Program Information
Developing a New Protocol for Dosimetry of Dental CBCT
M Ghaedizirgar1,2 , R Faghihi1,3 , R Paydar4 , S Sina3*, (1) School of mechanical engineering, Shiraz University, Shiraz, Iran (2) Shiraz University of medical sciences, Shiraz, Iran (3) Radiation Research Center, Shiraz University, Shiraz, Iran (4) Iran university of medical sciences, Tehran, Tehran,
Presentations
SU-H3-GePD-I-3 (Sunday, July 30, 2017) 4:00 PM - 4:30 PM Room: Imaging ePoster Lounge
Purpose: Dental Cone beam computed tomography is a kind of CT imaging emitting diverging x-rays to large area containing two-dimensional detector. The aim of this study is to develop a new protocol for dental CBCT dosimetry, for establishing the diagnostic reference levels for this modality of imaging.
Methods: CT head phantom was used with a 10mm pencil beam dosimeters for dosimetry of CBCT. first the CTDI in air was obtained for different field sizes and kVps. Then the CTDI was measured in the CTDI head phantom.
Results: The developed protocol consisted of (1) measurement of CTDI free in air with 4mm reference beam width. (2) Measurement of CTDI free in air for other beam widths. (3) developing a correction factor by dividing the results of steps 1, and 2, (4) Measurement of CTDI in head phantom. (4) applying the correction factor obtained in step 3 to the CTDI obtained for the phantom. (5) Applying the correction factors for beam divergence and scattering, obtained by Monte Carlo simulations.
Conclusion: The new protocol can be used for the dosimetry of dental CBCT, and obtaining the DRL for this kind of imaging.
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