Tissue Weighting Factors and Dose Coefficients for 18F-FDG PET (ΓTFDG) and Whole-Body CT (ΓTCT) Scans
| Organ T | wT* | ΓTFDG† (μGy/MBq) | wT · ΓTFDG (μSv/MBq) | ΓTCT‡ | wT · ΓTCT‡ (mSv/mGy) |
|---|---|---|---|---|---|
| Gonads§ | 0.20 | 13.5 | 2.70 | 1.41 ± 0.06 | 0.28 ± 0.01 |
| Red bone marrow | 0.12 | 11 | 1.32 | 1.28 ± 0.04 | 0.153 ± 0.005 |
| Colon | 0.12 | 13 | 1.56 | 1.53 ± 0.05 | 0.184 ± 0.007 |
| Lungs | 0.12 | 10 | 1.20 | 1.45 ± 0.07 | 0.174 ± 0.009 |
| Stomach | 0.12 | 11 | 1.32 | 1.45 ± 0.06 | 0.174 ± 0.007 |
| Bladder | 0.05 | 160 | 8.00 | 1.38 ± 0.07 | 0.069 ± 0.003 |
| Breast | 0.05 | 6.8 | 0.34 | 1.44 ± 0.08 | 0.072 ± 0.004 |
| Liver | 0.05 | 11 | 0.55 | 1.58 ± 0.07 | 0.079 ± 0.003 |
| Esophagus | 0.05 | 11 | 0.55 | 1.43 ± 0.07 | 0.072 ± 0.003 |
| Thyroid | 0.05 | 10 | 0.50 | 2.4 ± 0.1 | 0.123 ± 0.006 |
| Skin | 0.01 | 8 | 0.08 | 0.66 ± 0.03 | 0.007 ± 0.001 |
| Bone surfaces | 0.01 | 11 | 0.11 | 0.86 ± 0.03 | 0.009 ± 0.001 |
| Remaining organs | 0.05 | 11 | 0.55 | 1.37 ± 0.05 | 0.069 ± 0.002 |
| Uterus¶ | — | 21 | — | 1.11 ± 0.04 | — |
| Total | — | — | 19 | — | 1.47 ± 0.02 |
↵* Tissue weighting factors from ICRP Publication 60 (12).
↵† Dose coefficients from ICRP Publication 80 (11).
↵‡ Mean ± SEM.
↵§ Since testes were not in the body region scanned in CT, absorbed doses to gonads were defined as that to ovaries.
↵¶ Although the uterus belongs to the remaining organs, dose coefficients are also given for this organ because uterine dose is often used as surrogate for embryonic dose in the early stage of pregnancy.
Dose coefficients for CT were estimated according to Equation 2 from TLD measurements performed on Alderson phantom.