摘要 :
Coronary computed tomography(CT)angiography is associated with high radiation dose and this has raised serious concerns in the literature.Awareness of various parameters for dose estimates and measurements of coronary CT angiograp...
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Coronary computed tomography(CT)angiography is associated with high radiation dose and this has raised serious concerns in the literature.Awareness of various parameters for dose estimates and measurements of coronary CT angiography plays an important role in increasing our understanding of the radiation exposure to patients,thus,contributing to the implementation of dose-saving strategies.This article provides an overview of the radiation dose quantity and its measurement during coronary CT angiography procedures.
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摘要 :
The preliminary study on absolute measurement of absorbed dose of electron beam was carried out at irradiation processing grade.Two type of calorimeters,graphite and polystyrene,which were made in RISO Laboratory,were used to do d...
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The preliminary study on absolute measurement of absorbed dose of electron beam was carried out at irradiation processing grade.Two type of calorimeters,graphite and polystyrene,which were made in RISO Laboratory,were used to do dynamic irradiation experiments at the energy of 10 MeV.This research was about dose response,repeatability,value transfer method,and so on.The results show that the absorbed dose measured by calorimeters was only connected with electron beam intensity during irradiation.The relationship of absorbed dose and electron beam intensity is shown in Fig.1.The absorbed dose was proportional to the beam intensity at the range of 1-50kGy.
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Background A set of nozzle systems for proton therapy is now being developed at China Institute of Atomic Energy.To real-ize the measurement of beam dose,a set of charge measurement electronics is designed,which is used to measure...
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Background A set of nozzle systems for proton therapy is now being developed at China Institute of Atomic Energy.To real-ize the measurement of beam dose,a set of charge measurement electronics is designed,which is used to measure the output charge signal of the ionization chamber integration plane.Also,the charge measurement device can be used to measure the position information of ion chamber strips just by changing certain parameters.Methods The device realizes the integration and amplification of charge by IVC102,a precise low-noise integrator,and the DSP controls the ADC to collect and process the data.Modbus communication protocol is used to realize communication with the host computer which makes it possible to read data and set the parameter.Results A fixed charge generator is designed to generate 20 pC to 2 nC charge,which is used to test the measuring accuracy of electronics.The results have shown that the accuracy is within 0.62%in the above charge range.Conclusion After experimental tests,the front-end electronics meet the design goal and play a certain pre-test and verification role in the dose and beam position monitoring in the proton therapy system.
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