Gradient-based one-step fluorescence photoacoustic tomography.

Area of Science:

• Biomedical Optics
• Medical Imaging
• Computational Science

Background:

• Photoacoustic tomography (PAT) visualizes biological tissues using light and sound.
• Fluorescence PAT (FPAT) specifically targets exogenous fluorophores for imaging.
• Accurate reconstruction of absorption coefficients is crucial for FPAT applications.

Purpose of the Study:

• To develop and validate a novel gradient-based, one-step scheme for solving the FPAT inverse problem.
• To evaluate the computational efficiency and accuracy of the proposed scheme.
• To assess the robustness of the reconstruction method using different input data.

Main Methods:

• Adjoint-based gradient evaluation within a frequency-domain photoacoustic equation framework.
• Implementation of the Broyden-Fletcher-Goldfarb-Shanno (BFGS) optimization algorithm for reconstruction.
• Numerical validation in 2D with full and limited data, comparing against Jacobian-based methods.

Main Results:

• The proposed gradient-based FPAT scheme achieved comparable results to Jacobian-based methods.
• Significant computational savings were observed with the gradient-based approach.
• Reconstructions demonstrated robustness when using quantitative photoacoustic tomography (QPAT) data as input.

Conclusions:

• One-step gradient-based schemes present an advantageous and computationally efficient alternative for FPAT reconstructions.
• The method's robustness to QPAT-derived inputs enhances its potential clinical applicability.
• This work advances the field of quantitative fluorescence molecular imaging.