Optical coherence Doppler tomography for quantitative cerebral blood flow imaging

Area of Science:

• Neuroimaging
• Biomedical Optics
• Cerebrovascular Physiology

Background:

• Optical coherence Doppler tomography (ODT) offers 3D cerebral blood flow (CBF) imaging.
• Quantitative CBF velocity (CBFv) measurement using ODT is challenging, especially for slow capillary flows.

Purpose of the Study:

• To develop a novel method for enhancing sensitivity and accuracy in quantitative CBFv imaging with ODT.
• To improve the detection of slow capillary blood flow and enable precise angle correction for absolute CBFv quantification.

Main Methods:

• Implementation of a simple phase summation method to boost sensitivity for slow capillary flow detection.
• Integration of vessel tracking for improved angle correction to achieve absolute CBFv quantification.
• Validation using flow phantoms and in vivo mouse brain models.

Main Results:

• Flow phantom validation showed a significant increase in CBFv quantification accuracy from 15% to 91% and a 9.3-fold decrease in the coefficient of variation (CV).
• In vivo mouse brain studies demonstrated a 4.4-fold and 10.8-fold CV reduction for venular and arteriolar flows, respectively.
• The enhanced ODT method successfully identified cocaine-induced microischemia and quantified CBFv disruption in microvasculature.

Conclusions:

• The phase summation method substantially improves quantitative CBFv measurement accuracy and sensitivity in ODT.
• This technique enables detailed analysis of microvascular blood flow dynamics and pathological changes, such as microischemia.
• ODT with the enhanced method is a powerful tool for cerebrovascular research and clinical diagnostics.