Accuracy of non-contact semiconductor X-ray analyzer for quality assurance in intraoral radiography: a comparison with ionization chamber dosimeter.

Abstract

The aim of the present study was to evaluate the accuracy of a non-contact semiconductor X-ray analyzer for quality assurance in intraoral radiography, especially a comparison with an ionization chamber dosimeter. Intraoral radiography was performed with intraoral X-ray unit using the dental protocol at our hospital: tube voltage, 70kV; tube current, 7mA. Accuracy of dose and half-value layer (HVL) measurements was analyzed with a non-contact semiconductor X-ray analyzer and an ionization chamber dosimeter. Stability of the semiconductor sensor, effect of scattered radiation, and comparison of measured HVL between the ionization chamber and the semiconductor sensor were analyzed in this study. The values with the semiconductor sensor were tube voltage: 70.3 ± 0.2 kVp (degree of variability: 0.28%), dose: 454.1 ± 12.3μGy (degree of variability: 2.7%), and HVL: 1.91 ± 0.02 mmAl (degree of variability: 1.0%). With collimator, the dose with the semiconductor sensor and the ionization chamber decreased by 2.3 μ Gy and 5.2 μ Gy, respectively. The measured HVL of the semiconductor dosimeter was more than that of ionization chamber, and the semiconductor dosimeter was less than ionization chamber in variation of between without and with collimator. This study indicated the accuracy of a non-contact semiconductor X-ray analyzer for quality assurance in intraoral radiography, especially a comparison with an ionization chamber dosimeter. The semiconductor sensor can be useful for quality assurance in intraoral radiography.