Digital image correlation–based optical coherence elastography

Abstract

Abstract. Optical coherence elastography (OCE) provides deformation or material properties, mapping of soft tissue. We aim to develop a robust speckle tracking OCE technique with improved resolution and accuracy. A digital image correlation (DIC)-based OCE technique was developed by combining an advanced DIC algorithm with optical coherence tomography (OCT). System calibration and measurement error evaluation demonstrated that this DIC-based OCE technique had a resolution of ∼0.6 μm displacement and <0.5% strain measurement in the axial scan direction. The measured displacement ranged from 0.6 to 150 μm, obtained via phantom imaging. The capability of the DIC-based OCE technique, for differentiation of stiffness, was evaluated by imaging a candle gel phantom with an irregularly shaped stiff inclusion. OCE imaging of a chicken breast sample differentiated the fat, membrane, and muscle layers. Strain elastograms of an aneurysm sample showed heterogeneity of the tissue and clear contrast between the adventitia and media. These promising results demonstrated the capability of the DIC-based OCE for the characterization of the various components of the tissue sample. Further improvement of the system will be conducted to make this OCE technique a practical tool for measuring and differentiating material properties of soft tissue.

Optical coherence elastography for measuring the deformation within glass fiber composite

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Two-dimensional micro-displacement measurement for laser coagulation using optical coherence tomography

“…Third, the correlation coefficient reduces with time due to general fluctuations, such as sample deformation [14]. This limits the measurable time separation between the reference and target B-scans.…”

“…Second, OCT visualizes a spatially-resolved structural change, which is necessary to observe localized tissue alteration. Third, OCT can directly monitor the thermal changes of the tissue including mechanical displacement, where such displacements can be measurable with the help of phase-sensitive measurements [9][10][11][12], speckle tracking [13], digital image correlation [14], and decorrelation [15,16]. Therefore, OCT is a promising tool for thermal expansion measurements.…”

Novel methods for elasticity characterization using optical coherence tomography: Brief review and future prospects

“…For this purpose, the elastography based on optical techniques such as optical coherence tomography (OCT) has been developed over the last 15 years, the seminal paper by Schmitt [4] being one of the first publications on this topic. In comparison with other elastographic techniques developed in medical ultrasound (US) or magnetic resonance imaging, the OCT-based elastography (optical coherence elastography, OCE) ensures significantly higher resolution, potentially enabling better localization and earlier detection of pathological regions [5][6][7][8][9][10][11][12][13][14][15][16][17].…”