4D x-ray phase contrast tomography for repeatable motion of biological samples

Area of Science:

• Biophysics
• Medical Imaging
• Materials Science

Background:

• X-ray phase contrast tomography (XPCT) offers high sensitivity for biological imaging.
• Dynamic measurements of biological samples require fast and efficient imaging techniques.

Purpose of the Study:

• To enhance XPCT for fast, dynamic measurements of biological samples.
• To develop a 4D imaging technique combining high-resolution 3D XPCT with time-resolved measurements.

Main Methods:

• Utilized a grating interferometer for XPCT with optimized scanning procedures.
• Employed a triangle-wave voltage signal for fast phase stepping and an optical fiber-coupled scientific CMOS camera for rapid image acquisition.
• Implemented a cooling system to maintain sample freshness during 4D scans.

Main Results:

• Achieved an 8-minute scan time with a density resolution of 2.4 mg/cm³ and a voxel size of 6.5 μm.
• Successfully performed 4D measurements, capturing time-resolved deformation of rat tendon fascicles under uniaxial stress at 5.7 Hz.
• Obtained quantitative data on fascicle cross-sectional area, length, and mass density during deformation.

Conclusions:

• The optimized XPCT method enables rapid, high-resolution 4D imaging of dynamic biological processes.
• This technique provides a powerful tool for quantitative analysis of soft tissue deformation and mechanical properties.
• The advancements facilitate in-situ studies of biological materials under physiological conditions.