PEPI Lab: a flexible compact multi-modal setup for X-ray phase-contrast and spectral imaging

Area of Science:

• Medical Imaging
• X-ray Imaging
• Phase-Contrast Imaging

Background:

• Conventional X-ray imaging relies on attenuation, limiting contrast for soft tissues.
• Edge-illumination (EI) techniques enhance contrast by detecting phase shifts.
• Multi-modal imaging offers comprehensive sample characterization.

Purpose of the Study:

• To present a novel, flexible, and compact multi-modal imaging system, the PEPI Lab.
• To enable simultaneous X-ray phase-contrast imaging (XPCI) and X-ray spectral imaging (XSI).
• To demonstrate the system's capabilities across various imaging modes and applications.

Main Methods:

• Development of a Photon-counting Edge-illumination Phase-contrast imaging (PEPI) Lab setup.
• Integration of a chromatic detector with EI technique for XPCI and XSI.
• Utilizing Geant4 simulations for system optimization and instrumentation selection.
• Operation in four modes: photon-counting/conventional, spectral, double-mask EI, and single-mask EI.

Main Results:

• The PEPI Lab system demonstrates flexibility and compactness with a 66 cm source-to-detector distance.
• High stability verified with mask misalignment below 1 µm over 54 hours.
• XSI imaging achieved quantitative results for iodine concentrations (mg/ml range).
• XPCI imaging showed high refraction sensitivity (<0.6 µrad) and a 15-fold SNR improvement in phase CT.

Conclusions:

• The PEPI Lab successfully integrates XPCI and XSI capabilities in a single, versatile system.
• The system's design and performance meet requirements for centimeter-scale imaging.
• Demonstrated potential for quantitative and sensitive imaging in diverse scientific and medical fields.