| Autor: |
Nishikawa, Keiichi, Mori, Toshimichi, Shibuya, Hitoshi, Hayakawa, Yoshihiko, Wakoh, Mamoru, Kuroyanagi, Kinya |
| Zdroj: |
Oral Radiology; Dec1999, Vol. 15 Issue 2, p125-133, 9p |
| Abstrakt: |
We evaluated the dose response of two storage-phosphor systems, DenOptix and Digora, for intra-oral radiography. Dose response curves were generated using uniform flat field exposure. The dynamic range of both systems was assessed. Root mean square (RMS) granularity curves were also generated to compare noise levels at different exposures. For DenOptix, curves were obtained by activating and inactivating the automatic range control (ARC) setting. For Digora, curves were generated at different calibration exposures. Moreover, tube voltage and tube current dependencies in both systems were examined. In the dose response curve of the DenOptix with the activated ARC setting, the pixel value was kept almost constant regardless of exposure. The dose response curve of the Digora was changed by the different calibration exposures. The curves at relatively large calibration exposures had inflection points and the pixel value gradually decreased at exposures higher than the inflection points. These results clearly show that the DenOptix with the activated ARC setting, as well as the Digora, can produce images with identical density, regardless of exposure. The dynamic range of both storage-phosphor systems was significantly greater than that of CCD-based systems. With both DenOptix and Digora, higher exposure decreased relative noise levels. The sensitivity of both systems increased with higher tube voltage, although tube current dependency was not observed. Both systems allow for a dose reduction due to a high tube voltage. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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