Ultra-fast line-field low coherence holographic elastography using spatial phase shifting.

Area of Science:

• Biomedical Optics
• Biophysics
• Medical Imaging

Background:

• Optical coherence elastography (OCE) quantifies tissue biomechanics.
• Traditional OCE uses slow point-by-point scanning, limiting clinical use.
• Faster, noncontact methods are needed for real-time biomechanical assessment.

Purpose of the Study:

• To develop and validate a noncontact, single-shot optical coherence elastography system.
• To enable rapid acquisition of elastic wave propagation for mechanical property quantification.
• To assess the feasibility of this technique for *in situ* tissue analysis.

Main Methods:

• A noncontact single-shot line-field low coherence holography system was developed.
• Automatic Hilbert transform analysis based on spatial phase shifting was utilized.
• Spatio-temporal maps of elastic wave propagation were acquired using a single air-pulse excitation.
• Wave velocity and mechanical properties were quantified at a 200 kHz line rate.

Main Results:

• The system achieved a 200 kHz line rate for rapid data acquisition.
• Results from phantom studies correlated well with established mechanical testing.
• The stiffness of porcine cornea was successfully quantified *in situ* under varying intraocular pressures.

Conclusions:

• The developed system offers a significant speed improvement over conventional OCE.
• This noncontact, single-shot OCE technique is suitable for rapid biomechanical property quantification.
• The method shows promise for *in situ* *in vivo* clinical applications, particularly in ophthalmology.