Table 1.
Mean radiation exposure, estimated effective dose, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of images under different simulated levels of the original scan
| Mean exposure (mAs) | Mean CDTIVol(mGy) | Effective dose (mSv) | SNR | CNR | |
|---|---|---|---|---|---|
| Original | 109 | 7.5 | 10 | 32.802 | 13.682 |
| Proj50 | 55 | 3.8 | 5 | 21.483 | 8.597 |
| Proj25 | 27 | 1.9 | 3 | 16.193 | 6.336 |
| Proj10 | 11 | 0.8 | 1 | 14.208 | 5.619 |
| Tube50 | 55 | 3.8 | 5 | 18.552 | 7.234 |
| Tube25 | 27 | 1.9 | 3 | 9.524 | 3.794 |
| Tube10 | 11 | 0.8 | 1 | 2.858 | 1.146 |
Proj50, Proj25 and Proj10 represent 50%, 25% and 10% of the sparse sampling, respectively
Tube50, Tube25 and Tube10 represent 50%, 25% and 10% of the simulated lower tube current, respectively
Effective dose was estimated for a female from the shoulder to the middle of the thigh
SNR was estimated within a homogenous region of the material of the highest density in the phantom
CNR was estimated between the homogenous regions of the materials of the highest and lowest density in the phantom