A geometric-sensitivity-difference method improves object depth-localization for continuous-wave fluorescence diffuse...

Area of Science:

• Biomedical Optics
• Medical Imaging
• Fluorescence Imaging

Background:

• Accurate depth localization is crucial for quantitative analysis in fluorescence diffuse optical tomography (FDOT).
• Conventional FDOT methods often struggle with depth-dependent variations in measurement sensitivity.
• Existing reconstruction techniques may not fully compensate for the inherent sensitivity changes with object depth.

Purpose of the Study:

• To introduce and evaluate a novel geometric-sensitivity-difference (GSD) based reconstruction method for FDOT.
• To improve the depth-localization accuracy of objects in 2D continuous-wave FDOT.
• To compare the performance of the GSD method against conventional reconstruction techniques.

Main Methods:

• Developed a GSD method that optimizes data-model fit using paired source-detector measurements.
• Conducted an in silico study using a 2D circular-array outward-imaging geometry.
• Evaluated GSD against a baseline method and a depth-adapted weighted method using synthetic data with varying object contrasts and depths.

Main Results:

• The GSD method demonstrated superior performance in localizing single anomalies compared to conventional methods.
• GSD effectively resolved two closely spaced anomalies, outperforming baseline and depth-adapted weighted approaches.
• The method showed robust performance for both positive (3-fold) and negative (1/3-fold) fluorescence contrasts.

Conclusions:

• The geometric-sensitivity-difference (GSD) method significantly enhances depth localization in FDOT.
• GSD offers improved accuracy for both single and multiple object detection and resolution.
• This technique holds promise for applications like imaging prostate zinc-specific fluorophore uptake.