Phase contrast reflectance confocal brain imaging at 1650 nm.

Area of Science:

• Neuroscience
• Optical Microscopy
• Biomedical Imaging

Background:

• Microscopy imaging depth is limited by light penetration in biological tissues.
• Near-infrared II (NIR-II) spectrum combined with reflectance confocal microscopy offers increased imaging depth.
• Existing NIR-II systems require optical and post-processing improvements for cellular differentiation.

Purpose of the Study:

• To implement a phase contrast detection scheme in a NIR-II reflectance confocal microscope.
• To enhance the differentiation of cortical cells and small blood vessels.
• To develop methods for dynamic signal acquisition and vascular mapping.

Main Methods:

• Integration of a phase contrast detection scheme into a reflectance confocal microscope.
• Utilizing the NIR-II spectral range for illumination.
• Development of an acquisition method for distinguishing dynamic signals from background noise.

Main Results:

• Successful implementation of phase contrast for deep cortical imaging up to [specific depth] using a cranial window.
• Generation of vascular maps at similar depths, comparable to optical coherence tomography.
• Demonstration of combining multiple images to create comprehensive vessel networks.

Conclusions:

• Phase contrast reflectance confocal microscopy improves the visualization of cortical cell bodies.
• The presented framework enables the retrieval of angiograms from dynamic biological signals.
• This work refines a previous microscope design with novel optical implementation and analysis techniques.