GANTRY ANGULATION EFFECTS ON CT DOSE ALONG THE Z-AXIS DIRECTION IN HEAD EXAMINATIONS
| Autor: | Mehdi Sohrabi, Fereidoun A. Mianji, Masoumeh Parsi, Reza Paydar |
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| Rok vydání: | 2017 |
| Předmět: |
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Materials science Tomography Scanners X-Ray Computed Radiation Dosage Imaging phantom 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Dosimetry Humans Radiology Nuclear Medicine and imaging Radiometry Radiation Radiological and Ultrasound Technology business.industry Phantoms Imaging Public Health Environmental and Occupational Health Isocenter General Medicine Pencil (optics) 030220 oncology & carcinogenesis Ionization chamber Thermoluminescent Dosimetry Nuclear medicine business Head Monte Carlo Method |
| Zdroj: | Radiation protection dosimetry. 177(4) |
| ISSN: | 1742-3406 |
| Popis: | The purpose of this study was to evaluate the effects of the gantry angulation on dose profiles along the z-axis, the CTDIW value and the CTDIW efficiency in the head examinations. A Monte Carlo simulation model of a GE LightSpeed 16-slice CT scanner was developed by a GATE toolkit. The CTDI100 in air at the isocenter and in a head dosimetry phantom were measured using a pencil ion chamber. Dose profiles were studied in the central and peripheral holes of the head phantom using thermoluminescence LiF disc dosemeters for gantry angulations of 0°, 10° and 20°. Results show a small shift for only the peripheral dose profiles with increasing the gantry angulation (maximum shift of 24 mm at 20°). The peak amplitude of the dose profiles was reduced for both of the central and peripheral holes by ~5%, while the CTDIW values and the CTDIW efficiencies did not change significantly. |
| Databáze: | OpenAIRE |
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