The Research Of Estimating Patients' Radiation Dose With Monte Carlo Software During Coronary Computed Tomography Angiography

PART 1 Application of Monte Carlo Software in Estimating Patients' Radiation Dose during CCTA and confirmation by Anthropomorphic phantomObjective: Evaluate the accuracy and efficiency of the Monte Carlo software by measure the radiation dose of the patients who received the CCTA(Coronary Computed Tomography Angiography)examination applying the Monte Carlo software.Materials and methods: use Computer Software Impact Dose2.0 to computate the chest organ dose on the basis of the CT scan characteristic,and verified the analogy consequence of Impact Dose2.0 software statistically by Anthropomorphic phantom thermolu minescence dosimeter experiment method.Results: the organ absorbed dose and effective dose of three groups of tube tension CCTA measured by the Impact Dose2.0 analogy procedure is a little lower than that measured by Simulation of Anthropomorphic phantom.Conclusion the tolerance interval of the organ dose survey precision of the patients who receive the coronary artery CCTA examination is between-50% and 50%.PART 2 Estimation of Patients' Radiation Dose during high-pitch and standard-pitch CCTA using Monte Carlo SoftwareObjective: To evaluate the application values of Monte Carlo mathematical model in predicting of patients' radiation dose during high-pitch and standard-pitch Coronary Computed Tomography Angiography(CCTA).Materials and methods: We retrospectively collected the data of 61 cases underwent high-pitch CCTA on the dual source CT scanner,and according to the Asian standard BMI of WHO they were divided into 3 groups: standard group(12 cases),overweight(41 cases)and obesity group(8 cases).Using Monte Carlo Software to calculate the organ dose of three groups during high-pitch and standard-pitch CCTA,compared the organ dose distribution and effective dose of the three groups during high-pitch and standard-pitch CCTA.Results: Calculated by the Monte Carlo software the organ dose during CCTA reduce about 70% when using high-pitch than using the standard pitch on the dual source spiral CT.The organ dose of heart and thymus decreased most significantly,and the largest decline reached bout 80%.During CCTA the effective doses of all the 3 groups were significantly lower when using high-pitch than using the standard pitch.Conclusion: Monte Carlo mathematical model can effectively predict patients' organ dose and effective dose of different CT imaging technology before the examination,so it can be used to discriminate the impact of different CT scanning technology on patients' radiation dose,and this mathematical model has practical significance in the development of low dose CT.