Dose fractionation in synchrotron radiation x-ray phase micro-tomography

Area of Science:

• Medical Imaging
• Materials Science
• Physics

Background:

• Phase-sensitive X-ray imaging offers higher sensitivity than traditional attenuation-based methods.
• X-ray phase is indirectly measured using phase contrast techniques and reconstructed from phase contrast images.
• Synchrotron X-ray phase micro-computed tomography (μCT) is crucial for imaging heterogeneous, strongly absorbing objects.

Purpose of the Study:

• To investigate the impact of dose fractionation on reconstructed image quality in multi-distance phase μCT.
• To compare different acquisition schemes, varying detector distances and exposure time fractions.
• To evaluate dose-fractionated multi-distance phase μCT against single-distance phase μCT.

Main Methods:

• Utilized synchrotron X-ray phase micro-computed tomography (μCT) with free-space propagation.
• Defined and tested novel acquisition schemes with variable sample-to-detector distances and exposure time distributions.
• Employed the mixed approach algorithm for phase retrieval and compared reconstructed images based on accuracy, precision, and resolution.

Main Results:

• Varying exposure times at each distance in multi-distance phase μCT demonstrably improved reconstructed image quality.
• The multi-distance method yielded superior image quality compared to single-distance μCT, even at equivalent total radiation doses.
• Optimizing acquisition parameters (number of distances, exposure time per distance) enhances image quality, potentially reducing required radiation dose.

Conclusions:

• Dose fractionation strategies in multi-distance phase μCT are effective in improving image quality for heterogeneous objects.
• Multi-distance phase μCT offers advantages over single-distance methods regarding image quality for a given total radiation dose.
• An optimized protocol for multi-distance phase μCT acquisition can be defined to achieve desired image quality with minimized radiation exposure.