Visualization of microvessels by angiography using inverse-Compton scattering X-rays in animal models

Area of Science:

• Medical Imaging
• X-ray Technology
• Vascular Imaging

Background:

• Microangiography requires high resolution and small focal spots.
• Inverse-Compton scattering X-ray (iCSX) offers quasi-monochromatic X-rays and small focus size, ideal for microangiography.
• Current iCSX flux is insufficient for clinical microangiography.

Purpose of the Study:

• Evaluate the performance of S-band linac-based iCSX for microangiography.
• Determine the photon flux required for human microangiography.
• Assess the visualization capability of iCSX for small vessels in excised organs.

Main Methods:

• Utilized an S-band linac-based inverse-Compton scattering X-ray (iCSX) source.
• Employed a high-gain avalanche rushing amorphous photoconductor camera for initial resolution tests.
• Used an X-ray cooled charge-coupled device image sensor camera for imaging rabbit ear vasculature.
• Estimated required photon flux for clinical applications.

Main Results:

• A single iCSX pulse visualized a resolution chart with ~500 µm resolution.
• Seventh-order vascular branches (~80 µm diameter) in a rabbit ear were visualized by accumulating 3000-18000 iCSX pulses.
• iCSX successfully visualized microvessels through image accumulation.

Conclusions:

• S-band linac-based iCSX can visualize microvessels, particularly with image accumulation.
• A 3.6 × 10^3 to 5.4 × 10^4 times greater photon flux may enable real-time human microangiography, e.g., of fingertips.
• Further development of iCSX sources is needed to meet clinical demands for microangiography.