Large field-of-view tiled grating structures for X-ray phase-contrast imaging

Area of Science:

• Medical imaging
• Materials analysis
• X-ray grating interferometry

Background:

• X-ray grating-based interferometry offers novel diagnostic capabilities.
• Current limitations in field of view (FoV) hinder clinical radiography applications.
• Manufacturing complexities restrict the size of individual grating areas.

Purpose of the Study:

• To investigate the precision requirements for tiling grating tiles to create larger areas.
• To develop a method for extending the FoV in X-ray grating interferometry for clinical use.

Main Methods:

• Theoretical investigation using a simulation approach to determine accuracy needs for tiling.
• Development of a custom-built frame for precise positioning of grating tiles.
• Alignment verification by analyzing fringe patterns of adjacent grating tiles within an interferometer.

Main Results:

• Simulation results define the necessary precision for tiling in all degrees of freedom.
• A custom frame successfully achieves precise alignment of grating tiles.
• Demonstrated extension of FoV to a practical size (384 mm × 24 mm) in a phase-contrast scanning setup.

Conclusions:

• Tiling individual grating tiles is a viable method to overcome FoV limitations.
• Precise alignment, facilitated by the developed method, is crucial for successful FoV extension.
• The approach shows suitability for clinical radiography and materials analysis applications.