Focused anti-scatter grid for background reduction in x-ray fluorescence tomography

Abstract

X-ray fluorescence (XRF) tomography is an emerging imaging technology with the potential for high spatial resolution molecular imaging. One of the key limitations is the background noise due to Compton scattering since it degrades the signal and limits the sensitivity. In this Letter, we present a linear focused anti-scatter grid that reduces the Compton scattering background. An anti-scatter grid was manufactured and evaluated both experimentally and theoretically with Monte Carlo simulations. The measurements showed a 31% increase in signal-to-background ratio, and simulations of an improved grid showed that this can easily be extended up to >75%. Simulated tomographies using the improved grid show a large improvement in reconstruction quality. The anti-scatter grid will be important for in vivo XRF tomography since the background reduction allows for faster scan times, lower doses, and lower nanoparticle concentrations.

Quantitative predictions in small-animal X-ray fluorescence tomography

“…It is capable of simulating practically any voxelized object and data acquisition geometry, with fully customizable source and detector configurations. An early version [20] was used to study different anti-scatter grid solutions for XRF tomography [21].…”

Formation and extreme thickness controlling mechanism of ultra-thin-wall tungsten grids fabricated via selective laser melting

“…Tungsten exhibits exceptional resistance to the sputtering of high-energy particles, low tritium retention, and remarkable shielding and absorption capabilities for high-energy radiation [1][2][3]. It has been extensively employed in anti-scatter grids (ASGs), a critical component of computed tomography (CT) equipment [4,5]. An ASG consists of thin-walled horizontal and longitudinal connections that form a grid structure with 1 mm square apertures on the flat surface and long vertical penetration lengths [6].…”