Spectrally resolving and scattering-compensated x-ray luminescence/fluorescence computed tomography

Area of Science:

• Biomedical Imaging
• Medical Physics
• Nanotechnology

Background:

• Nanophosphors emit near-infrared (NIR) light under X-ray excitation, serving as optical probes for in vivo molecular and cellular imaging.
• Previous X-ray Fluorescence Computed Tomography (XFCT) and X-ray Luminescence Computed Tomography (XLCT) methods have limitations in quantifying nanophosphor distribution.
• Accurate quantification of nanophosphor distribution is crucial for in vivo visualization of biological targets and pathways.

Purpose of the Study:

• To develop a spectrally-resolving and scattering-compensated X-ray luminescence/fluorescence computed tomography (SXLCT/SXFCT) approach.
• To accurately quantify the spatial distribution of nanophosphors within biological objects.
• To address the challenges posed by X-ray scattering in quantitative imaging.

Main Methods:

• Incorporating X-ray scattering compensation into the reconstruction algorithm using a diffusion approximation model for NIR scattering.
• Utilizing spectrally-resolved X-ray excitations and NIR signal measurements.
• Establishing a linear relationship between nanophosphor distribution and measured NIR data via the finite element method.
• Inverting the data using compressive sensing techniques for quantitative reconstruction.

Main Results:

• Numerical simulations demonstrated the feasibility of the proposed SXLCT/SXFCT approach.
• The method effectively accounts for X-ray scattering effects in quantitative imaging.
• Accurate quantification of nanophosphor spatial distribution was achieved in simulations.

Conclusions:

• The developed SXLCT/SXFCT method offers a promising advancement for quantitative in vivo imaging.
• This technique can improve the visualization and analysis of molecular and cellular targets.
• The scattering compensation and spectral resolution enhance the accuracy of nanophosphor distribution quantification.