Investigation of Temperature Dependence of Polymer Gels for Use with Scanning Magnetic Resonance Imaging
| Autor: | Katsumi Miyamoto, Tatsuya Fujisaki, Yoshikazu Shimada, Hitoshi Sato, Akira Matsumura, Hiraku Fuse, Yoshiyuki Ishimori, Takeji Sakae, Kazuya Shinoda, Takaoki Takanashi, Masahiko Monma, Hiraku Kawamura |
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| Rok vydání: | 2018 |
| Předmět: |
chemistry.chemical_classification
Thermal equilibrium Materials science Dosimeter medicine.diagnostic_test Analytical chemistry Dose accuracy Magnetic resonance imaging Polymer 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine chemistry 030220 oncology & carcinogenesis Total dose medicine Irradiation Beam (structure) |
| Zdroj: | International Journal of Medical Physics, Clinical Engineering and Radiation Oncology. :261-272 |
| ISSN: | 2168-5444 2168-5436 |
| DOI: | 10.4236/ijmpcero.2018.72022 |
| Popis: | Polymer gels are three-dimensional dosimetric tools. The purpose of the present study was to investigate the temperature dependence of polymer gels during scanning Magnetic Resonance Imaging. Prepared gels were irradiated with a 6MV X-ray beam at intensities ranging from 0 to 20 Gy in order to investigate their dose-R2 and dose-R1 responses. Irradiated gels were evaluated from 1.5-T magnetic resonance R2 and R1 images for each 5°C change in temperature from 5°C to 41°C, and then the four-field box technique irradiation plan was used to deliver a total dose of 4 Gy using the same beam weight in each direction to the prepared gels. The profile of the dose map generated from the four-field irradiated gel data at 20°C was then compared with the planned data. The dose-R2 response curve was linear up to 20 Gy at 20°C, with a slope of 1.17 Gy-1˙s-1. The slopes of the fitted curves of the dose-R2 decreased as gel temperature increased. The slopes of the dose-R1 curves were more parallel than the slopes of the dose-R2 curves between 5 and 41°C. The difference in the full width of half maximum of the gel profile data obtained using the four-field box technique at 20°C and the planned data were below 5% on average. The dose map from the irradiated gels obtained using the dose-R2 curve was the same as that from the planned data under the same temperature conditions. Measurement of difference between various temperatures is significant with dose accuracy. It is suitable to evaluate the gel dosimeter under the thermal equilibrium condition, MRI room temperature from the point of view of the stability of the irradiated gels. |
| Databáze: | OpenAIRE |
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