Cycloidal-spiral sampling for three-modal x-ray CT flyscans with two-dimensional phase sensitivity.

Area of Science:

• Physics
• Materials Science
• Medical Imaging

Background:

• Traditional X-Ray Computed Tomography (CT) methods require sample stepping, increasing scan times.
• Multi-modal X-Ray CT with 2D phase sensitivity offers complementary contrast channels but faces acquisition challenges.
• Step-and-shoot implementations in CT are limited by motor overheads and prolonged scanning durations.

Purpose of the Study:

• To introduce a flyscan-compatible acquisition scheme for three-modal X-Ray CT.
• To enable simultaneous measurement of attenuation, phase, and scattering properties from a single frame.
• To reduce total scan time without compromising image quality or isotropic resolution.

Main Methods:

• A novel acquisition scheme integrating continuous horizontal and vertical sample translations with rotation, creating a "cycloidal-spiral" trajectory.
• Demonstration using a "beam tracking" setup for simultaneous data acquisition.
• Implementation of continuous scanning (flyscans) instead of traditional step-and-shoot methods.

Main Results:

• The proposed scheme is fully compatible with continuous flyscan acquisition.
• Greatly reduced scan times were achieved compared to step-and-shoot methods.
• High image quality and isotropic resolution were largely preserved.

Conclusions:

• The cycloidal-spiral trajectory enables efficient, high-quality multi-modal X-Ray CT.
• This method significantly accelerates the acquisition process for phase-sensitive X-Ray CT.
• The approach offers a promising advancement for applications requiring rapid, detailed sample characterization.