Tracking mechanical wave propagation within tissue using phase-sensitive optical coherence tomography: motion...

Area of Science:

• Biomedical Optics
• Tissue Mechanics
• Medical Imaging

Background:

• Phase-sensitive optical coherence tomography (PS-OCT) is used to detect shear waves in tissues.
• Motion artifacts can compromise the accuracy of shear wave detection in PS-OCT.
• Understanding the sources of these artifacts is essential for reliable tissue characterization.

Purpose of the Study:

• To investigate the theoretical and experimental origins of motion artifacts in PS-OCT shear wave detection.
• To quantify the contribution of sample surface motion and refractive index differences to motion artifacts.
• To demonstrate a method for compensating motion artifacts and validate its effectiveness.

Main Methods:

• Theoretical modeling of shear wave propagation and artifact formation in PS-OCT.
• Experimental validation using tissue phantoms and biological tissues.
• Development and application of a surface motion compensation technique.

Main Results:

• Motion artifacts are a combined product of sample surface motion and refractive index mismatch between the sample and air.
• These artifacts significantly impact the estimation of intra-tissue motion.
• The proposed compensation method effectively reduces motion artifacts, improving measurement accuracy.

Conclusions:

• Surface motion and refractive index differences are critical factors causing artifacts in shear wave elastography.
• Accurate measurement of tissue mechanical properties necessitates compensation for surface motion.
• The demonstrated compensation method is vital for reliable elastography and other biomedical applications using PS-OCT.