Real-time flow imaging by removing texture pattern artifacts in spectral-domain optical Doppler tomography

Area of Science:

• Biomedical Optics
• Medical Imaging
• Fluid Dynamics

Background:

• Optical heterogeneity in tissues causes texture pattern artifacts, degrading flow imaging performance.
• Real-time phase-resolved optical Doppler tomography (PRODT) is crucial for visualizing blood flow but is susceptible to these artifacts.
• Improving artifact suppression is key to enhancing the diagnostic capabilities of PRODT.

Purpose of the Study:

• To develop and validate a novel, simple method for suppressing texture pattern artifacts in optical Doppler tomography.
• To enhance the performance and accuracy of real-time flow imaging by mitigating artifacts from tissue optical heterogeneity.
• To enable clearer visualization of fluid dynamics in biological tissues.

Main Methods:

• A new method involving transverse scanning of the probe beam in forward and reverse directions was implemented.
• Spatial phase changes between successive axial scans were averaged to isolate true flow signals.
• The technique leverages the time-independent nature of phase changes due to optical heterogeneity versus time-dependent changes from moving particles.

Main Results:

• The proposed method effectively suppresses texture pattern artifacts caused by optical heterogeneity.
• Experimental demonstration using a flow phantom confirmed the successful real-time imaging of fluid flow.
• The averaged spatial phase changes accurately represented velocity information, improving image quality.

Conclusions:

• The developed transverse scanning method offers a simple and effective solution for artifact suppression in optical Doppler tomography.
• This technique significantly improves the performance of real-time flow imaging, particularly in optically heterogeneous samples.
• The findings pave the way for more reliable and precise non-invasive blood flow assessment using optical methods.