 4.8 | 3.9 |
| Skin | 5.8 | 4.0 | 5.0 | 6.1 | 1.0 | 1.2 | 2.0 | 2.5 |
| ICRP 103 | ||||||||
| Remainder tissues | 21.3 | 9.9 | 16.5 | 19.1 | 6.2 | 3.4 | 8.7 | 8.7 |
| Effective dose (mSv) | 20.7 | 10.3 | 16.6 | 17.8 | 6.8 | 3.0 | 7.8 | 8.5 |
| ICRP 60 | ||||||||
| Remainder tissues | 22.1 | 9.7 | 16.8 | 19.7 | 6.1 | 3.4 | 8.8 | 8.7 |
| Effective dose (mSv) | 21.9 | 10.7 | 17.2 | 18.0 | 6.8 | 3.3 | 8.1 | 8.9 |
| CTDIvol (mGy) | 22.9 | 10.3 | 18.1 | 17.6 | 4.2 | 2.2 | 5.2 | 5.9 |
| DLP (mGy cm) | 1138 | 503 | 891 | 848 | 148 | 69 | 160 | 192 |
CTDI, CT dose index; DLP, dose–length product; ICRP, International Commission on Radiological Protection.
a
 |
bDoses not measured for the adult phantom were assumed to be zero.