Complete angle small animal fluorescence imaging with early-arriving photons

Area of Science:

• Biomedical optics
• Molecular imaging
• Medical physics

Background:

• Fluorescence tomography is a powerful tool for quantitative, 3D imaging of optical reporter probes in vivo.
• Image quality in fluorescence tomography is significantly limited by light scatter within biological tissues.
• Time-gated detection of early-arriving photons offers a strategy to mitigate scatter effects.

Purpose of the Study:

• To investigate the utility of time-gated detection for improving fluorescence tomography in small animals.
• To assess the impact of early-arriving versus later-arriving photons on image quality.
• To demonstrate high-fidelity image reconstruction using this technique.

Main Methods:

• Full-angle tomographic imaging was performed on mice bearing fluorescent tubes.
• A femtosecond laser and a high-speed, time-gated intensified CCD imager were employed.
• Detection focused on early-arriving and later-arriving photons transmitted through tissue.

Main Results:

• Early-transmitted fluorescent photons significantly improved the visualization of fluorescence distribution, even in individual projections.
• High-fidelity, quantitative 3D image reconstruction was achieved using 72 projections with early-arriving photons.
• The technique demonstrated enhanced performance in minimizing scatter effects.

Conclusions:

• Time-gated detection of early-arriving photons is effective in improving image quality for fluorescence tomography.
• This approach enhances the visualization of optical reporter probes in whole animals.
• The method shows promise for advancing molecular imaging applications in preclinical research.