High-spatial-resolution x-ray fluorescence tomography with spectrally matched nanoparticles

Area of Science:

• Biomedical Imaging
• Nanotechnology
• Medical Physics

Background:

• Current imaging methods offer either high-resolution morphology (CT) or lower-resolution functional/molecular data (PET).
• X-ray fluorescence (XRF) imaging with nanoparticles shows promise for molecular imaging but has been limited by low sensitivity and spatial resolution.

Purpose of the Study:

• To develop a high-sensitivity, high-resolution X-ray fluorescence tomography method for in vivo molecular imaging.
• To demonstrate the feasibility of using metal-core nanoparticles for functional/molecular imaging in living subjects.

Main Methods:

• Laboratory X-ray fluorescence tomography utilizing a high-brightness liquid-metal-jet x-ray source.
• Employing pencil-beam optics, photon-counting energy-dispersive detection, and spectrally matched metal-core nanoparticles (NPs).
• Demonstrated 3D tumor imaging in mice using passively targeted molybdenum NPs.

Main Results:

• Achieved ~100 µm spatial resolution for functional/molecular imaging in living rodents.
• The novel XRF tomography method significantly enhances sensitivity compared to previous techniques.
• Demonstrated successful 3D tumor imaging in mice with acceptable exposure times and nanoparticle/radiation doses.

Conclusions:

• Laboratory X-ray fluorescence tomography with metal-core nanoparticles offers a viable path to high-resolution molecular imaging in biomedical research.
• This technique overcomes prior sensitivity limitations, enabling detailed functional and molecular visualization in vivo.
• The method holds potential for advancing preclinical research and diagnostic imaging applications.