Shear modulus imaging by direct visualization of propagating shear waves with phase-sensitive optical coherence tomography

Song, Shaozhen; Huang, Zhihong; Nguyen, Thu-Mai; Wong, Emily Y.; Arnal, Bastien; O’Donnell, Matthew; Wang, Ke

doi:10.1117/1.jbo.18.12.121509

Cited by 89 publications

(90 citation statements)

References 42 publications

(45 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…General OCE techniques employ a loading device to induce tissue deformation and utilize OCT-based displacement-detection technique to monitor the dynamic response of the tissue [34][35][36]. The feasibilities of using OCE for three-dimensional elastic imaging [37,38], in vivo detection [39][40][41] and Young's modulus measurement [42][43][44] have been demonstrated on tissue-mimicking phantoms and different types of biological tissues, such as skin and soft-tissue tumor.…”

Section: Introductionmentioning

confidence: 99%

Noncontact depth-resolved micro-scale optical coherence elastography of the cornea

Wang

Larin

2014

Biomed. Opt. Express

151

125

View full text Add to dashboard Cite

High-resolution elastographic assessment of the cornea can greatly assist clinical diagnosis and treatment of various ocular diseases. Here, we report on the first noncontact depth-resolved micro-scale optical coherence elastography of the cornea achieved using shear wave imaging optical coherence tomography (SWI-OCT) combined with the spectral analysis of the corneal Lamb wave propagation. This imaging method relies on a focused air-puff device to load the cornea with highly-localized lowpressure short-duration air stream and applies phase-resolved OCT detection to capture the low-amplitude deformation with nano-scale sensitivity. The SWI-OCT system is used here to image the corneal Lamb wave propagation with the frame rate the same as the OCT A-line acquisition speed. Based on the spectral analysis of the corneal temporal deformation profiles, the phase velocity of the Lamb wave is obtained at different depths for the major frequency components, which shows the depthwise distribution of the corneal stiffness related to its structural features. Our pilot experiments on ex vivo rabbit eyes demonstrate the feasibility of this method in depth-resolved micro-scale elastography of the cornea. The assessment of the Lamb wave dispersion is also presented, suggesting the potential for the quantitative measurement of corneal viscoelasticity. 3026-3031 (2007). 3. L. T. Nordan, "Keratoconus: diagnosis and treatment," Int. Ophthalmol. Clin. 37(1), 51-63 (1997). 4. C. Edmund, "Corneal elasticity and ocular rigidity in normal and keratoconic eyes," Acta Ophthalmol. (Copenh.) 66(2), 134-140 (1988 Biol. 93(1-3), 176-191 (2007). 17. G. Scarcelli and S. H. Yun, "Confocal Brillouin microscopy for three-dimensional mechanical imaging," Nat. ©2014 Optical Society of AmericaPhotonics 2(1), 39-43 (2008). 18. J. Schmitt, "OCT elastography: imaging microscopic deformation and strain of tissue," Opt. Express 3(6), 199-211 (1998). 19. G. Scarcelli and S. H. Yun, "In vivo Brillouin optical microscopy of the human eye," Opt. Express 20(8), 9197-9202 (2012). 20. G. Scarcelli, R. Pineda, and S. H. Yun, "Brillouin optical microscopy for corneal biomechanics," Invest.Ophthalmol. Vis. Sci. 53(1), 185-190 (2012). 21. G. Scarcelli, S. Kling, E. Quijano, R. Pineda, S. Marcos, and S. H. Yun, "Brillouin microscopy of collagen crosslinking: noncontact depth-dependent analysis of corneal elastic modulus," Invest. Ophthalmol. Vis. Sci.

show abstract

Section: Introductionmentioning

confidence: 99%

Noncontact depth-resolved micro-scale optical coherence elastography of the cornea

Wang

Larin

2014

Biomed. Opt. Express

151

125

View full text Add to dashboard Cite

show abstract

“…The PhS-OCT system 16 was used to detect the generated mechanical wave from the opposite side of a phantom, mimicking the cornea, to avoid any artifacts related with the excitation itself. The sensitivity of the OCT system has been shown to be sufficient to detect ARF-based generated mechanical waves.…”

mentioning

confidence: 99%

“…A phase-sensitive (PhS)-OCT system 16 was used to detect the guided mechanical wave generated in the gelatin phantom from the opposite side of the phantom. The PhS-OCT system operated in M-mode at a 91.2 kHz A-scan rate, enabling mechanical wave tracking in time and space frame by frame, with a displacement sensitivity of 3 nm.…”

mentioning

confidence: 99%

“…US attenuation in air is about 2 dB/cm at 1 MHz, 14 quite reasonable for a few cm propagation path. A 91.2 kHz A-line rate optical coherence elastography (OCE) imaging system 16 was operated in M-B mode to image the induced mechanical waves, as discussed below. Thus, both mechanical wave generation and detection are non-contact, which enables remote and non-invasive characterization of soft tissue.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Air-coupled acoustic radiation force for non-contact generation of broadband mechanical waves in soft media

Ambroziński

Pelivanov

Song

et al. 2016

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

A non-contact method for efficient, non-invasive excitation of mechanical waves in soft media is proposed, in which we focus an ultrasound (US) signal through air onto the surface of a medium under study. The US wave reflected from the air/medium interface provides radiation force to the medium surface that launches a transient mechanical wave in the transverse (lateral) direction. The type of mechanical wave is determined by boundary conditions. To prove this concept, a homemade 1 MHz piezo-ceramic transducer with a matching layer to air sends a chirped US signal centered at 1 MHz to a 1.6 mm thick gelatin phantom mimicking soft biological tissue. A phasesensitive (PhS)-optical coherence tomography system is used to track/image the mechanical wave. The reconstructed transient displacement of the mechanical wave in space and time demonstrates highly efficient generation, thus offering great promise for non-contact, non-invasive characterization of soft media, in general, and for elasticity measurements in delicate soft tissues and organs in bio-medicine, in particular. Published by AIP Publishing. [http://dx.doi.org/10.1063/1.4959827] Acoustic radiation force (ARF) is commonly used in ultrasound (US)-based elastography to remotely generate shear waves deep within tissue. 1-3 Detection of shear waves can be performed with a conventional ultrasound (US) imaging probe or with another imaging method, e.g., optical coherence tomography (OCT). The combination of ARF with high frame rate OCT can produce quantitative crosssectional maps of the shear modulus in soft tissues. 4 For many clinical applications, however, a totally non-contact system for generation/detection of mechanical waves is desirable and, in some cases (for instance, the eye), is necessary. OCT is an ideal approach for these applications if an efficient and robust non-contact generation technology can be developed.Generation of mechanical waves with an air puff was used in Ref. 5 to produce very narrow bandwidth displacements in the cornea, which may not be able to characterize corneal elasticity at the spatial resolution required for clinical decision making. Our group has recently demonstrated non-contact generation using absorption of pulsed UV laser light. 6 Although UV generation can provide the bandwidth required for high spatial resolution maps of corneal elasticity, it is not clear at this point whether the required UV energy levels will meet the safety requirement for routine clinical use.Here we propose a fully non-contact and non-invasive US technique to create efficient localized wideband mechanical waves in soft tissue. The method utilizes US launched with an air-coupled transducer (i.e., through air) to the air/ medium interface. The US wave reflected from this interface provides radiation force to the medium surface, which induces a transient displacement at that surface, ultimately generating a propagating shear/guided/interface/Lamb wave (wave type determined by boundary conditions). We will call this the mechanical wave to maintain ge...

show abstract

“…Benefiting from the micrometer spatial resolution and millimeter penetration of optical coherence tomography (OCT), optical coherence elastography (OCE) based on the shear wave measurement has shown promising results in biomedical studies, including blood coagulation assessment, 8 ocular elasticity assessment, 4,9 and cardiac muscle measurement. 10 In an OCE application, an excitation from a force source, such as an ultrasonic transducer, 11-15 an airpuff device, 9 and a piezo-transducer (PZT), 16 is commonly applied to induce vibration, and OCT is used to detect the displacement and visualize the shear wave. Using shear wave elastography, the shear modulus is quantified by tracking the shear wave propagation.…”

mentioning

confidence: 99%

Longitudinal shear wave imaging for elasticity mapping using optical coherence elastography

Zhu

Miao

et al. 2017

Applied Physics Letters

View full text Add to dashboard Cite

Shear wave measurements for the determination of tissue elastic properties have been used in clinical diagnosis and soft tissue assessment. A shear wave propagates as a transverse wave where vibration is perpendicular to the wave propagation direction. Previous transverse shear wave measurements could detect the shear modulus in the lateral region of the force; however, they could not provide the elastic information in the axial region of the force. In this study, we report the imaging and quantification of longitudinal shear wave propagation using optical coherence tomography to measure the elastic properties along the force direction. The experimental validation and finite element simulations show that the longitudinal shear wave propagates along the vibration direction as a plane wave in the near field of a planar source. The wave velocity measurement can quantify the shear moduli in a homogeneous phantom and a side-by-side phantom. Combining the transverse shear wave and longitudinal shear wave measurements, this system has great potential to detect the directionally dependent elastic properties in tissues without a change in the force direction. Published by AIP Publishing. Elastography has provided a non-invasive imaging modality to assess the state of tissues and diseases by elastic properties of soft tissues since the mid-1990s. [1][2][3][4] The shear wave measurement is a quantitative method for the determination of elastic properties. For the shear wave measurement in elastography, a force source excites the tissue to induce a shear wave. The shear wave moves through the body of the tissue as a transverse wave where the vibration direction is perpendicular to the wave travel direction. An imaging system detects the vibration in the body to visualize the shear wave propagation. The shear modulus l can be quantitatively calculated from the shear wave velocity c by the following equation:where q is the tissue density. 5 Ultrasound imaging and magnetic resonance imaging have been used to image shear wave propagation in tissues. 6,7 However, the spatial resolutions of elastic maps are limited by the imaging technologies. Benefiting from the micrometer spatial resolution and millimeter penetration of optical coherence tomography (OCT), optical coherence elastography (OCE) based on the shear wave measurement has shown promising results in biomedical studies, including blood coagulation assessment, 8 ocular elasticity assessment, 4,9 and cardiac muscle measurement. 10 In an OCE application, an excitation from a force source, such as an ultrasonic transducer, 11-15 an airpuff device, 9 and a piezo-transducer (PZT), 16 is commonly applied to induce vibration, and OCT is used to detect the displacement and visualize the shear wave. Using shear wave elastography, the shear modulus is quantified by tracking the shear wave propagation. In previous measurements, the transverse shear wave propagates perpendicular to the force direction, so the shear modulus in the lateral region of the force can be quantified; 11-13 h...

show abstract

Shear modulus imaging by direct visualization of propagating shear waves with phase-sensitive optical coherence tomography

Cited by 89 publications

References 42 publications

Noncontact depth-resolved micro-scale optical coherence elastography of the cornea

Noncontact depth-resolved micro-scale optical coherence elastography of the cornea

Air-coupled acoustic radiation force for non-contact generation of broadband mechanical waves in soft media

Longitudinal shear wave imaging for elasticity mapping using optical coherence elastography

Contact Info

Product

Resources

About