Recent developments in quantitative phase-contrast microtomography using Talbot Array Illuminators

Abstract

This study explores recent developments in quantitative phase-contrast microtomography using Talbot Array Illuminators (TAI) combined with Unified Modulated Pattern Analysis (UMPA). We first compare the performance of the TAI-based method for phase-retrieval with propagation-based imaging (PBI) for analyzing a Mg-10Gd bone implant sample that violates the single-material assumption. Our results demonstrate that the TAI method yields a significantly higher contrast-to-noise ratio (CNR) compared to PBI (101.68 vs. 54.37, an 87% improvement) while maintaining comparable edge sharpness. The TAI method also visualizes a substructure of the degradation layer, which appears comparatively blurred in the PBI images. Additionally, we introduce a hanging-rotation-axis approach for imaging paraffin-embedded samples in an ethanol bath, aiming to reduce edge enhancement artifacts caused by large electron density differences. Preliminary results indicate that the TAI-based images of a paraffin-embedded lymph node show improved uniformity in background intensity, though some additional low-frequency noise is observed. All experiments were conducted at the High Energy Materials Beamline (HEMS), PETRA III, DESY, operated by Hereon. Our findings highlight the potential of TAI-based phase-contrast imaging for complex, multi-material samples and suggest avenues for further optimization of the technique.