EDE Rates and EDE Estimates for Typical Transmission Scanning Sources and Configurations
| Isotope or source | γ-Factor (mSv·m2/GBq·h) | Source geometry | Imaging modality | Typical total source strength (GBq) | EDE rate (μSv/GBq·h) | Typical EDE/examination (μSv) | Reference |
|---|---|---|---|---|---|---|---|
| 99mTc | 0.022 | Sheet | SPECT | 0.1–0.3 | 750 | 75 (brain) | 132 |
| Sheet, uncollimated | SPECT | 0.15–0.85 | 71.1 | — (cardiac) | 77 | ||
| HR collimation | SPECT | 0.15–0.85 | 0.8 | — (cardiac) | 77 | ||
| Line | SPECT | 0.37–0.74 | 71.1 | 17.5 (brain) | 41 | ||
| 57Co | 0.021 | Sheet | SPECT | 0.15–0.25 | 324.3 | 27 (cardiac) | 133 |
| 153Gd | 0.029 | Sheet | SPECT | 1–2.5 | 133.3 | 111 (cardiac) | 72 |
| Line, collimated | SPECT | 1–22 | 0.5 | 3.8 (brain) | 131 | ||
| Line, collimated | SPECT | 1.9 | 13.9 (cardiac) | 131 | |||
| Line, uncollimated | SPECT | 32 | 234.7 (brain) | 41 | |||
| 241Am | 0.019 | Line | SPECT | 4–8 | 90 | 240 (brain) | 71 |
| 201Tl | 0.018 | Line | SPECT | 0.15–0.3 | 50.3 | 5 (brain) | 41 |
| 133Ba | 0.085 | Point | SPECT/PET | 0.4–0.6 | 101 | 22.2 (whole body) | 134 |
| 68Ga/68Ge | 0.149 | Rod | PET | 0.2–0.6 | 270 | 54 (brain) | 131 |
| PET | 770 | 154 (cardiac) | 131 | ||||
| 137Cs | 0.092 | Point | PET | 1–1.3 | 170 | 74 (whole body) | 135 |
| X-ray CT | — | X-ray tube | SPECT/PET | — | — | 5,400 (thoracic) | 136 |
EDE is calculated for maximal activity reported and typical 20-min scan except CT.