Volumetric Doppler angle correction for ultrahigh-resolution optical coherence Doppler tomography

Area of Science:

• Biomedical optics
• Medical imaging
• Fluid dynamics

Background:

• Ultrahigh-resolution optical coherence Doppler tomography (μODT) offers large field of view and capillary resolution for quantitative blood flow imaging.
• Current μODT methods are limited to axial flow velocity detection and require Doppler angle correction for absolute velocity retrieval.
• Existing Doppler angle tracking methods are insufficient for complex, entire 3D microvascular networks.

Purpose of the Study:

• To develop and validate a novel method for accurate 3D Doppler angle correction in microvascular networks.
• To enable quantitative absolute blood flow velocity mapping in complex 3D vascular structures.
• To overcome the limitations of existing μODT techniques for comprehensive microvascular analysis.

Main Methods:

• A voxel-based method utilizing eigenvalue analysis of the 3D Hessian matrix to determine vessel orientation.
• Application of the method for tracking the Doppler angle matrix across entire 3D vascular networks.
• Validation using simulation, flow phantom studies, and in vivo mouse cerebral blood flow (CBF) imaging.

Main Results:

• The proposed method accurately retrieves vessel orientation for voxel-based Doppler angle tracking.
• Successful correction of Doppler angles and restoration of absolute flow in simulated and phantom 3D vascular networks.
• Demonstrated capability for tracking Doppler angles in highly complex in vivo mouse 3D CBF networks.

Conclusions:

• The eigenvalue-based Hessian matrix analysis provides an effective solution for 3D Doppler angle correction in μODT.
• This method enables accurate quantitative blood flow imaging in complex 3D microvascular networks.
• The technique significantly advances the potential of μODT for detailed microcirculation studies.