Table 1.
Hounsfield Units (HUs), mass density and relative electron density at the levels of sternoclavicular joint, carina, and at 2 cm above the upper part of the diaphragm, for the lung in FB and DIBH respiratory phase, respectively.
| Respiratory Phase | Parameters | Sternoclavicular |
Carina |
2 cm above diaphragm |
Average (Mean ± SD) |
|---|---|---|---|---|---|
| Free-breathing (FB) |
Hounsfield Units (HU) |
−757.5 ± 22.5 |
−779.1 ± 44.3 |
−809.8 ± 30.3 |
−782.1 ± 24.8 |
| Mass density (g/cc) |
0.221 ± 0.023 |
0.199 ± 0.045 |
0.168 ± 0.030 |
0.196 ± 0.025 |
|
| Relative Electron density |
0.243 ± 0.023 |
0.221 ± 0.044 |
0.190 ± 0.030 |
0.218 ± 0.025 |
|
| Deep-breathing (DIBH) |
Hounsfield Units (HU) |
−860.4 ± 26.2 |
−895.2 ± 31.1 |
−894.8 ± 31.9 |
−883.5 ± 24.9 |
| Mass density (g/cc) |
0.118 ± 0.026 |
0.083 ± 0.031 |
0.083 ± 0.032 |
0.083 ± 0.032 |
|
| Relative Electron density |
0.140 ± 0.026 |
0.105 ± 0.031 | 0.105 ± 0.032 |
0.117 ± 0.025 |