Ultra-wideband optical coherence elastography from acoustic to ultrasonic frequencies

Abstract

Visualizing viscoelastic waves in materials and tissues through noninvasive imaging is valuable for analyzing their mechanical properties and detecting internal anomalies. However, traditional elastography techniques have been limited by a maximum wave frequency below 1-10 kHz, which hampers temporal and spatial resolution. Here, we introduce an optical coherence elastography technique that overcomes the limitation by extending the frequency range to MHz. Our system can measure the stiffness of hard materials including bones and extract viscoelastic shear moduli for polymers and hydrogels in conventionally inaccessible ranges between 100 Hz and 1 MHz. The dispersion of Rayleigh surface waves across the ultrawide band allowed us to profile depth-dependent shear modulus in cartilages ex vivo and human skin in vivo with sub-mm anatomical resolution. This technique holds immense potential as a noninvasive measurement tool for material sciences, tissue engineering, and medical diagnostics.

High-Frequency Optical Coherence Elastography for Gingival Tissue Characterization: Variability in Stiffness and Response to Physiological Conditions

“…OCE’s potential is vast, with room for further refinement to enhance accuracy and clinical applicability. Expanding the frequency range beyond 16 kHz could improve resolution and enable the determination of layer-specific mechanical properties [ 23 , 36 ]. Designing smaller probes could allow access to deeper oral regions and a broader spectrum of tissues.…”