Computationally-efficient linear scheme for overlap time-gating spatial frequency domain diffuse optical tomography...

Area of Science:

• Biomedical Optics
• Medical Imaging
• Photonics

Background:

• Diffuse Optical Tomography (DOT) offers potential for laminar imaging of optical properties.
• Full time-resolved data in DOT enhances reconstruction but increases computational cost and limits signal-to-noise ratio (SNR).

Purpose of the Study:

• To develop a computationally efficient linear scheme for Time-Domain Spatial Frequency Domain Diffuse Optical Tomography (TD-SFD-DOT).
• To improve SNR and reduce data redundancy in DOT using overlap time-gating.
• To enable practical, high-resolution laminar tomography of absorption and scattering coefficients.

Main Methods:

• Derived an analytical solution to the Time-Domain (TD) phasor diffusion equation for semi-infinite geometry.
• Formulated Jacobian matrices using overlap time-gating data from time-resolved measurements.
• Developed a two-step linear inversion procedure based on algebraic reconstruction technique (ART) with memory-speed optimization and parallel computation.

Main Results:

• Validated the proposed TD-SFD-DOT method through simulations and phantom experiments.
• Achieved tomographic reconstruction with a relative depth resolution of approximately 4 mm.
• Demonstrated improved SNR and reduced data redundancy compared to conventional methods.

Conclusions:

• The proposed computationally-efficient linear TD-SFD-DOT method is effective for laminar tomography.
• The method enhances SNR and reduces redundancy, making it suitable for practical applications.
• Achieved depth resolution of ~4 mm shows promise for detailed subsurface imaging.