Purpose: The purpose of this project is to alleviate the burden incurred by current radiation protection equipment on interventional radiology physicians and staff leading to orthopedic and musculoskeletal issues resulting in missed work days and shortened careers. This is being accomplished through the efficient use of advanced shielding materials combined with an ergonomic system which comfortably provides protection over the entire diagnostic range.
Material and methods: Energy absorption coefficients from National Institute of Standards and Technology (NIST) for all elements with Z > 45 were ranked for discrete energies incrementally ranging from 20 keV to 150 keV. Elements which are feasible for use with the highest absorption coefficients for specific energies over this range were compared to Lead (Pb) shielding at the specific x-ray energies corresponding to their superior absorption coefficients. Multiple homogenous distribution and layered configurations of including those elements were designed based on optimizing results for 150 kV quality, and MCNP (Monte Carlo N-Particle Transport Code) simulations were carried out to measure transmission compared to 0.5mm Pb and the current state of the art at 100 and 150 kV to identify configurations that had the greatest reduction in photon fluence and dose transmission compared to Pb on a per mass basis.
Secondly, a polymer sheet was configured in a hollow honeycomb core design filled with cell voids filled with radiation attenuating materials to calculate the mass savings achieved compared to conventional apron designs which have much higher proportions of polymer materials.
Results: Based on the absorption coefficients and MCNP results showing percent dose transmission, the greatest potential for improvement in protection over Pb near 80 keV, just below its K-edge. Especially near 80 keV, several elements included in our design offer more efficient protection compared to Pb.
Based on MCNP simulations, the layered geometry designs performed much better than 0.5 mm Pb, homogenous geometry and the current state of the art apron at both 100 kV and 150 kV.
Lastly, using a hollow honeycomb core filled with pure radiation attenuating material resulted in mass reduction of 31.7% while maintaining 0.5mm Pb equivalent protection.
Conclusion: We have identified new combinations of elements that can provide better protection compared to 0.5 mm Pb and the current state of the art solution. We are now working towards replicating our simulation results with experimental testing and incorporating the materials identified into a lightweight and ergonomic personal radiation shielding device for interventional staff.
