Research On Measurement Of MEQ-CWT By"peak To Valley" Method

The measurement of Pu deposition in the human lung is often finished by measuring Aminstead.The results are deeply influenced by chestwall thickness and its composition.TheMEQ-CWT is frequently got to describe this influence.To measure this parameter, it isnecessary to use medical imaging device scanning the chest to get chestwall thickness, andthen calculate the MEQ-CWT combined with relevant parameters of the muscle and fat.Thismethod is complex, expensive procedures and cannot obtain the MEQ-CWT directly.To solvethis problem,we have a research on the measurement of MEQ-CWT using lung conuter by“peak-to-valley”(PVT)method.In this thesis, we do some search about PVT method, including:1、The PVT method is simplified to two simplified models, we get the function aboutPVT and MEQ-CWT in these two models with MCNP code which proves PVT method isfeasible for the measurement of MEQ-CWT.2、Through reaserchs about the k factor, we get the calculation formula of k factor andverify its accuracy by Monte Carlo simulation.3、Take experimental measurements of the media thickness by PVT method using thepoint-source model. The thickness of Al sheets is measured by designing the program ofexperiment and studying the analyze of spectrums measured by PVT method. The resultsverify the method is practically feasible.4、Research the relationship between MEQ-CWT and Q through lung counting systemand human phantom model. Through the calculation of MEQ-CWT using the theoreticalformula in point-source model, take an analysis of the error and disadvantage of applicationof the theoretical formula, gain the feasible method measuring the MEQ-CWT by peak tovalley method.