Excitation spectroscopy in multispectral optical fluorescence tomography: methodology, feasibility and computer...

Area of Science:

• Biomedical Optics
• Medical Imaging
• Biophotonics

Background:

• In vivo optical fluorescence tomography (OFT) relies on probes emitting light in the 680-850 nm range for low tissue attenuation.
• Existing multispectral emission approaches offer limited improvement due to small spectral variations in tissue optical properties.
• Exploiting wavelength-dependent excitation properties offers an alternative for decoding source depth.

Purpose of the Study:

• To develop and evaluate a novel OFT method integrating both multi-wavelength excitation and multispectral emission data.
• To enhance the reconstruction accuracy of 3D fluorescent probe distributions in small animal studies.
• To assess the performance of this combined spectral approach against single-spectral methods.

Main Methods:

• Formulation of a linear algebraic forward model for multiple wavelength illumination and multispectral detection in OFT.
• Comparison of the combined spectral approach with excitation-only and emission-only spectral methods.
• Utilized a realistic inhomogeneous mouse atlas and singular value decomposition for analysis.

Main Results:

• The combined spectral approach demonstrates superior performance in OFT image reconstruction compared to single-spectral methods.
• Analysis using singular value decomposition highlights improved spatial resolution and noise characteristics.
• Successful 3D reconstruction of tumors in a simulated mouse model of metastatic human hepatocellular carcinoma was achieved.

Conclusions:

• Integrating both excitation and emission spectral information significantly enhances OFT's capability for deep-tissue imaging.
• This synergistic spectral approach offers a powerful tool for accurate 3D tumor visualization in preclinical research.
• The method shows promise for advancing in vivo molecular imaging and diagnostics.