Proceedings of the Korean Society of Medical Physics Conference (한국의학물리학회:학술대회논문집)
- 2002.09a
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- Pages.294-297
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- 2002
A Method for Simultaneous Measurement of Air Kerma, Half Value Layer and Tube Potential in Quality Control Procedure of Diagnostic x ray units
- Katoh, Tsuguhisa (School of Radiologic Science, Tokyo Metropolitan University of Health Sciences) ;
- Saitoh, Hidetoshi (School of Radiologic Science, Tokyo Metropolitan University of Health Sciences) ;
- Ohtani, Hiroki (School of Radiologic Science, Tokyo Metropolitan University of Health Sciences) ;
- Negishi, Tooru (School of Radiologic Science, Tokyo Metropolitan University of Health Sciences) ;
- Myojoyama, Atsushi (School of Radiologic Science, Tokyo Metropolitan University of Health Sciences) ;
- Ohno, Yuusuke (School of Radiologic Science, Tokyo Metropolitan University of Health Sciences) ;
- Sasaki, Takehito (Oral and Maxillofacial Radiology, Division of Oral Health Sciences, Graduate School)
- Published : 2002.09.01
Abstract
For the quality control procedure of diagnostic x ray units, a method for simultaneous measurement of air kerma, half value layer and tube potential was developed utilizing a computed radiography system for intraoral radiography and film badge case. The response of average pixel values under the windows were calibrated by x rays generated at tube potentials from 40 to 140 kV with filtration from 1.5 to 3.7 mmAl. The calibration curves for half value layer and tube potential were derived as functions of attenuation factors by the 1.4 mmAl filter and the 0.2 mmCu filter. The energy dependency of the open window response was corrected by the calibration factor as a function of the attenuation factor by the 1.4 mmAl filter. The uncertainty of the estimated half value layer, tube potential and air kerma were 0.2 mmAl, 3.6 % and 5 %, respectively. It was thus suggested that this system could be applied to quality control program to detect the variation of working condition of x ray units in clinical use.
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