What is a physical characteristic value?
グリッドの性能を示す数値です。
Using the method specified in JIS Z4910, the grid measures the transmittance of primary X-rays, scattered X-rays, and total X-rays, and can quantitatively express performance metrics such as the contrast ratio and exposure factor.
By using physical property values, you can see how the image changes when you modify the grid settings.
Physical properties
| Tp (Primary X-ray Transmittance) | – | Determined by the measurement method specified in JIS Z 4910. |
| Ts (Scattered X-ray transmittance) | – | Determined by the measurement method specified in JIS Z 4910. |
| Tt (Total X-ray transmittance) | – | Determined by the measurement method specified in JIS Z 4910. |
| B (Exposure factor) | 1/Tt | The rate of increase in radiation dose resulting from the use of a grid. From the perspective of the subject, a lower value is preferable. |
| K (Contrast Enhancement) | Tp/Tt | Amount of scattered X-rays removed. A higher value results in a sharper, higher-contrast image. |
| Σ (Selectivity) | Tp/Ts | Scatter X-ray removal efficiency. A higher value indicates greater efficiency. |
| Q (Image Improvement Coefficient) | Tp²/Tt | Grid evaluation index. |
