Quantitative Assessment of Hyaline Cartilage Elasticity during
Optical Clearing using Optical Coherence Elastography
Quantitative Assessment of Hyaline Cartilage Elasticity during
Optical Clearing using Optical Coherence Elastography
Chih-Hao Liu1, Manmohan Singh1, Jiasong Li1, Zhaolong Han1, Chen
Wu1, Shang Wang2, Rita Idugboe1, Raksha Raghunathan1, Valery P.
Zakharov3, Emil N. Sobol4, Valery V. Tuchin3,5,6, Michael Twa7, and
Kirill V. Larin1,3,5,6+
1Department of Biomedical Engineering, University of Houston,
3605 Cullen Boulevard, Houston, Texas 77204 USA2Department of
Molecular Physiology and Biophysics, Baylor College of Medicine,
One Baylor Plaza, Houston, Texas, 77030 USA3Department of
Electrical Engineering, Samara State Aerospace University, Samara,
443086 Russia4Department of Physics, Moscow State University,
Moscow, 119991 Russia 5Department of Optics and Biophotonics,
Saratov State University, Saratov, 410012 Russia6Interdisciplinary
Laboratory of Biophotonics, Tomsk State University, Tomsk 634050
Russia7College of Optometry, University of Houston, 505 J.Davis
Armistead Bldg., Texas 77204 USA
+ Corresponding author: [email protected]
Motivation
[1] M. G. Stewart, T. L. Smith, E. M. Weaver et al., Outcomes
after nasal septoplasty: results from the Nasal Obstruction
Septoplasty Effectiveness (NOSE) study, Otolaryngology--Head and
Neck Surgery, 130(3), 283-290 (2004).[2] E. Sobol, A. Sviridov, V.
Svistushkin et al., "Feedback controlled laser system for safe and
efficient reshaping of nasal cartilage." 7548, 75482H-75482H-5.[3]
E. Sobol, A. Sviridov, A. Omelchenko et al., Laser reshaping of
cartilage, Biotechnology and Genetic Engineering Reviews, 17(1),
553-578 (2000).[4] D. E. Protsenko, A. Zemek, and B. J. F. Wong,
Temperature dependent change in equilibrium elastic modulus after
thermally induced stress relaxation in porcine septal cartilage,
Lasers in Surgery and Medicine, 40(3), 202-210 (2008).
Laser septochondrcorrection (LSC)(non-destructive
surgery)advantageSafe(bloodless, painless) non-invasive Less
complication compared with traditional septoplasty surgery
[1,2]Stress relaxation process Permanent deformation Change from
Bound water to free water state Biomechanical property changes
[3]
Fig: Scheme of Laser septochondrcorrection procedureFig: Optimal
condition for laser reshaping window [3]Fig: Stress relaxation
mechanism [4]
MotivationOptical clearing techniqueAn approach to monitor the
change of tissue optical properties (structural information) OCT
signal slope [1]HoweverThe elasticity changes of biological tissues
during clearing process havent been studied yetOptical coherence
elastography (OCE)Biomechanical property measurementCornea[2],
soft-tissue tumor[3], cardiac muscle[4]In this workwe report the
first use of OCE to monitor the elasticity changes during optical
clearing process.Speckle variance analysis OCE detectionUniaxial
mechanical testing
Fig. Visualization of the elastic wave propagation in ex vivo
rabbit cornea[1] K. V. Larin, M. G. Ghosn, A. N. Bashkatov et al.,
Optical clearing for OCT image enhancement and in-depth monitoring
of molecular diffusion, IEEE Journal of Selected Topics in Quantum
Electronics, 18(3), 1244-1259 (2012).[2] S. Wang, and K. V. Larin,
Shear wave imaging optical coherence tomography (SWI-OCT) for
ocular tissue biomechanics, Optics letters, 39(1), 41-44 (2014).[3]
S. Wang, J. Li, R. K. Manapuram et al., Noncontact measurement of
elasticity for the detection of soft-tissue tumors using
phase-sensitive optical coherence tomography combined with a
focused air-puff system, Optics letters, 37(24), 5184-5186
(2012).[4] S. Wang, A. L. Lopez, Y. Morikawa et al., Noncontact
quantitative biomechanical characterization of cardiac muscle using
shear wave imaging optical coherence tomography, Biomedical Optics
Express, 5(7), 1980-1992 (2014).
Material and methodSample preparation Two samples were
width-wise extracted from the same nasal septum cartilageOCE
measurementUniaxial mechanical testingOptical clearing agent1X
PBS20% glucoseClearing period0-20 min: 1X PBS 21-140 min: 20%
glucose
1.3cm1cmFig: The used cartilages during the optical clear
experiment
Phase-stabilized swept source OCT (PhS-SSOCT) Broad band swept
laser:1310nmScan range: 150nmScan rate: 30k HzThe axial resolution:
~11 mPhase stability: 16 mScan distance: 6.25mm (n=251)OCT
signalPhase: Elastic wave velocityIntensity: Speckle variance
Uniaxial mechanical compression testing
Fig: diagram of mechanical compression testingFig: Schematic
diagram of PhS-SSOCT
Quantification of elasticity from OCE Displacement profile
Where 0 was the central wavelength of the laser source, and was
the phase of OCT signal, and n was the refractive index.
Elasticity quantification:Time delay tCross-correlation
analysisElastic group Velocity can be expressed as:Youngs modulus
[1]:
where =1100 kg/m3 was the density of the tissue, =0.5 was the
Poisson ratio [1] Shang Wang, J. Li, S. Vantipalli et al., A
focused air-pulse system for optical-coherence-tomography-based
measurements of tissue elasticity, Opt. Lett., 10(7), (2013).
Fig: (left) OCE setup with OCE measurement positions. (left)
typical displacement profileCorresponding to the red point in
(left)
Speckle variance computationSpeckle variance [1]Study the fluid
kinetics during the clearing processProcedurePerform a linear fit
on the OCT A-line signalThe linear fit was then subtracted from the
OCT signalThe speckle variance was determined by a standard
deviation of the slope removed OCT signal
[1]C.-H. Liu, J. Qi, J. Lu et al., Improvement of tissue
analysis and classification using optical coherence tomography
combined with Raman spectroscopy, Journal of Innovative Optical
Health Sciences, 8(2), 1550006 (2014).
Fig: (left) A typical OCT A-line intensity profile with a linear
fit (right) Slope-removed OCT A-line intensity profile with
standard deviation bounds.
ResultSpeckle varianceKinetic glucose diffusion50-140 minOCE
elasticity0-20 min (water absorbance)20-30min(Bound to free water
state)30-140min(water diffused back)
Fig: (upper) Speckle variance, as quantified by the standard
deviation of the slope-removed A-line intensity profile. (lower)
Youngs modulus as estimated by equation (2) utilizing the elastic
wave group velocity as measured by PhS-SSOCE. The cartilage sample
was immersed in 1X PBS for 20min, then in 20% glucose for
120min.
Fig: Stress relaxation mechanism [1][1] E. Sobol, A. Sviridov,
A. Omelchenko et al., Laser reshaping of cartilage, Biotechnology
and Genetic Engineering Reviews, 17(1), 553-578 (2000).Result
Quantitative value differenceAnisotropy of the biomedical
properties [1]
Fig. (upper) Elasticity as measured by PhS-SSOCE and uniaxial
mechanical testing. (lower) Uniaxial mechanical compression
testing. The cartilage sample was immersed in 1X PBS for 20
minutes, then in 20% glucose for 120 minutes.
[1] B. J. F. Wong, K. K. H. Chao, H. K. Kim et al., The Porcine
and Lagomorph Septal Cartilages: Models for Tissue Engineering and
Morphologic Cartilage Research, American Journal of Rhinology,
15(2), 109-116 (2001).
Conclusion The elasticity of the cartilage DecreaseSample
dehydration caused by glucose solution.IncreaseSample hydration by
the water diffused back to the cartilage during mechanical
compression testThe elasticity trend obtained byPhS-SSOCE uniaxial
compression testThe results demonstrate the feasibility of
utilizing OCE to detect and monitor the biomechanical properties
during optical clearing.In Future, Viscosity change characterize
the water content of the cartilage.
are in agreement Lab members
Questions?