Program Information
Development of a Novel in Vivo Associated Particle Neutron Elemental Imaging System for Noninvasive Medical Diagnostics
M Abel*, H Nie , Purdue Univ, West Lafayette, IN
Presentations
WE-RAM1-GePD-I-5 (Wednesday, August 2, 2017) 9:30 AM - 10:00 AM Room: Imaging ePoster Lounge
Purpose: The purpose of this study is to develop a Monte Carlo simulation model for in vivo associated particle neutron elemental imaging (APNEI) and to study the feasibility of using APNEI to determine the iron distribution in a human liver. Because disease states cause elemental concentrations to differ from what is normal in a particular tissue, APNEI is a potential tool to be employed in disease diagnosis and treatment planning.
Methods: The model presented in this study was defined in the Los Alamos Monte Carlo Neutral Particle (MCNP) transport code by the geometry of the human body, the use of deuterium + deuterium source neutrons, an iron-containing voxel in the liver as the target region, and two high purity germanium (HPGe) detectors anterior and posterior to the trunk of the body. The pulse height and average flux tallies were employed in MCNP to determine the signal acquired from iron inelastic scatter gamma-rays as well as the equivalent dose to the liver and effective dose to the whole body. The dose estimates provided the basis for the collection of sufficient iron gamma-ray signals to construct a 2D image of iron distribution in the liver voxel.
Results: Assuming an allowable equivalent dose to the liver of 5 mSv, 143 inelastic scatter iron gamma-ray counts would be registered at the germanium detectors for a 1cm³ cube-shaped liver voxel with an iron concentration of 1,000 ppm. According to the simulation model, an image of iron distribution in the liver can be constructed with a 1 cm resolution at the level of 1,000 ppm iron. Collecting such an image would yield an estimated whole body dose of 0.82 mSv.
Conclusion: APNEI of certain elements in vivo appears feasible for application in disease diagnostics given several timing, sensitivity, and resolution caveats. Further study is ongoing.
Funding Support, Disclosures, and Conflict of Interest: This work was supported by the NRC Faculty Development Grant and the NRC Nuclear Engineering and Health Physics Fellowship Program at Purdue University. The authors have no relevant conflicts of interest to disclose.
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