Cortical blood flow assessment with frequency-domain laser Doppler microscopy

Area of Science:

• Biomedical optics
• Neuroimaging
• Physiology

Background:

• Cerebral blood flow (CBF) is a critical physiological parameter.
• Accurate and minimally invasive measurement techniques are essential for studying brain function and disease.
• Conventional laser Doppler methods have limitations in spatial coverage and invasiveness.

Purpose of the Study:

• To assess changes in cerebral blood flow (CBF) in vivo using a novel wide-field laser Doppler imager.
• To evaluate the performance of a CCD camera-based detection scheme for measuring Doppler shifts.
• To establish a minimally invasive method for monitoring dynamic CBF variations.

Main Methods:

• Development of a wide-field laser Doppler imager utilizing a CCD camera.
• Implementation of heterodyne optical detection with frequency domain analysis.
• Measurement of the quadratic mean of the frequency shift as an indicator of CBF.
• In vivo experiments in mice designed to induce controlled blood flow changes.

Main Results:

• The developed imager successfully acquired data under minimally invasive conditions.
• The frequency domain measurement of Doppler signatures provided an indicator of CBF.
• Significant variability in the CBF indicator was observed during induced blood flow changes.
• The system demonstrated potential for real-time monitoring of CBF dynamics.

Conclusions:

• The novel wide-field laser Doppler imager is a promising tool for assessing in vivo cerebral blood flow.
• The frequency domain approach offers advantages over conventional laser Doppler techniques.
• This method allows for minimally invasive monitoring of dynamic CBF changes in preclinical research.