Improvement of transcutaneous fluorescent images with a depth-dependent point-spread function

Area of Science:

• Biomedical Optics
• Medical Imaging
• Fluorescence Imaging

Background:

• Transcutaneous fluorescent imaging is crucial for visualizing subsurface biological structures.
• Image quality is often degraded by scattering and absorption in biological tissues.
• Accurate characterization of light propagation is essential for improving image resolution and depth penetration.

Purpose of the Study:

• To develop and validate a depth-dependent point-spread function (PSF) for homogeneous turbid media.
• To improve the contrast and visible depth of transcutaneous fluorescent images.
• To demonstrate the practical application of the technique in biological imaging.

Main Methods:

• Derived an analytical closed-form solution for the PSF in homogeneous turbid media.
• Implemented a novel technique utilizing depth-dependent PSF to process transcutaneous fluorescent images.
• Quantified image contrast improvement at various depths (1-15 mm) in a scattering medium.
• Validated the method through an in vivo experiment on a rat model.

Main Results:

• The depth-dependent PSF technique significantly enhanced image contrast for depths up to 15 mm.
• The effective visible depth of imaging was more than doubled compared to conventional methods.
• In vivo imaging of a rat's cerebral vein showed considerable improvement in clarity and localization.
• The spatial spread of the heart's fluorescent image was accurately corrected using the depth-dependent PSF.

Conclusions:

• The developed depth-dependent PSF provides an effective analytical solution for improving transcutaneous fluorescent imaging.
• This technique offers a substantial advancement in visualizing deep fluorescent signals in scattering biological tissues.
• The method has demonstrated practical utility and significant potential for preclinical and clinical applications in medical diagnostics.