Imaging flow dynamics in murine coronary arteries with spectral domain optical Doppler tomography

Area of Science:

• Cardiovascular Research
• Biomedical Optics
• Small Animal Imaging

Background:

• Assessing coronary artery blood flow is crucial for understanding cardiac function.
• In vivo imaging techniques are needed to visualize microvascular dynamics in small animals.
• Optical Doppler tomography offers potential for high-resolution assessment of blood flow.

Purpose of the Study:

• To evaluate spectral domain optical Doppler tomography (SD-ODT) for in vivo measurement of coronary blood flow in mice.
• To characterize blood flow dynamics in epicardial and intra-myocardial coronary arteries.
• To assess the feasibility of SD-ODT for structural and functional cardiac imaging.

Main Methods:

• In vivo blood flow measurement in murine coronary arteries using spectral domain optical Doppler tomography (SD-ODT).
• High frame rate video acquisition (up to 180 fps) to capture erythrocyte phase shifts.
• Image processing techniques including radial and temporal averaging (gating) for noise reduction and velocity measurement.
• 3D raster scans for vessel angle determination.

Main Results:

• SD-ODT successfully measured in vivo blood flow in murine coronary arteries.
• Peak instantaneous flow velocity in a ~40-µm vessel was 23.5 mm/s.
• Observed dynamic features included asymmetric vessel deformation and rapid flow reversal, confirming known coronary artery dynamics.
• Inter-subject variability in measurements was noted, attributed to physiological, anatomical, and instrumentation factors.

Conclusions:

• SD-ODT is a viable optical imaging tool for in vivo assessment of coronary blood flow in small animals.
• The technique provides structural and functional insights into cardiac hemodynamics.
• SD-ODT has potential applications in cardiovascular research and disease modeling.