Monte Carlo Simulation Of In Vivo Measurement Of The Most Suitable Knee Position For The Most Optimal Measurement Of The Activity

Monte Carlo Simulation of In-vivo Measurement of the Most Suitable Knee Position for the Most Optimal Measurement of the Activity

Internal contamination of 241 Am is commonly detected and assessed by direct counting of gamma emissions in the region of the body that has high bone content and low surrounding tissue masses; for examples the skull or the knee. To assess the amount of activity in the knee, and then to calculate it in the skeleton, a suitable position of the leg by which all the knee bones contribute to detectable activity should be found. The aim of this study is to create a new and valid model for Monte Carlo simulation of in-vivo measurements of the knee, a model can be used to determine a position that optimizes conventional measurements. The United States Transuranium and Uranium Registries (USTUR) case 0846 is a whole-body donation; its body size is very close to reference man body dimensions. It may provide a unique opportunity to determine the full-lifetime biokinetics of 241Am Oxide chronic inhalation. A new leg voxel model in two different positions (straight and bent) was constructed based on CT images of the USTUR case 0846 leg and detailed radiochemical analysis of small bone sections from the same leg. In-vivo measurements were performed on the USTUR case 0846 leg. Front and lateral measurements of the knee of the USTUR case 0846 leg in a bent position and the same measurements with the leg in a straight position using a HP(Ge) detector were obtained. The experimental measurements showed that the front measurement of the knee in a bent leg position gave the highest counts rate and therefore the highest detection efficiency. Therefore, this geometry and the knee-detector position may be considered as the most appropriate position for knee monitoring. A computational model using the Monte Carlo (MC) code, namely MCNPX was created to simulate the experimental measurements by utilizing a leg voxel phantom. It was observed that there is no difference at the 0.1 significance level between the simulated and measured detection efficiencies in the assessment of 241Am within the bones. After the MCNPX model was validated, different simulation scenarios were performed using the leg voxel phantom. Evidence of a significant difference (p

Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards

Arrangements for the Termination of a Nuclear Or Radiological Emergency

Provides guidance and recommendations on arrangements to be made at the preparedness stage, as part of overall emergency preparedness, for the termination of a nuclear or radiological emergency and the subsequent transition from the emergency exposure situation to either a planned exposure situation or an existing exposure situation.