First point-spread function and x-ray phase-contrast imaging results with an 88-mm diameter single crystal

First point-spread function and x-ray phase-contrast imaging results with an 88-mm diameter single crystal

Citation

Lumpkin, A. H., Garson, A. B., & Anastasio, M. A. (2018). First point-spread function and x-ray phase-contrast imaging results with an 88-mm diameter single crystal. Review of Scientific Instruments, 89(7), 073704. https://doi.org/10.1063/1.5027499 

Keywords

  • X-ray phase-contrast (XPC) imaging
  • Propagation-based (PB) imaging
  • Single crystal scintillators
  • Point-spread function (PSF)
  • Fiber optic plate (FOP)
  • Spatial resolution
  • Detector efficiency
  • Light scattering 

Brief

The study presents the first application of an 88-mm diameter single crystal scintillator for indirect x-ray imaging and demonstrates its use for high-resolution propagation-based x-ray phase-contrast imaging. 

Summary

This article presents a novel approach to enhance the resolution of x-ray imaging, particularly in applications like phase-contrast imaging, by utilizing single-crystal scintillators instead of traditional polycrystalline phosphors. The authors conducted experiments comparing the performance of single-crystal YAG:Ce and LuAG:Ce scintillators to a standard P43 polycrystalline phosphor.

Here are the key findings from the article:

  • Superior Resolution with Single Crystals: The system achieved a four-fold improvement in spatial resolution (point-spread function, PSF) using 50-µm thick single crystals compared to the P43 phosphor. This improvement is attributed to reduced light scattering in single crystals.
  • Trade-off Between Efficiency and Resolution: While thinner scintillators provide better resolution, they also result in lower detection efficiency. The study explores this trade-off by examining the impact of crystal thickness and reflective coatings on both resolution and efficiency.
  • Impact of Fiber Optic Plate Depth of Focus: The study highlights the influence of the fiber optic plate's (FOP) depth of focus on the overall system resolution, especially with thicker scintillators.
  • Detrimental Effects of Reflective Coatings: While aluminum coatings on the scintillator's surface are commonly used to enhance light collection efficiency, the study reveals that this can negatively impact resolution due to increased light scattering.
  • Successful Implementation in Phase-Contrast Imaging: An 88-mm diameter YAG:Ce single crystal was integrated into a large-format camera and effectively demonstrated for phase-contrast imaging, producing sharper images compared to conventional absorption-based x-ray imaging.

The authors conclude that single-crystal scintillators, particularly the larger diameter versions, hold significant potential for enhancing various x-ray imaging applications requiring high resolution, such as phase-contrast imaging, crystal diffraction studies, and wafer topography analysis.

Origin: https://pubs.aip.org/aip/rsi/article/89/7/073704/358419

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