Grating-based phase contrast tomosynthesis imaging: proof-of-concept experimental studies.

Area of Science:

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

Background:

• X-ray imaging is crucial in medical diagnostics.
• Conventional absorption contrast imaging has limitations in visualizing low-density materials.
• Phase contrast imaging techniques offer potential improvements.

Purpose of the Study:

• To evaluate the feasibility of x-ray differential phase contrast (DPC) tomosynthesis.
• To characterize the imaging performance of a grating-based DPC benchtop system.
• To assess the potential for improved visibility of low-density materials.

Main Methods:

• Utilized a grating-based DPC benchtop system with a digital flat-panel detector and rotating-anode x-ray tube.
• Acquired 21 projection views for tomosynthesis reconstruction.
• Reconstructed absorption contrast (AC-tomo), phase contrast (PC-tomo), and differential phase contrast (DPC-tomo) image volumes.
• Characterized signal linearity, SDNR, 3D NPS, and ASF using physical phantoms.

Main Results:

• DPC-tomo highlights edges and interfaces.
• PC-tomo pixel values correlate with the refractive index decrement.
• Signal difference-to-noise ratio (SDNR) improved in PC-tomo compared to AC-tomo.
• PC-tomo and AC-tomo showed equivalent artifact spread function (ASF) but different noise characteristics.

Conclusions:

• Simultaneous generation of DPC, PC, and AC tomosynthesis images is feasible with a grating-based setup.
• The method shows promise for enhancing the visibility of low-density materials.
• Further investigation is warranted for clinical applications.