Development of a transportable neutron activation analysis system to quantify manganese in bonein vivo: feasibility and methodology

Abstract

This study was conducted to investigate the methodology and feasibility of developing a transportable neutron activation analysis (NAA) system to quantify manganese (Mn) in bone using a portable deuterium–deuterium (DD) neutron generator as the neutron source. Since a DD neutron generator was not available in our laboratory, a deuterium–tritium (DT) neutron generator was used to obtain experimental data and validate the results from Monte Carlo (MC) simulations. After validation, MC simulations using a DD generator as the neutron source were then conducted. Different types of moderators and reflectors were simulated, and the optimal thicknesses for the moderator and reflector were determined. To estimate the detection limit (DL) of the system, and to observe the interference of the magnesium (Mg) γ line at 844 keV to the Mn γ line at 847 keV, three hand phantoms with Mn concentrations of 30 parts per million (ppm), 150 ppm, and 500 ppm were made and irradiated by the DT generator system. The Mn signals in these phantoms were then measured using a 50% high-efficiency high-purity germanium (HPGe) detector. The DL was calculated to be about 4.4 ppm for the chosen irradiation, decay, and measurement time. This was calculated to be equivalent to a DL of about 3.3 ppm for the DD generator system. To achieve this DL with one 50% high-efficiency HPGe detector, the dose to the hand was simulated to be about 37 mSv, with the total body equivalent dose being about 23μSv. In conclusion, it is feasible to develop a transportable NAA system to quantify Mn in bone in vivo with an acceptable radiation exposure to the subject.

Manganese accumulation in bone following chronic exposure in rats: Steady-state concentration and half-life in bone

“…Schroeder et al (1966) observed an average concentration of 2 mg/kg of Mn in bone ash, which gives rise to about 32.5% of body Mn in bone, according to our recent calculation (Liu et al, 2013). The International Commission on Radiological Protection (ICRP) has reported approximately 40% of body Mn accumulates in bone (ICRP, 1972).…”

“…Recent advances in neutron activation-based detection technology has made it possible to develop a transportable neutron activation analysis (NAA) system for quantifying MnBn (Liu et al, 2013). This highly innovative technique uses a portable deuterium–deuterium (DD) neutron generator (as the neutron source) to detect Mn in bone, non-invasively and in real time, in human subjects.…”

Manganese Toxicity Upon Overexposure: a Decade in Review

“…The equipment, at this writing, is compact enough to be transportable to the sites for testing human workers and subjects. The method is sensitive and can quantify Mn concentrations as low as 0.5 ppm of Mn in bone [14, 132] and recently even lower to 0.3 ppm (personal communication).…”

“…Whole blood Mn levels and the MRI signals in the globus pallidus were also reduced [57]. In vitro studies have documented that EDTA can effectively block toxic effects of Mn on mitochondrial oxygen consumption when added either before or after Mn exposure [132]. Thus, for the purpose of reducing Mn in the blood compartment in the initial emergency phase, EDTA has a therapeutic benefit.…”

A Dosimetry Study of Deuterium-Deuterium Neutron Generator-based In Vivo Neutron Activation Analysis

“…The NAA method is used at Purdue University to detect manganese in human hand bone in vivo and will eventually expand to detect other potentially toxic elements in bone (Liu et al 2013(Liu et al , 2014. The neutron and photon doses to the extremity (hand and arm) as well as to the whole body need to be determined for radiation exposure risk communication as well as Institutional Review Board (IRB) permission.…”