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Fluorescence Lifetime Macro Imager for Biomedical Applications
Published on: April 7, 2023
Tomographic imaging of oxygen by phosphorescence lifetime
Sovia V Apreleva1, David F Wilson, Sergei A Vinogradov
1Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA.
Applied Optics
|November 7, 2006
Summary
This study demonstrates 3D oxygen imaging using phosphorescence lifetime and diffuse optical tomography. This method enables visualization of oxygen concentrations within tissues, crucial for understanding physiological processes.
Area of Science:
- Biomedical Optics
- Medical Imaging
- Biophysics
Background:
- Oxygen concentration is a critical parameter in biological tissues.
- Accurate imaging of tissue oxygenation is essential for diagnosing and monitoring various physiological and pathological conditions.
- Current methods for 3D oxygen imaging have limitations in resolution and accessibility.
Purpose of the Study:
- To demonstrate the feasibility of three-dimensional (3D) oxygen imaging in tissues.
- To develop and validate a method combining phosphorescence quenching and diffuse optical tomography (DOT).
- To convert phosphorescence lifetime measurements into quantitative 3D oxygen concentration maps.
Main Methods:
- Utilized the phosphorescence quenching method with near-infrared phosphorescent probes.
- Employed diffuse optical tomography (DOT) to reconstruct images from boundary measurements.
- Applied time-domain phosphorescence measurements and exponential fitting to determine phosphorescence lifetime.
- Modeled light transport using the diffusion equation and finite element method.
- Solved the inverse problem using the recursive maximum entropy method.
Main Results:
- Successfully achieved tomographic imaging of oxygen concentration in three dimensions.
- Demonstrated the conversion of phosphorescence lifetime images into 3D oxygen concentration maps.
- Validated the method using hypoxic phantoms immersed in a scattering medium.
- Optimized excitation pulse duration to enhance image contrast.
Conclusions:
- Established the first example of 3D oxygen imaging using long-lived phosphorescent probes.
- Confirmed the potential of phosphorescence lifetime-based DOT for quantitative 3D oxygen imaging.
- This technique offers a promising non-invasive approach for assessing tissue oxygenation.
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