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Lan G, Twa MD, Song C, Feng J, Huang Y, Xu J, Qin J, An L, Wei X. In vivo corneal elastography: A topical review of challenges and opportunities. Comput Struct Biotechnol J 2023; 21:2664-2687. [PMID: 37181662 PMCID: PMC10173410 DOI: 10.1016/j.csbj.2023.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/07/2023] [Accepted: 04/12/2023] [Indexed: 05/16/2023] Open
Abstract
Clinical measurement of corneal biomechanics can aid in the early diagnosis, progression tracking, and treatment evaluation of ocular diseases. Over the past two decades, interdisciplinary collaborations between investigators in optical engineering, analytical biomechanical modeling, and clinical research has expanded our knowledge of corneal biomechanics. These advances have led to innovations in testing methods (ex vivo, and recently, in vivo) across multiple spatial and strain scales. However, in vivo measurement of corneal biomechanics remains a long-standing challenge and is currently an active area of research. Here, we review the existing and emerging approaches for in vivo corneal biomechanics evaluation, which include corneal applanation methods, such as ocular response analyzer (ORA) and corneal visualization Scheimpflug technology (Corvis ST), Brillouin microscopy, and elastography methods, and the emerging field of optical coherence elastography (OCE). We describe the fundamental concepts, analytical methods, and current clinical status for each of these methods. Finally, we discuss open questions for the current state of in vivo biomechanics assessment techniques and requirements for wider use that will further broaden our understanding of corneal biomechanics for the detection and management of ocular diseases, and improve the safety and efficacy of future clinical practice.
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Affiliation(s)
- Gongpu Lan
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Michael D Twa
- College of Optometry, University of Houston, Houston, TX 77204, United States
| | - Chengjin Song
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
| | - JinPing Feng
- Institute of Engineering and Technology, Hubei University of Science and Technology, Xianning, Hubei 437100, China
| | - Yanping Huang
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Jingjiang Xu
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Jia Qin
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Lin An
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Xunbin Wei
- Biomedical Engineering Department, Peking University, Beijing 100081, China
- International Cancer Institute, Peking University, Beijing 100191, China
- Institute of Medical Technology, Peking University Health Science Center, Beijing 100191, China
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2
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Tomizawa Y, Daggett DF, Zheng G, Hoshino K. Light microscopy-based elastography for the mechanical characterization of zebrafish somitogenesis. JOURNAL OF BIOPHOTONICS 2023; 16:e202200238. [PMID: 36336921 DOI: 10.1002/jbio.202200238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/25/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023]
Abstract
We evaluated the elasticity of live tissues of zebrafish embryos using label-free optical elastography. We employed a pair of custom-built elastic microcantilevers to gently compress a zebrafish embryo and used optical-tracking analysis to obtain the induced internal strain. We then built a finite element method (FEM) model and matched the strain with the optical analysis. The elastic moduli were found by minimizing the root-mean-square errors between the optical and FEM analyses. We evaluated the average elastic moduli of a developing somite, the overlying ectoderm, and the underlying yolk of seven zebrafish embryos during the early somitogenesis stages. The estimation results showed that the average elastic modulus of the somite increased from 150 to 700 Pa between 4- and 8-somite stages, while those of the ectoderm and the yolk stayed between 100 and 200 Pa, and they did not show significant changes. The result matches well with the developmental process of somitogenesis reported in the literature. This is among the first attempts to quantify spatially-resolved elasticity of embryonic tissues from optical elastography.
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Affiliation(s)
- Yuji Tomizawa
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, USA
| | - David F Daggett
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Guoan Zheng
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, USA
| | - Kazunori Hoshino
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, USA
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Klontzas ME, Protonotarios A. High-Resolution Imaging for the Analysis and Reconstruction of 3D Microenvironments for Regenerative Medicine: An Application-Focused Review. Bioengineering (Basel) 2021; 8:182. [PMID: 34821748 PMCID: PMC8614770 DOI: 10.3390/bioengineering8110182] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/07/2021] [Accepted: 11/08/2021] [Indexed: 11/29/2022] Open
Abstract
The rapid evolution of regenerative medicine and its associated scientific fields, such as tissue engineering, has provided great promise for multiple applications where replacement and regeneration of damaged or lost tissue is required. In order to evaluate and optimise the tissue engineering techniques, visualisation of the material of interest is crucial. This includes monitoring of the cellular behaviour, extracellular matrix composition, scaffold structure, and other crucial elements of biomaterials. Non-invasive visualisation of artificial tissues is important at all stages of development and clinical translation. A variety of preclinical and clinical imaging methods-including confocal multiphoton microscopy, optical coherence tomography, magnetic resonance imaging (MRI), and computed tomography (CT)-have been used for the evaluation of artificial tissues. This review attempts to present the imaging methods available to assess the composition and quality of 3D microenvironments, as well as their integration with human tissues once implanted in the human body. The review provides tissue-specific application examples to demonstrate the applicability of such methods on cardiovascular, musculoskeletal, and neural tissue engineering.
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Affiliation(s)
- Michail E. Klontzas
- Department of Medical Imaging, University Hospital of Heraklion, 71110, Heraklion, Crete, Greece
- Computational Biomedicine Laboratory, Institute of Computer Science, Foundation for Research and Technology (FORTH), 70013 Heraklion, Crete, Greece
- Department of Radiology, School of Medicine, Voutes Campus, University of Crete, 71003 Heraklion, Crete, Greece
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4
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Quince Z, Alonso-Caneiro D, Read SA, Collins MJ. Static compression optical coherence elastography to measure the mechanical properties of soft contact lenses. BIOMEDICAL OPTICS EXPRESS 2021; 12:1821-1833. [PMID: 33996200 PMCID: PMC8086445 DOI: 10.1364/boe.419344] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/12/2021] [Accepted: 02/23/2021] [Indexed: 06/12/2023]
Abstract
In this study, a novel method was developed for estimating the elastic modulus (Young's modulus) of soft contact lens materials using static compression optical coherence elastography. Using a commercially available spectral domain optical coherence tomography instrument, an experimental setup was developed to image a soft contact lens sample before and during compression with a known applied force, from which the lens material's mechanical properties can be derived. A semi-automatic segmentation method using graph-search theory and dynamic processing was used to trace the lens boundaries and to determine key structural changes within the images. To validate the method, five soft contact lens materials with a range of known elastic moduli and water contents were tested. The proposed method was successful in estimating the Young's modulus in the five different soft contact lens materials. It was demonstrated that the method provides highly repeatable measurements, with an intraclass correlation coefficient of >95%. The Young's modulus results were compared to published manufacturer data with no significant difference for four out of the five materials (p > 0.05). These results demonstrate that a static compression optical coherence tomography method can reliably measure the elastic modulus of soft contact lenses. This provides a methodology that can be used to explore in vitro contact lens mechanical properties, but more importantly, may also be extended to study the mechanical characteristics of in vivo or ex vivo tissue, provided that they can be imaged using OCT.
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Zhang Y, Ling Y, Zhang D, Wang M, Purslow C, Yang Y, Li C, Huang Z. Quantitative measurement of mechanical properties in wound healing processes in a corneal stroma model by using vibrational optical coherence elastography (OCE). BIOMEDICAL OPTICS EXPRESS 2021; 12:588-603. [PMID: 33659091 PMCID: PMC7899504 DOI: 10.1364/boe.404096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/16/2020] [Accepted: 11/17/2020] [Indexed: 05/11/2023]
Abstract
Corneal wound healing, caused by frequent traumatic injury to the cornea and increasing numbers of refractive surgeries, has become a vital clinical problem. In the cornea, wound healing is an extremely complicated process. However, little is known about how the biomechanical changes in wound healing response of the cornea. Collagen-based hydrogels incorporating corneal cells are suitable for replicating a three-dimensional (3D) equivalent of the cornea in-vitro. In this study, the mechanical properties of corneal stroma models were quantitatively monitored by a vibrational optical coherence elastography (OCE) system during continuous culture periods. Specifically, human corneal keratocytes were seeded at 5 × 105 cells/mL in the hydrogels with a collagen concentration of 3.0 mg/mL. The elastic modulus of the unwounded constructs increased from 2.950 ± 0.2 kPa to 11.0 ± 1.4 kPa, and the maximum thickness decreased from 1.034 ± 0.1 mm to 0.464 ± 0.09 mm during a 15-day culture period. Furthermore, a traumatic wound in the construct was introduced with a size of 500 µm. The elastic modulus of the neo-tissue in the wound area increased from 1.488 ± 0.4 kPa to 6.639 ± 0.3 kPa over 13 days. This study demonstrates that the vibrational OCE system is capable of quantitative monitoring the changes in mechanical properties of a corneal stroma wound model during continuous culture periods and improves our understanding on corneal wound healing processes.
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Affiliation(s)
- Yilong Zhang
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Yuting Ling
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Duo Zhang
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Mingkai Wang
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Christine Purslow
- Thea Pharmaceuticals Ltd, Keele University Science & Innovation Park, Innovation Way, Stoke-on-Trent, ST5 5NT, UK
| | - Ying Yang
- Guy Hilton Research Center, School of Pharmacy and Bioengineering, Keele University, Stoke-on-Trent, ST4 7QB, UK
| | - Chunhui Li
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Zhihong Huang
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
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6
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Marrese M, Antonovaite N, Nelemans BK, Smit TH, Iannuzzi D. Micro-indentation and optical coherence tomography for the mechanical characterization of embryos: Experimental setup and measurements on chicken embryos. Acta Biomater 2019; 97:524-534. [PMID: 31377425 DOI: 10.1016/j.actbio.2019.07.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 07/29/2019] [Accepted: 07/30/2019] [Indexed: 10/26/2022]
Abstract
The investigation of the mechanical properties of embryos is expected to provide valuable information on the phenomenology of morphogenesis. It is thus believed that, by mapping the viscoelastic features of an embryo at different stages of growth, it may be possible to shed light on the role of mechanics in embryonic development. To contribute to this field, we present a new instrument that can determine spatiotemporal distributions of mechanical properties of embryos over a wide area and with unprecedented accuracy. The method relies on combining ferrule-top micro-indentation, which provides local measurements of viscoelasticity, with Optical Coherence Tomography, which can reveal changes in tissue morphology and help the user identify the indentation point. To prove the working principle, we have collected viscoelasticity maps of fixed and live HH11-HH12 chicken embryos. Our study shows that the instrument can reveal correlations between tissue morphology and mechanical behavior. STATEMENT OF SIGNIFICANCE: Local mechanical properties of soft biological tissue play a crucial role in several biological processes, including cell differentiation, cell migration, and body formation; therefore, measuring tissue properties at high resolution is of great interest in biology and tissue engineering. To provide an efficient method for the biomechanical characterization of soft biological tissues, we introduce a new tool in which the combination of non-invasive Optical Coherence Tomography imaging and depth-controlled indentation measurements allows one to map the viscoelastic properties of biological tissue and investigate correlations between local mechanical features and tissue morphology with unprecedented resolution.
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Singh MS, Thomas A. Photoacoustic elastography imaging: a review. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-15. [PMID: 31041859 PMCID: PMC6990059 DOI: 10.1117/1.jbo.24.4.040902] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 04/05/2019] [Indexed: 05/12/2023]
Abstract
Elastography imaging is a promising tool-in both research and clinical settings-for diagnosis, staging, and therapeutic treatments of various life-threatening diseases (including brain tumors, breast cancers, prostate cancers, and Alzheimer's disease). Large variation in the physical (elastic) properties of tissue, from normal to diseased stages, enables highly sensitive characterization of pathophysiological states of the diseases. On the other hand, over the last decade or so, photoacoustic (PA) imaging-an imaging modality that combines the advantageous features of two separate imaging modalities, i.e., high spatial resolution and high contrast obtainable, respectively, from ultrasound- and optical-based modalities-has been emerging and widely studied. Recently, recovery of elastic properties of soft biological tissues-in addition to prior reported recovery of vital tissue physiological information (Hb, HbO2, SO, and total Hb), noninvasively and nondestructively, with unprecedented spatial resolution (μm) at penetration depth (cm)-has been reported. Studies demonstrating that combined recovery of mechanical tissue properties and physiological information-by a single (PA) imaging unit-pave a promising platform in clinical diagnosis and therapeutic treatments. We offer a comprehensive review of PA imaging technology, focusing on recent advances in relation to elastography. Our review draws out technological challenges pertaining to PA elastography (PAE) imaging, and viable approaches. Currently, PAE imaging is in the nurture stage of its development, where the technology is limited to qualitative study. The prevailing challenges (specifically, quantitative measurements) may be addressed in a similar way by which ultrasound elastography and optical coherence elastography were accredited for quantitative measurements.
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Affiliation(s)
- Mayanglambam Suheshkumar Singh
- Indian Institute of Science Education and Research Thiruvananthapuram (IISER-TVM), School of Physics (SoP), Biomedical Instrumentation and Imaging Laboratory (BIIL), Thiruvananthapuram, Kerala, India
| | - Anjali Thomas
- Indian Institute of Science Education and Research Thiruvananthapuram (IISER-TVM), School of Physics (SoP), Biomedical Instrumentation and Imaging Laboratory (BIIL), Thiruvananthapuram, Kerala, India
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8
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Singh M, Han Z, Li J, Vantipalli S, Aglyamov SR, Twa MD, Larin KV. Quantifying the effects of hydration on corneal stiffness with noncontact optical coherence elastography. J Cataract Refract Surg 2018; 44:1023-1031. [PMID: 30049567 DOI: 10.1016/j.jcrs.2018.03.036] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 02/17/2018] [Accepted: 03/20/2018] [Indexed: 01/08/2023]
Abstract
PURPOSE To quantify the effects of the hydration state on the Young's modulus of the cornea. SETTING Biomedical Optics Laboratory, University of Houston, Houston, Texas, USA. DESIGN Experimental study. METHODS Noncontact, dynamic optical coherence elastography (OCE) measurements were taken of in situ rabbit corneas in the whole eye-globe configuration (n = 10) and at an artificially controlled intraocular pressure of 15 mm Hg. Baseline OCE measurements were taken by topically hydrating the corneas with saline for 1 hour. The corneas were then dehydrated topically with a 20% dextran solution for another hour, and the OCE measurements were repeated. A finite element method was used to quantify the Young's modulus of the corneas based on the OCE measurements. RESULTS The thickness of the corneas shrank considerably after topical addition of the 20% dextran solution (∼680 μm to ∼370 μm), and the OCE-measured elastic-wave speed correspondingly decreased (∼3.2 m/s to ∼2.6 m/s). The finite element method results showed an increase in Young's modulus (500 kPa to 800 kPa) resulting from dehydration and subsequent thinning. CONCLUSION Young's modulus increased significantly as the corneas dehydrated and thinned, showing that corneal geometry and hydration state are critical factors for accurately quantifying corneal biomechanical properties.
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Affiliation(s)
- Manmohan Singh
- From Biomedical Engineering (Singh, Li, Larin) and the College of Optometry (Vantipalli), Mechanical Engineering (Aglyamov), University of Houston, and Molecular Physiology and Biophysics (Larin), Baylor College of Medicine, Houston, Texas, and the School of Optometry (Twa) and Biomedical Engineering (Twa), University of Alabama at Birmingham, Birmingham, Alabama, USA; The School of Naval Architecture (Han), Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China; Interdisciplinary Laboratory of Biophotonics (Larin), Tomsk State University, Tomsk, Russia
| | - Zhaolong Han
- From Biomedical Engineering (Singh, Li, Larin) and the College of Optometry (Vantipalli), Mechanical Engineering (Aglyamov), University of Houston, and Molecular Physiology and Biophysics (Larin), Baylor College of Medicine, Houston, Texas, and the School of Optometry (Twa) and Biomedical Engineering (Twa), University of Alabama at Birmingham, Birmingham, Alabama, USA; The School of Naval Architecture (Han), Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China; Interdisciplinary Laboratory of Biophotonics (Larin), Tomsk State University, Tomsk, Russia
| | - Jiasong Li
- From Biomedical Engineering (Singh, Li, Larin) and the College of Optometry (Vantipalli), Mechanical Engineering (Aglyamov), University of Houston, and Molecular Physiology and Biophysics (Larin), Baylor College of Medicine, Houston, Texas, and the School of Optometry (Twa) and Biomedical Engineering (Twa), University of Alabama at Birmingham, Birmingham, Alabama, USA; The School of Naval Architecture (Han), Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China; Interdisciplinary Laboratory of Biophotonics (Larin), Tomsk State University, Tomsk, Russia
| | - Srilatha Vantipalli
- From Biomedical Engineering (Singh, Li, Larin) and the College of Optometry (Vantipalli), Mechanical Engineering (Aglyamov), University of Houston, and Molecular Physiology and Biophysics (Larin), Baylor College of Medicine, Houston, Texas, and the School of Optometry (Twa) and Biomedical Engineering (Twa), University of Alabama at Birmingham, Birmingham, Alabama, USA; The School of Naval Architecture (Han), Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China; Interdisciplinary Laboratory of Biophotonics (Larin), Tomsk State University, Tomsk, Russia
| | - Salavat R Aglyamov
- From Biomedical Engineering (Singh, Li, Larin) and the College of Optometry (Vantipalli), Mechanical Engineering (Aglyamov), University of Houston, and Molecular Physiology and Biophysics (Larin), Baylor College of Medicine, Houston, Texas, and the School of Optometry (Twa) and Biomedical Engineering (Twa), University of Alabama at Birmingham, Birmingham, Alabama, USA; The School of Naval Architecture (Han), Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China; Interdisciplinary Laboratory of Biophotonics (Larin), Tomsk State University, Tomsk, Russia
| | - Michael D Twa
- From Biomedical Engineering (Singh, Li, Larin) and the College of Optometry (Vantipalli), Mechanical Engineering (Aglyamov), University of Houston, and Molecular Physiology and Biophysics (Larin), Baylor College of Medicine, Houston, Texas, and the School of Optometry (Twa) and Biomedical Engineering (Twa), University of Alabama at Birmingham, Birmingham, Alabama, USA; The School of Naval Architecture (Han), Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China; Interdisciplinary Laboratory of Biophotonics (Larin), Tomsk State University, Tomsk, Russia
| | - Kirill V Larin
- From Biomedical Engineering (Singh, Li, Larin) and the College of Optometry (Vantipalli), Mechanical Engineering (Aglyamov), University of Houston, and Molecular Physiology and Biophysics (Larin), Baylor College of Medicine, Houston, Texas, and the School of Optometry (Twa) and Biomedical Engineering (Twa), University of Alabama at Birmingham, Birmingham, Alabama, USA; The School of Naval Architecture (Han), Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China; Interdisciplinary Laboratory of Biophotonics (Larin), Tomsk State University, Tomsk, Russia.
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9
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Gillies D, Gamal W, Downes A, Reinwald Y, Yang Y, El Haj AJ, Bagnaninchi PO. Real-time and non-invasive measurements of cell mechanical behaviour with optical coherence phase microscopy. Methods 2018; 136:126-133. [PMID: 29080739 DOI: 10.1016/j.ymeth.2017.10.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/12/2017] [Accepted: 10/17/2017] [Indexed: 12/22/2022] Open
Abstract
Cell mechanical behaviour is increasingly recognised as a central biophysical parameter in cancer and stem cell research, and methods of investigating their mechanical behaviour are therefore needed. We have developed a novel qualitative method based on quantitative phase imaging which is capable of investigating cell mechanical behaviour in real-time at cellular resolution using optical coherence phase microscopy (OCPM), and stimulating the cells non-invasively using hydrostatic pressure. The method was exemplified to distinguish between cells with distinct mechanical properties, and transient change induced by Cytochalasin D. We showed the potential of quantitative phase imaging to detect nanoscale intracellular displacement induced by varying hydrostatic pressure in microfluidic channels, reflecting cell mechanical behaviour. Further physical modelling is required to yield quantitative mechanical properties.
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Affiliation(s)
- D Gillies
- MRC Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh, EH16 4UU, UK; Institute for Bioengineering, School of Engineering, The University of Edinburgh, Edinburgh, EH9 3DW, UK
| | - W Gamal
- MRC Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - A Downes
- Institute for Bioengineering, School of Engineering, The University of Edinburgh, Edinburgh, EH9 3DW, UK
| | - Y Reinwald
- Institute for Science and Technology in Medicine, Keele University, Keele, ST4 7QB, UK
| | - Y Yang
- Institute for Science and Technology in Medicine, Keele University, Keele, ST4 7QB, UK
| | - A J El Haj
- Institute for Science and Technology in Medicine, Keele University, Keele, ST4 7QB, UK
| | - P O Bagnaninchi
- MRC Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh, EH16 4UU, UK.
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10
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Sherlock BE, Harvestine JN, Mitra D, Haudenschild A, Hu J, Athanasiou KA, Leach JK, Marcu L. Nondestructive assessment of collagen hydrogel cross-linking using time-resolved autofluorescence imaging. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-9. [PMID: 29512359 PMCID: PMC5839417 DOI: 10.1117/1.jbo.23.3.036004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 01/31/2018] [Indexed: 05/15/2023]
Abstract
We investigate the use of a fiber-based, multispectral fluorescence lifetime imaging (FLIm) system to nondestructively monitor changes in mechanical properties of collagen hydrogels caused by controlled application of widely used cross-linking agents, glutaraldehyde (GTA) and ribose. Postcross-linking, fluorescence lifetime images are acquired prior to the hydrogels being processed by rheological or tensile testing to directly probe gel mechanical properties. To preserve the sterility of the ribose-treated gels, FLIm is performed inside a biosafety cabinet (BSC). A pairwise correlation analysis is used to quantify the relationship between mean hydrogel fluorescence lifetimes and the storage or Young's moduli of the gels. In the GTA study, we observe strong and specific correlations between fluorescence lifetime and the storage and Young's moduli. Similar correlations are not observed in the ribose study and we postulate a reason for this. Finally, we demonstrate the ability of FLIm to longitudinally monitor dynamic cross-link formation. The strength of the GTA correlations and deployment of our fiber-based FLIm system inside the aseptic environment of a BSC suggests that this technique may be a valuable tool for the tissue engineering community where longitudinal assessment of tissue construct maturation in vitro is highly desirable.
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Affiliation(s)
- Benjamin E Sherlock
- University of California, Davis, Department of Biomedical Engineering, Davis, California, United States
| | - Jenna N Harvestine
- University of California, Davis, Department of Biomedical Engineering, Davis, California, United States
| | - Debika Mitra
- University of California, Davis, Department of Biomedical Engineering, Davis, California, United States
| | - Anne Haudenschild
- University of California, Davis, Department of Biomedical Engineering, Davis, California, United States
| | - Jerry Hu
- University of California, Davis, Department of Biomedical Engineering, Davis, California, United States
| | - Kyriacos A Athanasiou
- University of California, Davis, Department of Biomedical Engineering, Davis, California, United States
- UC Davis Health, Department of Orthopaedic Surgery, Sacramento, California, United States
| | - J Kent Leach
- University of California, Davis, Department of Biomedical Engineering, Davis, California, United States
- UC Davis Health, Department of Orthopaedic Surgery, Sacramento, California, United States
| | - Laura Marcu
- University of California, Davis, Department of Biomedical Engineering, Davis, California, United States
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11
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Zhou K, Le N, Huang Z, Li C. High-intensity-focused ultrasound and phase-sensitive optical coherence tomography for high resolution surface acoustic wave elastography. JOURNAL OF BIOPHOTONICS 2018; 11. [PMID: 28700131 DOI: 10.1002/jbio.201700051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 06/27/2017] [Accepted: 06/29/2017] [Indexed: 05/04/2023]
Abstract
Elastography has the ability of quantitatively evaluating the mechanical properties of soft tissue; thus it is helpful for diagnosis and treatment monitoring of many diseases, for example, skin diseases. Surface acoustic waves (SAWs) have been proven to be a non-invasive, non-destructive method for accurate characterization of tissue elastic properties. Current SAW elastography using high-energy laser pulse or mechanical shaker still have some problems. In order to improve SAW elastography in medical application, a new technique was proposed in this paper, which combines high-intensity-focused ultrasound as a SAWs impulse inducer and phase-sensitive optical coherence tomography as a SAWs detector. A 2% agar-agar phantom and ex-vivo porcine skin were tested. The data were processed by a new algorithm based on the Fourier analysis. The results show that the proposed method has the capability of quantifying the elastic properties of soft tissue-mimicking materials. The lateral resolution of the elastogram has been significantly improved and the different layers in heterogeneous material could also been distinguished. Our improved technique of SAW elastography has a large potential to be widely applied in clinical use for skin disease diagnosis and treatment monitoring.
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Affiliation(s)
- Kanheng Zhou
- School of Science and Engineering, University of Dundee, Dundee, UK
| | - Nhan Le
- School of Science and Engineering, University of Dundee, Dundee, UK
| | - Zhihong Huang
- School of Science and Engineering, University of Dundee, Dundee, UK
| | - Chunhui Li
- School of Science and Engineering, University of Dundee, Dundee, UK
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12
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Wang J, Xu Y, Boppart SA. Review of optical coherence tomography in oncology. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-23. [PMID: 29274145 PMCID: PMC5741100 DOI: 10.1117/1.jbo.22.12.121711] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 12/04/2017] [Indexed: 05/06/2023]
Abstract
The application of optical coherence tomography (OCT) in the field of oncology has been prospering over the past decade. OCT imaging has been used to image a broad spectrum of malignancies, including those arising in the breast, brain, bladder, the gastrointestinal, respiratory, and reproductive tracts, the skin, and oral cavity, among others. OCT imaging has initially been applied for guiding biopsies, for intraoperatively evaluating tumor margins and lymph nodes, and for the early detection of small lesions that would often not be visible on gross examination, tasks that align well with the clinical emphasis on early detection and intervention. Recently, OCT imaging has been explored for imaging tumor cells and their dynamics, and for the monitoring of tumor responses to treatments. This paper reviews the evolution of OCT technologies for the clinical application of OCT in surgical and noninvasive interventional oncology procedures and concludes with a discussion of the future directions for OCT technologies, with particular emphasis on their applications in oncology.
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Affiliation(s)
- Jianfeng Wang
- University of Illinois at Urbana-Champaign, Beckman Institute for Advanced Science and Technology, Urbana, Illinois, United States
| | - Yang Xu
- University of Illinois at Urbana-Champaign, Beckman Institute for Advanced Science and Technology, Urbana, Illinois, United States
- University of Illinois at Urbana–Champaign, Department of Electrical and Computer Engineering, Urbana, Illinois, United States
| | - Stephen A. Boppart
- University of Illinois at Urbana-Champaign, Beckman Institute for Advanced Science and Technology, Urbana, Illinois, United States
- University of Illinois at Urbana–Champaign, Department of Electrical and Computer Engineering, Urbana, Illinois, United States
- University of Illinois at Urbana–Champaign, Department of Bioengineering, Urbana, Illinois, United States
- University of Illinois at Urbana–Champaign, Carle–Illinois College of Medicine, Urbana, Illinois, United States
- Address all correspondence to: Stephen A. Boppart, E-mail:
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Kennedy KM, Bhaw-Luximon A, Jhurry D. Cell-matrix mechanical interaction in electrospun polymeric scaffolds for tissue engineering: Implications for scaffold design and performance. Acta Biomater 2017; 50:41-55. [PMID: 28011142 DOI: 10.1016/j.actbio.2016.12.034] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 11/10/2016] [Accepted: 12/15/2016] [Indexed: 12/24/2022]
Abstract
Engineered scaffolds produced by electrospinning of biodegradable polymers offer a 3D, nanofibrous environment with controllable structural, chemical, and mechanical properties that mimic the extracellular matrix of native tissues and have shown promise for a number of tissue engineering applications. The microscale mechanical interactions between cells and electrospun matrices drive cell behaviors including migration and differentiation that are critical to promote tissue regeneration. Recent developments in understanding these mechanical interactions in electrospun environments are reviewed, with emphasis on how fiber geometry and polymer structure impact on the local mechanical properties of scaffolds, how altering the micromechanics cues cell behaviors, and how, in turn, cellular and extrinsic forces exerted on the matrix mechanically remodel an electrospun scaffold throughout tissue development. Techniques used to measure and visualize these mechanical interactions are described. We provide a critical outlook on technological gaps that must be overcome to advance the ability to design, assess, and manipulate the mechanical environment in electrospun scaffolds toward constructs that may be successfully applied in tissue engineering and regenerative medicine. STATEMENT OF SIGNIFICANCE Tissue engineering requires design of scaffolds that interact with cells to promote tissue development. Electrospinning is a promising technique for fabricating fibrous, biomimetic scaffolds. Effects of electrospun matrix microstructure and biochemical properties on cell behavior have been extensively reviewed previously; here, we consider cell-matrix interaction from a mechanical perspective. Micromechanical properties as a driver of cell behavior has been well established in planar substrates, but more recently, many studies have provided new insights into mechanical interaction in fibrillar, electrospun environments. This review provides readers with an overview of how electrospun scaffold mechanics and cell behavior work in a dynamic feedback loop to drive tissue development, and discusses opportunities for improved design of mechanical environments that are conducive to tissue development.
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Larin KV, Sampson DD. Optical coherence elastography - OCT at work in tissue biomechanics [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:1172-1202. [PMID: 28271011 PMCID: PMC5330567 DOI: 10.1364/boe.8.001172] [Citation(s) in RCA: 221] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 01/18/2017] [Accepted: 01/19/2017] [Indexed: 05/18/2023]
Abstract
Optical coherence elastography (OCE), as the use of OCT to perform elastography has come to be known, began in 1998, around ten years after the rest of the field of elastography - the use of imaging to deduce mechanical properties of tissues. After a slow start, the maturation of OCT technology in the early to mid 2000s has underpinned a recent acceleration in the field. With more than 20 papers published in 2015, and more than 25 in 2016, OCE is growing fast, but still small compared to the companion fields of cell mechanics research methods, and medical elastography. In this review, we describe the early developments in OCE, and the factors that led to the current acceleration. Much of our attention is on the key recent advances, with a strong emphasis on future prospects, which are exceptionally bright.
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Affiliation(s)
- Kirill V Larin
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Blvd., Houston, Texas 77204-5060, USA; Department of Molecular Physiology and Biophysics, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas 77030, USA;
| | - David D Sampson
- Optical + Biomedical Engineering Laboratory, School of Electrical, Electronic & Computer Engineering, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia; Centre for Microscopy, Characterisation & Analysis, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia;
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15
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Ling Y, Li C, Feng K, Duncan R, Eisma R, Huang Z, Nabi G. Effects of fixation and preservation on tissue elastic properties measured by quantitative optical coherence elastography (OCE). J Biomech 2016; 49:1009-1015. [PMID: 26903410 DOI: 10.1016/j.jbiomech.2016.02.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 01/21/2016] [Accepted: 02/05/2016] [Indexed: 11/25/2022]
Abstract
Fixed and preserved tissues have been massively used in the development of biomedical equipment and instrumentation. Not only the tissue morphology, but also its mechanical properties need to be considered in the fixation and preservation procedures since mechanical properties have significant influence on the design and performance of such instruments. Understanding the effects of storage and preservation conditions on the mechanical properties of soft tissue has both clinical and experimental significance. To this end, we aimed to study the effects of tissue preservation (by 10% formalin and Thiel fluids) on the elastic properties of five different kinds of fresh tissues from pig and chicken; specifically fat, liver, muscle, tendon and cartilage. The tissue elasticity was measured intensively and strictly within a controlled timeline of 6 months by quantitative optical coherence elastography (OCE) system. Our findings suggest that the elasticity change of tissues in the formalin solution has an ascending trend, but that of Thiel remains almost constant, providing a more real texture and properties.
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Affiliation(s)
- Yuting Ling
- Academic Section of Urology, Division of Imaging Technology, School of Medicine, University of Dundee, Dundee DD1 9SY, Scotland, UK; School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Chunhui Li
- Academic Section of Urology, Division of Imaging Technology, School of Medicine, University of Dundee, Dundee DD1 9SY, Scotland, UK; School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN, Scotland, UK.
| | - Kairui Feng
- School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Robyn Duncan
- Centers for Anatomy and Human Identification, College of Life Sciences, University of Dundee, Dundee DD1 4HN, UK
| | - Roos Eisma
- Centers for Anatomy and Human Identification, College of Life Sciences, University of Dundee, Dundee DD1 4HN, UK
| | - Zhihong Huang
- School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Ghulam Nabi
- Academic Section of Urology, Division of Imaging Technology, School of Medicine, University of Dundee, Dundee DD1 9SY, Scotland, UK
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16
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Application of Elastography for the Noninvasive Assessment of Biomechanics in Engineered Biomaterials and Tissues. Ann Biomed Eng 2016; 44:705-24. [PMID: 26790865 DOI: 10.1007/s10439-015-1542-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/18/2015] [Indexed: 12/11/2022]
Abstract
The elastic properties of engineered biomaterials and tissues impact their post-implantation repair potential and structural integrity, and are critical to help regulate cell fate and gene expression. The measurement of properties (e.g., stiffness or shear modulus) can be attained using elastography, which exploits noninvasive imaging modalities to provide functional information of a material indicative of the regeneration state. In this review, we outline the current leading elastography methodologies available to characterize the properties of biomaterials and tissues suitable for repair and mechanobiology research. We describe methods utilizing magnetic resonance, ultrasound, and optical coherent elastography, highlighting their potential for longitudinal monitoring of implanted materials in vivo, in addition to spatiotemporal limits of each method for probing changes in cell-laden constructs. Micro-elastography methods now allow acquisitions at length scales approaching 5-100 μm in two and three dimensions. Many of the methods introduced in this review are therefore capable of longitudinal monitoring in biomaterials and tissues approaching the cellular scale. However, critical factors such as anisotropy, heterogeneity and viscoelasity-inherent in many soft tissues-are often not fully described and therefore require further advancements and future developments.
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17
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Yoon JH, Yang YJ, Park J, Son H, Park H, Park GS, Ahn CB. Stiffness measurement using terahertz and acoustic waves for biological samples. OPTICS EXPRESS 2015; 23:32671-32678. [PMID: 26699056 DOI: 10.1364/oe.23.032671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A method is proposed to measure sample stiffness using terahertz wave and acoustic stimulation. The stiffness-dependent vibration is measured using terahertz wave (T-ray) during an acoustic stimulation. To quantify the vibration, time of the peak amplitude of the reflected T-ray is measured. In our experiment, the T-ray is asynchronously applied during the period of the acoustic stimulation, and multiple measurements are taken to use the standard deviation and the maximum difference in the peak times to estimate the amplitude of the vibration. Some preliminary results are shown using biological samples.
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18
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Singh M, Wu C, Liu CH, Li J, Schill A, Nair A, Larin KV. Phase-sensitive optical coherence elastography at 1.5 million A-Lines per second. OPTICS LETTERS 2015; 40:2588-91. [PMID: 26030564 PMCID: PMC5451255 DOI: 10.1364/ol.40.002588] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Shear-wave imaging optical coherence elastography (SWI-OCE) is an emerging method for 3D quantitative assessment of tissue local mechanical properties based on imaging and analysis of elastic wave propagation. Current methods for SWI-OCE involve multiple temporal optical coherence tomography scans (M-mode) at different spatial locations across tissue surface (B- and C-modes). This requires an excitation for each measurement position leading to clinically unacceptable long acquisition times up to tens of minutes. In this Letter, we demonstrate, for the first time, noncontact true kilohertz frame-rate OCE by combining a Fourier domain mode-locked swept source laser with an A-scan rate of ∼1.5 MHz and a focused air-pulse as an elastic wave excitation source. The propagation of the elastic wave in the sample was imaged at a frame rate of ∼7.3 kHz. Therefore, to quantify the elastic wave propagation velocity in a single direction, only a single excitation was needed. This method was validated by quantifying the elasticity of tissue-mimicking agar phantoms as well as of a porcine cornea ex vivo at different intraocular pressures. The results demonstrate that this method can reduce the acquisition time of an elastogram to milliseconds.
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Affiliation(s)
- Manmohan Singh
- Department of Biomedical Engineering, University of Houston, Houston, Texas 77004, USA
| | - Chen Wu
- Department of Biomedical Engineering, University of Houston, Houston, Texas 77004, USA
| | - Chih-Hao Liu
- Department of Biomedical Engineering, University of Houston, Houston, Texas 77004, USA
| | - Jiasong Li
- Department of Biomedical Engineering, University of Houston, Houston, Texas 77004, USA
| | - Alexander Schill
- Department of Biomedical Engineering, University of Houston, Houston, Texas 77004, USA
| | - Achuth Nair
- Department of Biomedical Engineering, University of Houston, Houston, Texas 77004, USA
| | - Kirill V. Larin
- Department of Biomedical Engineering, University of Houston, Houston, Texas 77004, USA
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas 77030, USA
- Interdisciplinary Laboratory of Biophotonics, Tomsk State University, Tomsk 634050, Russia
- Corresponding author:
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19
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Han Z, Li J, Singh M, Wu C, Liu CH, Wang S, Idugboe R, Raghunathan R, Sudheendran N, Aglyamov SR, Twa MD, Larin KV. Quantitative methods for reconstructing tissue biomechanical properties in optical coherence elastography: a comparison study. Phys Med Biol 2015; 60:3531-47. [PMID: 25860076 PMCID: PMC4409577 DOI: 10.1088/0031-9155/60/9/3531] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We present a systematic analysis of the accuracy of five different methods for extracting the biomechanical properties of soft samples using optical coherence elastography (OCE). OCE is an emerging noninvasive technique, which allows assessment of biomechanical properties of tissues with micrometer spatial resolution. However, in order to accurately extract biomechanical properties from OCE measurements, application of a proper mechanical model is required. In this study, we utilize tissue-mimicking phantoms with controlled elastic properties and investigate the feasibilities of four available methods for reconstructing elasticity (Young's modulus) based on OCE measurements of an air-pulse induced elastic wave. The approaches are based on the shear wave equation (SWE), the surface wave equation (SuWE), Rayleigh-Lamb frequency equation (RLFE), and finite element method (FEM), Elasticity values were compared with uniaxial mechanical testing. The results show that the RLFE and the FEM are more robust in quantitatively assessing elasticity than the other simplified models. This study provides a foundation and reference for reconstructing the biomechanical properties of tissues from OCE data, which is important for the further development of noninvasive elastography methods.
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Affiliation(s)
- Zhaolong Han
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX 77204, USA
| | - Jiasong Li
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX 77204, USA
| | - Manmohan Singh
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX 77204, USA
| | - Chen Wu
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX 77204, USA
| | - Chih-hao Liu
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX 77204, USA
| | - Shang Wang
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX 77204, USA
- Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Rita Idugboe
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX 77204, USA
| | - Raksha Raghunathan
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX 77204, USA
| | - Narendran Sudheendran
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX 77204, USA
| | - Salavat R. Aglyamov
- Department of Biomedical Engineering, University of Texas at Austin, 107 W Dean Keeton Street, Austin, TX 78712, USA
| | - Michael D. Twa
- School of Optometry, University of Alabama, Birmingham, AL 35294 USA
| | - Kirill V. Larin
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX 77204, USA
- Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
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20
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Wang S, Larin KV. Optical coherence elastography for tissue characterization: a review. JOURNAL OF BIOPHOTONICS 2015; 8:279-302. [PMID: 25412100 PMCID: PMC4410708 DOI: 10.1002/jbio.201400108] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 10/24/2014] [Accepted: 10/24/2014] [Indexed: 05/05/2023]
Abstract
Optical coherence elastography (OCE) represents the frontier of optical elasticity imaging techniques and focuses on the micro-scale assessment of tissue biomechanics in 3D that is hard to achieve with traditional elastographic methods. Benefit from the advancement of optical coherence tomography, and driven by the increasing requirements in nondestructive biomechanical characterization, this emerging technique recently has experienced a rapid development. In this paper, we start with the description of the mechanical contrast that has been employed by OCE and review the state-of-the-art techniques based on the reported applications and discuss the current technical challenges, emphasizing the unique role of OCE in tissue mechanical characterization. The position of OCE among other elastography techniques.
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Affiliation(s)
- Shang Wang
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Blvd., Houston, Texas, 77204-5060, USA; Department of Molecular Physiology and Biophysics, Baylor College of medicine, one Baylor Plaza, Houston, Texas, 77030, USA
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21
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Detection and characterisation of biopsy tissue using quantitative optical coherence elastography (OCE) in men with suspected prostate cancer. Cancer Lett 2014; 357:121-128. [PMID: 25444932 DOI: 10.1016/j.canlet.2014.11.021] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 10/28/2014] [Accepted: 11/07/2014] [Indexed: 01/18/2023]
Abstract
We present first quantitative three-dimensional (3D) data sets recorded using optical coherence elastography (OCE) for the diagnosis and detection of prostate cancer (PCa). 120 transrectal ultrasound guided prostate biopsy specimens from 10 men suspected with prostate cancer were imaged using OCE. 3D quantitative mechanical assessment of biopsy specimens obtained in kilopascals (kPa) at an interval of 40 µm was compared with histopathology. Sensitivity, specificity, and positive and negative predictive values were calculated for OCE in comparison to histopathology. The results show OCE imaging could reliably differentiate between benign prostate tissue, acinar atypical hyperplasia, prostatic intraepithelial neoplasia and malignant PCa. The sensitivity and specificity of OCE for the detection of prostate cancer was 0.98 and 0.91 with AUC > 0.99. Quantitative 3D OCE based on the assessment of mechanical properties of tissues can reliably differentiate prostate tissue specimen in an ex-vivo setting. This is a promising imaging modality for characterising different grades of cancers.
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22
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Liu P, Groves RM, Benedictus R. Optical coherence elastography for measuring the deformation within glass fiber composite. APPLIED OPTICS 2014; 53:5070-5077. [PMID: 25090343 DOI: 10.1364/ao.53.005070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 06/23/2014] [Indexed: 06/03/2023]
Abstract
Optical coherence elastography (OCE) has been applied to the study of microscopic deformation in biological tissue under compressive stress for more than a decade. In this paper, OCE has been extended for the first time, to the best of our knowledge, to deformation measurement in a glass fiber composite in the field of nondestructive testing. A customized optical coherence tomography system, combined with a mechanical loading setup, was developed to provide pairs of prestressed and stressed structural images. The speckle tracking algorithm, based on 2D cross correlation, was used to estimate the local displacements in micrometer scale. The algorithm was first evaluated by a test of rigid body translation. Then the experiments were carried out with the tensile test and three point bending on a set of glass fiber composites. The structural features and structural variations during the mechanical loadings are clearly observed with the presented displacement maps. The advantages and prospects for OCE application on glass fiber composites are discussed at the end of this paper.
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23
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Li C, Guan G, Zhang F, Nabi G, Wang RK, Huang Z. Laser induced surface acoustic wave combined with phase sensitive optical coherence tomography for superficial tissue characterization: a solution for practical application. BIOMEDICAL OPTICS EXPRESS 2014; 5:1403-19. [PMID: 24877004 PMCID: PMC4026889 DOI: 10.1364/boe.5.001403] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 03/24/2014] [Accepted: 03/25/2014] [Indexed: 05/02/2023]
Abstract
Mechanical properties are important parameters that can be used to assess the physiologic conditions of biologic tissue. Measurements and mapping of tissue mechanical properties can aid in the diagnosis, characterisation and treatment of diseases. As a non-invasive, non-destructive and non-contact method, laser induced surface acoustic waves (SAWs) have potential to accurately characterise tissue elastic properties. However, challenge still exists when the laser is directly applied to the tissue because of potential heat generation due to laser energy deposition. This paper focuses on the thermal effect of the laser induced SAW on the tissue target and provides an alternate solution to facilitate its application in clinic environment. The solution proposed is to apply a thin agar membrane as surface shield to protect the tissue. Transient thermal analysis is developed and verified by experiments to study the effects of the high energy Nd:YAG laser pulse on the surface shield. The approach is then verified by measuring the mechanical property of skin in a Thiel mouse model. The results demonstrate a useful step toward the practical application of laser induced SAW method for measuring real elasticity of normal and diseased tissues in dermatology and other surface epithelia.
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Affiliation(s)
- Chunhui Li
- Division of Imaging Technology, School of Medicine, University of Dundee, Dundee DD1 9SY, Scotland, UK
| | - Guangying Guan
- School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN, Scotland, UK ; Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
| | - Fan Zhang
- School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Ghulam Nabi
- Division of Imaging Technology, School of Medicine, University of Dundee, Dundee DD1 9SY, Scotland, UK
| | - Ruikang K Wang
- School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN, Scotland, UK ; Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
| | - Zhihong Huang
- School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN, Scotland, UK
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24
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Qi W, Li R, Ma T, Kirk Shung K, Zhou Q, Chen Z. Confocal acoustic radiation force optical coherence elastography using a ring ultrasonic transducer. APPLIED PHYSICS LETTERS 2014; 104:123702. [PMID: 24737920 PMCID: PMC3971820 DOI: 10.1063/1.4869562] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 03/13/2014] [Indexed: 05/17/2023]
Abstract
We designed and developed a confocal acoustic radiation force optical coherence elastography system. A ring ultrasound transducer was used to achieve reflection mode excitation and generate an oscillating acoustic radiation force in order to generate displacements within the tissue, which were detected using the phase-resolved optical coherence elastography method. Both phantom and human tissue tests indicate that this system is able to sense the stiffness difference of samples and quantitatively map the elastic property of materials. Our confocal setup promises a great potential for point by point elastic imaging in vivo and differentiation of diseased tissues from normal tissue.
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Affiliation(s)
- Wenjuan Qi
- Beckman Laser Institute, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92612, USA ; Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, USA
| | - Rui Li
- Beckman Laser Institute, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92612, USA
| | - Teng Ma
- Department of Biomedical Engineering, NIH Ultrasonic Transducer Resource Center, University of Southern California, Los Angeles, California 90089, USA
| | - K Kirk Shung
- Department of Biomedical Engineering, NIH Ultrasonic Transducer Resource Center, University of Southern California, Los Angeles, California 90089, USA
| | - Qifa Zhou
- Department of Biomedical Engineering, NIH Ultrasonic Transducer Resource Center, University of Southern California, Los Angeles, California 90089, USA
| | - Zhongping Chen
- Beckman Laser Institute, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92612, USA ; Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, USA ; Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92697, USA
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25
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Li F, Xu T, Nguyen DHT, Huang X, Chen CS, Zhou C. Label-free evaluation of angiogenic sprouting in microengineered devices using ultrahigh-resolution optical coherence microscopy. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:16006. [PMID: 24395588 PMCID: PMC3881608 DOI: 10.1117/1.jbo.19.1.016006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 12/09/2013] [Accepted: 12/10/2013] [Indexed: 05/29/2023]
Abstract
Understanding the mechanism of angiogenesis could help to decipher wound healing and embryonic development and to develop better treatment for diseases such as cancer. Microengineered devices were developed to reveal the mechanisms of angiogenesis, but monitoring the angiogenic process nondestructively in these devices is a challenge. In this study, we utilized a label-free imaging technique, ultrahigh-resolution optical coherence microscopy (OCM), to evaluate angiogenic sprouting in a microengineered device. The OCM system was capable of providing ∼1.5-μm axial resolution and ∼2.3-μm transverse resolution. Three-dimensional (3-D) distribution of the sprouting vessels in the microengineered device was imaged over 0.6×0.6×0.5 mm3, and details such as vessel lumens and branching points were clearly visualized. An algorithm based on stretching open active contours was developed for tracking and segmenting the sprouting vessels in 3-D-OCM images. The lengths for the first-, second-, and third-order vessels were measured as 127.8±48.8 μm (n=8), 67.3±25.9 μm (n=9), and 62.5±34.7 μm (n=10), respectively. The outer diameters for the first-, second-, and third-order vessels were 13.2±1.0, 8.0±2.1, and 4.4±0.8 μm, respectively. These results demonstrate OCM as a promising tool for nondestructive and label-free evaluation of angiogenic sprouting in microengineered devices.
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Affiliation(s)
- Fengqiang Li
- Lehigh University, Department of Electrical and Computer Engineering, Bethlehem, Pennsylvania 18015
- Lehigh University, Center for Photonics and Nanoelectronics, Bethlehem, Pennsylvania 18015
| | - Ting Xu
- Lehigh University, Department of Computer Science and Engineering, Bethlehem, Pennsylvania 18015
| | - Duc-Huy T. Nguyen
- University of Pennsylvania, Department of Chemical and Biomolecular Engineering, Philadelphia, Pennsylvania 19104
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts 02115
- Harvard University, Wyss Institute for Biologically Inspired Engineering, Boston, Massachusetts 02115
| | - Xiaolei Huang
- Lehigh University, Department of Computer Science and Engineering, Bethlehem, Pennsylvania 18015
- Lehigh University, Bioengineering Program, Bethlehem, Pennsylvania 18015
| | - Christopher S. Chen
- University of Pennsylvania, Department of Chemical and Biomolecular Engineering, Philadelphia, Pennsylvania 19104
- University of Pennsylvania, Department of Bioengineering, Philadelphia, Pennsylvania 19104
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts 02115
- Harvard University, Wyss Institute for Biologically Inspired Engineering, Boston, Massachusetts 02115
| | - Chao Zhou
- Lehigh University, Department of Electrical and Computer Engineering, Bethlehem, Pennsylvania 18015
- Lehigh University, Center for Photonics and Nanoelectronics, Bethlehem, Pennsylvania 18015
- Lehigh University, Bioengineering Program, Bethlehem, Pennsylvania 18015
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Doyley MM, Parker KJ. Elastography: general principles and clincial applications. ACTA ACUST UNITED AC 2014; 9:1-11. [PMID: 24459461 DOI: 10.1016/j.cult.2013.09.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- M M Doyley
- University of Rochester, Department of Electrical and Computer Engineering, Hopeman, Engineering Building 343, Box 270126, Rochester, NY 14627, USA
| | - K J Parker
- University of Rochester, Department of Electrical and Computer Engineering, Hopeman, Engineering Building 343, Box 270126, Rochester, NY 14627, USA
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27
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Kennedy BF, Malheiro FG, Chin L, Sampson DD. Three-dimensional optical coherence elastography by phase-sensitive comparison of C-scans. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:076006. [PMID: 25003754 DOI: 10.1117/1.jbo.19.7.076006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 06/09/2014] [Indexed: 05/02/2023]
Abstract
We present an acquisition method for optical coherence elastography (OCE) that enables acquisition of three-dimensional elastograms in 5 s, an order of magnitude faster than previously reported. In this method, based on compression elastography, the mechanical load applied to the sample is altered between acquisitions of consecutive optical coherence tomography volume scans (C-scans). The voxel-by-voxel phase difference between the volumes is used to determine the axial displacement and determining the gradient of the axial displacement versus depth gives the local axial strain. We demonstrate sub-100-microstrain sensitivity and high contrast in elastograms, acquired in 5 s, of structured phantoms and freshly excised rat muscle tissue that are comparable in strain sensitivity and dynamic range to our previously reported B-scan-based method. The much higher acquisition speed may expedite the translation of OCE to clinical and in vivo applications.
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Affiliation(s)
- Brendan F Kennedy
- The University of Western Australia, School of Electrical, Electronic and Computer Engineering, Optical+Biomedical Engineering Laboratory, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Francisco Gomes Malheiro
- The University of Western Australia, School of Electrical, Electronic and Computer Engineering, Optical+Biomedical Engineering Laboratory, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Lixin Chin
- The University of Western Australia, School of Electrical, Electronic and Computer Engineering, Optical+Biomedical Engineering Laboratory, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - David D Sampson
- The University of Western Australia, School of Electrical, Electronic and Computer Engineering, Optical+Biomedical Engineering Laboratory, 35 Stirling Highway, Crawley, Western Australia 6009, AustraliabThe University of Western Australia, Centre for Micr
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Nguyen TM, Song S, Arnal B, Wong EY, Huang Z, Wang RK, O’Donnell M. Shear wave pulse compression for dynamic elastography using phase-sensitive optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:16013. [PMID: 24441876 PMCID: PMC3894424 DOI: 10.1117/1.jbo.19.1.016013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 12/09/2013] [Indexed: 05/04/2023]
Abstract
Assessing the biomechanical properties of soft tissue provides clinically valuable information to supplement conventional structural imaging. In the previous studies, we introduced a dynamic elastography technique based on phase-sensitive optical coherence tomography (PhS-OCT) to characterize submillimetric structures such as skin layers or ocular tissues. Here, we propose to implement a pulse compression technique for shear wave elastography. We performed shear wave pulse compression in tissue-mimicking phantoms. Using a mechanical actuator to generate broadband frequency-modulated vibrations (1 to 5 kHz), induced displacements were detected at an equivalent frame rate of 47 kHz using a PhS-OCT. The recorded signal was digitally compressed to a broadband pulse. Stiffness maps were then reconstructed from spatially localized estimates of the local shear wave speed. We demonstrate that a simple pulse compression scheme can increase shear wave detection signal-to-noise ratio (>12 dB gain) and reduce artifacts in reconstructing stiffness maps of heterogeneous media.
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Affiliation(s)
- Thu-Mai Nguyen
- University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195
- Address all correspondence to: Thu-Mai Nguyen, E-mail:
| | - Shaozhen Song
- University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195
- University of Dundee, School of Engineering, Physics and Mathematics, Scotland, United Kingdom
| | - Bastien Arnal
- University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195
| | - Emily Y. Wong
- University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195
| | - Zhihong Huang
- University of Dundee, School of Engineering, Physics and Mathematics, Scotland, United Kingdom
| | - Ruikang K. Wang
- University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195
- University of Washington, Department of Ophthalmology, 325 9th Avenue, Seattle, Washington 98104
| | - Matthew O’Donnell
- University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195
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29
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Song S, Huang Z, Nguyen TM, Wong EY, Arnal B, O’Donnell M, Wang RK. Shear modulus imaging by direct visualization of propagating shear waves with phase-sensitive optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2013; 18:121509. [PMID: 24213539 PMCID: PMC4019419 DOI: 10.1117/1.jbo.18.12.121509] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 10/17/2013] [Indexed: 05/12/2023]
Abstract
We propose an integrated method combining low-frequency mechanics with optical imaging to map the shear modulus within the biological tissue. Induced shear wave propagating in tissue is tracked in space and time using phase-sensitive optical coherence tomography (PhS-OCT). Local estimates of the shear-wave speed obtained from tracking results can image the local shear modulus. A PhS-OCT system remotely records depth-resolved, dynamic mechanical waves at an equivalent frame rate of ∼47 kHz with the high spatial resolution. The proposed method was validated by examining tissue-mimicking phantoms made of agar and light scattering material. Results demonstrate that the shear wave imaging can accurately map the elastic moduli of these phantoms.
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Affiliation(s)
- Shaozhen Song
- University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195
- University of Dundee, School of Engineering, Physics and Mathematics, Dundee DD1 4HN, Scotland, UK
| | - Zhihong Huang
- University of Dundee, School of Engineering, Physics and Mathematics, Dundee DD1 4HN, Scotland, UK
| | - Thu-Mai Nguyen
- University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195
| | - Emily Y. Wong
- University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195
| | - Bastien Arnal
- University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195
| | - Matthew O’Donnell
- University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195
| | - Ruikang K. Wang
- University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195
- University of Washington, Department of Ophthalmology, 325 9th Avenue, Seattle, Washington 98104
- Address all correspondence to: Ruikang K. Wang, University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195. Tel: 206 6165025; Fax: 206-685-3300; E-mail:
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30
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Au KM, Lu Z, Matcher SJ, Armes SP. Anti-biofouling conducting polymer nanoparticles as a label-free optical contrast agent for high resolution subsurface biomedical imaging. Biomaterials 2013; 34:8925-40. [DOI: 10.1016/j.biomaterials.2013.07.094] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 07/29/2013] [Indexed: 02/02/2023]
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Appel AA, Anastasio MA, Larson JC, Brey EM. Imaging challenges in biomaterials and tissue engineering. Biomaterials 2013; 34:6615-30. [PMID: 23768903 PMCID: PMC3799904 DOI: 10.1016/j.biomaterials.2013.05.033] [Citation(s) in RCA: 167] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 05/18/2013] [Indexed: 12/11/2022]
Abstract
Biomaterials are employed in the fields of tissue engineering and regenerative medicine (TERM) in order to enhance the regeneration or replacement of tissue function and/or structure. The unique environments resulting from the presence of biomaterials, cells, and tissues result in distinct challenges in regards to monitoring and assessing the results of these interventions. Imaging technologies for three-dimensional (3D) analysis have been identified as a strategic priority in TERM research. Traditionally, histological and immunohistochemical techniques have been used to evaluate engineered tissues. However, these methods do not allow for an accurate volume assessment, are invasive, and do not provide information on functional status. Imaging techniques are needed that enable non-destructive, longitudinal, quantitative, and three-dimensional analysis of TERM strategies. This review focuses on evaluating the application of available imaging modalities for assessment of biomaterials and tissue in TERM applications. Included is a discussion of limitations of these techniques and identification of areas for further development.
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Affiliation(s)
- Alyssa A. Appel
- Department of Biomedical Engineering, Illinois Institute of Technology, 3255 South Dearborn St, Chicago, IL 60616, USA
- Research Service, Hines Veterans Administration Hospital, Hines, IL, USA
| | - Mark A. Anastasio
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Jeffery C. Larson
- Department of Biomedical Engineering, Illinois Institute of Technology, 3255 South Dearborn St, Chicago, IL 60616, USA
- Research Service, Hines Veterans Administration Hospital, Hines, IL, USA
| | - Eric M. Brey
- Department of Biomedical Engineering, Illinois Institute of Technology, 3255 South Dearborn St, Chicago, IL 60616, USA
- Research Service, Hines Veterans Administration Hospital, Hines, IL, USA
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32
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Hong YR, Wu YL, Luo ZY, Wu NB, Liu XM. Impact of nodular size on the predictive values of gray-scale, color-Doppler ultrasound, and sonoelastography for assessment of thyroid nodules. J Zhejiang Univ Sci B 2013; 13:707-16. [PMID: 22949361 DOI: 10.1631/jzus.b1100342] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To define the roles of gray-scale, color-Doppler ultrasound, and sonoelastography for the assessment of thyroid nodule to determine whether nodule size affects the differential diagnosis of benign and malignant. METHODS A total of 243 consecutive subjects (214 women, 29 men) with 329 thyroid nodules were examined by gray-scale, color-Doppler ultrasound, and sonoelastography in this prospective study. All patients underwent surgery and the final diagnosis was obtained from histopathological examination. RESULTS Three hundred and twenty-nine nodules (208 benign, 121 malignant) were divided into small (SNs, 5-10 mm, n=137) and large (LNs, >10 mm, n=192) nodules. Microcalcifications were more frequent in malignant LNs than in malignant SNs, but showed no significant difference between benign LNs and SNs. Poorly-circumscribed margins were not significantly different between malignant SNs and LNs, but were less frequent in benign LNs than in benign SNs. Among all nodules, marked intranodular vascularity was more frequent in LNs than in SNs. By comparison, shape ratio of anteroposterior to transverse dimensions (A/T) ≥ 1 was less frequent in LNs than in SNs. Otherwise, among all nodules, marked hypoechogenicity and elasticity score of 4-6 showed no significant difference between LNs and SNs. CONCLUSIONS The predictive values of microcalcifications, nodular margins, A/T ratio, and marked intranodular vascularity depend on nodule size, but the predictive values of echogenicity and elastography do not.
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Affiliation(s)
- Yu-rong Hong
- Department of Ultrasound, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China
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33
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Couet F, Mantovani D. Perspectives on the advanced control of bioreactors for functional vascular tissue engineering in vitro. Expert Rev Med Devices 2012; 9:233-9. [PMID: 22702253 DOI: 10.1586/erd.12.15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Tissue engineering aims to produce tissues using cells and materials. The action of designing tissues involves observing the process of growth to understand its underlying mechanisms. It requires manipulation of the critical parameters for cell growth and remodeling to produce structured tissues and functional organs. Tissue engineers face the challenge of orchestrating the signals in a cell's microenvironment to efficiently grow an anisotropic and hierarchical tissue. It can be performed in vivo through the design of bioactive scaffolds and manipulation of biological signals using growth factors. It can also be performed in vitro in a controlled environment called the bioreactor. This article addresses the matter of finding the optimal dynamic sequence of culture conditions in a bioreactor for the maturation of tissues. Artificial intelligence and optimal control are accelerating technologies towards an understanding of tissue regeneration. The particular example of the functional engineering of small-diameter blood vessels has been chosen to illustrate this idea.
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Affiliation(s)
- Frédéric Couet
- Laboratory for Biomaterials and Bioengineering, Department of Min-Met-Materials Engineering and University Hospital Research Center, Laval University, Québec City, QC, G1V 0A6, Canada
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34
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Kennedy BF, Koh SH, McLaughlin RA, Kennedy KM, Munro PRT, Sampson DD. Strain estimation in phase-sensitive optical coherence elastography. BIOMEDICAL OPTICS EXPRESS 2012; 3:1865-79. [PMID: 22876350 PMCID: PMC3409705 DOI: 10.1364/boe.3.001865] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 06/28/2012] [Accepted: 07/12/2012] [Indexed: 05/02/2023]
Abstract
We present a theoretical framework for strain estimation in optical coherence elastography (OCE), based on a statistical analysis of displacement measurements obtained from a mechanically loaded sample. We define strain sensitivity, signal-to-noise ratio and dynamic range, and derive estimates of strain using three methods: finite difference, ordinary least squares and weighted least squares, the latter implemented for the first time in OCE. We compare theoretical predictions with experimental results and demonstrate a ~12 dB improvement in strain sensitivity using weighted least squares compared to finite difference strain estimation and a ~4 dB improvement over ordinary least squares strain estimation. We present strain images (i.e., elastograms) of tissue-mimicking phantoms and excised porcine airway, demonstrating in each case clear contrast based on the sample's elasticity.
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Affiliation(s)
- Brendan F. Kennedy
- Optical + Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Sze Howe Koh
- Optical + Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Robert A. McLaughlin
- Optical + Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Kelsey M. Kennedy
- Optical + Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Peter R. T. Munro
- Optical + Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - David D. Sampson
- Optical + Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
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35
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Li C, Guan G, Reif R, Huang Z, Wang RK. Determining elastic properties of skin by measuring surface waves from an impulse mechanical stimulus using phase-sensitive optical coherence tomography. J R Soc Interface 2012; 51:908-12. [PMID: 22048946 DOI: 10.1109/tuffc.2004.1320751] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023] Open
Abstract
The mechanical properties of skin are important tissue parameters that are useful for understanding skin patho-physiology, which can aid disease diagnosis and treatment. This paper presents an innovative method that employs phase-sensitive spectral-domain optical coherence tomography (PhS-OCT) to characterize the biomechanical properties of skin by measuring surface waves induced by short impulses from a home-made shaker. Experiments are carried out on single and double-layer agar-agar phantoms, of different concentrations and thickness, and on in vivo human skin, at the forearm and the palm. For each experiment, the surface wave phase-velocity dispersion curves were calculated, from which the elasticity of each layer of the sample was determined. It is demonstrated that the experimental results agree well with previous work. This study provides a novel combination of PhS-OCT technology with a simple and an inexpensive mechanical impulse surface wave stimulation that can be used to non-invasively evaluate the mechanical properties of skin in vivo, and may offer potential use in clinical situations.
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Affiliation(s)
- Chunhui Li
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
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36
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Li C, Guan G, Li S, Huang Z, Wang RK. Evaluating elastic properties of heterogeneous soft tissue by surface acoustic waves detected by phase-sensitive optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:057002. [PMID: 22612141 DOI: 10.1117/1.jbo.17.5.057002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The combined use of surface acoustic wave (SAW) and phase-sensitive optical coherence tomography (PhS-OCT) is useful to evaluate the elasticity of layered biological tissues, such as normal skin. However, the pathological tissue is often originated locally, leading to the alternation of mechanical properties along both axial and lateral directions. We present a feasibility study on whether the SAW technique is sensitive to detect the alternation of mechanical property along the lateral direction within tissue, which is important for clinical utility of this technique to localize diseased tissue. Experiments are carried out on purposely designed tissue phantoms and ex vivo chicken breast samples, simulating the localized change of elasticity. A PhS-OCT system is employed not only to provide the ultra-high sensitive measurement of the generated surface waves on the tissue surface, but also to provide the real time imaging of the tissue to assist the elasticity evaluation of the heterogeneous tissue. The experimental results demonstrate that with PhS-OCT used as a pressure sensor, the SAW is highly sensitive to the elasticity change of the specimen in both vertical and lateral directions with a sensing depth of ∼5 mm with our current system setup, thus promising its useful clinical applications where the quantitative elasticity of localized skin diseases is needed to aid in diagnosis and treatment.
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Affiliation(s)
- Chunhui Li
- University of Washington, Department of Bioengineering, Seattle, WA 98195, USA
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37
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Zhao Y, Graf BW, Chaney EJ, Mahmassani Z, Antoniadou E, DeVolder R, Kong H, Boppart MD, Boppart SA. Integrated multimodal optical microscopy for structural and functional imaging of engineered and natural skin. JOURNAL OF BIOPHOTONICS 2012; 5:437-48. [PMID: 22371330 PMCID: PMC4486208 DOI: 10.1002/jbio.201200003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 02/07/2012] [Accepted: 02/07/2012] [Indexed: 05/21/2023]
Abstract
An integrated multimodal optical microscope is demonstrated for high-resolution, structural and functional imaging of engineered and natural skin. This microscope incorporates multiple imaging modalities including optical coherence (OCM), multi-photon (MPM), and fluorescence lifetime imaging microscopy (FLIM), enabling simultaneous visualization of multiple contrast sources and mechanisms from cells and tissues. Spatially co-registered OCM/MPM/FLIM images of multi-layered skin tissues are obtained, which are formed based on complementary information provided by different modalities, i.e., scattering information from OCM, molecular information from MPM, and functional cellular metabolism states from FLIM. Cellular structures in both the dermis and epidermis, especially different morphological and physiological states of keratinocytes from different epidermal layers, are revealed by mutually-validating images. In vivo imaging of human skin is also investigated, which demonstrates the potential of multimodal microscopy for in vivo investigation during engineered skin engraftment. This integrated imaging technique and microscope show the potential for investigating cellular dynamics in developing engineered skin and following in vivo grafting, which will help refine the control and culturing conditions necessary to obtain more robust and physiologically-relevant engineered skin substitutes.
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Affiliation(s)
- Youbo Zhao
- Biophotonics Imaging Laboratory, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Benedikt W. Graf
- Biophotonics Imaging Laboratory, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Eric J. Chaney
- Biophotonics Imaging Laboratory, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ziad Mahmassani
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Eleni Antoniadou
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ross DeVolder
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Hyunjoon Kong
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Marni D. Boppart
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Stephen A. Boppart
- Biophotonics Imaging Laboratory, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Internal Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Corresponding author: , Phone: +1 217 244 7479, Fax: +1 217 333 5833
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38
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Othman SF, Curtis ET, Plautz SA, Pannier AK, Butler SD, Xu H. MR elastography monitoring of tissue-engineered constructs. NMR IN BIOMEDICINE 2012; 25:452-463. [PMID: 21387443 DOI: 10.1002/nbm.1663] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Revised: 11/15/2010] [Accepted: 12/03/2010] [Indexed: 05/30/2023]
Abstract
The objective of tissue engineering (TE) is to create functional replacements for various tissues; the mechanical properties of these engineered constructs are critical to their function. Several techniques have been developed for the measurement of the mechanical properties of tissues and organs; however, current methods are destructive. The field of TE will benefit immensely if biomechanical models developed by these techniques could be combined with existing imaging modalities to enable noninvasive, dynamic assessment of mechanical properties during tissue growth. Specifically, MR elastography (MRE), which is based on the synchronization of a mechanical actuator with a phase contrast imaging pulse sequence, has the capacity to measure tissue strain generated by sonic cyclic displacement. The captured displacement is presented in shear wave images from which the complex shear moduli can be extracted or simplified by a direct measure, termed the shear stiffness. MRE has been extended to the microscopic scale, combining clinical MRE with high-field magnets, stronger magnetic field gradients and smaller, more sensitive, radiofrequency coils, enabling the interrogation of smaller samples, such as tissue-engineered constructs. The following topics are presented in this article: (i) current mechanical measurement techniques and their limitations in TE; (ii) a description of the MRE system, MRE theory and how it can be applied for the measurement of mechanical properties of tissue-engineered constructs; (iii) a summary of in vitro MRE work for the monitoring of osteogenic and adipogenic tissues originating from human adult mesenchymal stem cells (MSCs); (iv) preliminary in vivo studies of MRE of tissues originating from mouse MSCs implanted subcutaneously in immunodeficient mice with an emphasis on in vivo MRE challenges; (v) future directions to resolve current issues with in vivo MRE in the context of how to improve the future role of MRE in TE.
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Affiliation(s)
- Shadi F Othman
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68583, USA.
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39
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Abstract
Elastography is emerging as an imaging modality that can distinguish normal versus diseased tissues via their biomechanical properties. This paper reviews current approaches to elastography in three areas--quasi-static, harmonic and transient--and describes inversion schemes for each elastographic imaging approach. Approaches include first-order approximation methods; direct and iterative inversion schemes for linear elastic; isotropic materials and advanced reconstruction methods for recovering parameters that characterize complex mechanical behavior. The paper's objective is to document efforts to develop elastography within the framework of solving an inverse problem, so that elastography may provide reliable estimates of shear modulus and other mechanical parameters. We discuss issues that must be addressed if model-based elastography is to become the prevailing approach to quasi-static, harmonic and transient elastography: (1) developing practical techniques to transform the ill-posed problem with a well-posed one; (2) devising better forward models to capture the complex mechanical behavior of soft tissues and (3) developing better test procedures to evaluate the performance of modulus elastograms.
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Affiliation(s)
- M M Doyley
- University of Rochester, Department of Electrical and Computer Engineering, Hopeman Engineering Building 413, Box 270126, Rochester, NY 14627, USA.
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40
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Li C, Guan G, Reif R, Huang Z, Wang RK. Determining elastic properties of skin by measuring surface waves from an impulse mechanical stimulus using phase-sensitive optical coherence tomography. J R Soc Interface 2011; 9:831-41. [PMID: 22048946 DOI: 10.1098/rsif.2011.0583] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The mechanical properties of skin are important tissue parameters that are useful for understanding skin patho-physiology, which can aid disease diagnosis and treatment. This paper presents an innovative method that employs phase-sensitive spectral-domain optical coherence tomography (PhS-OCT) to characterize the biomechanical properties of skin by measuring surface waves induced by short impulses from a home-made shaker. Experiments are carried out on single and double-layer agar-agar phantoms, of different concentrations and thickness, and on in vivo human skin, at the forearm and the palm. For each experiment, the surface wave phase-velocity dispersion curves were calculated, from which the elasticity of each layer of the sample was determined. It is demonstrated that the experimental results agree well with previous work. This study provides a novel combination of PhS-OCT technology with a simple and an inexpensive mechanical impulse surface wave stimulation that can be used to non-invasively evaluate the mechanical properties of skin in vivo, and may offer potential use in clinical situations.
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Affiliation(s)
- Chunhui Li
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
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41
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Robertson C, Lee SW, Ahn YC, Mahon S, Chen Z, Brenner M, George SC. Investigating in vivo airway wall mechanics during tidal breathing with optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:106011. [PMID: 22029358 PMCID: PMC3210193 DOI: 10.1117/1.3642006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Optical coherence tomography (OCT) is a nondestructive imaging technique offering high temporal and spatial resolution, which makes it a natural choice for assessing tissue mechanical properties. We have developed methods to mechanically analyze the compliance of the rabbit trachea in vivo using tissue deformations induced by tidal breathing, offering a unique tool to assess the behavior of the airways during their normal function. Four-hundred images were acquired during tidal breathing with a custom-built endoscopic OCT system. The surface of the tissue was extracted from a set of these images via image processing algorithms, filtered with a bandpass filter set at respiration frequency to remove cardiac and probe motion, and compared to ventilatory pressure to calculate wall compliance. These algorithms were tested on elastic phantoms to establish reliability and reproducibility. The mean tracheal wall compliance (in five animals) was 1.3±0.3×10(-5) (mm Pa)(-1). Unlike previous work evaluating airway mechanics, this new method is applicable in vivo, noncontact, and loads the trachea in a physiological manner. The technique may have applications in assessing airway mechanics in diseases such as asthma that are characterized by significant airway remodeling.
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Affiliation(s)
- Claire Robertson
- University of California, Irvine, Department of Biomedical Engineering, Irvine, California 92697, USA
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Sun C, Standish B, Yang VXD. Optical coherence elastography: current status and future applications. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:043001. [PMID: 21529067 DOI: 10.1117/1.3560294] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Optical coherence tomography (OCT) has several advantages over other imaging modalities, such as angiography and ultrasound, due to its inherently high in vivo resolution, which allows for the identification of morphological tissue structures. Optical coherence elastography (OCE) benefits from the superior spatial resolution of OCT and has promising applications, including cancer diagnosis and the detailed characterization of arterial wall biomechanics, both of which are based on the elastic properties of the tissue under investigation. We present OCE principles based on techniques associated with static and dynamic tissue excitation, and their corresponding elastogram image-reconstruction algorithms are reviewed. OCE techniques, including the development of intravascular- or catheter-based OCE, are in their early stages of development but show great promise for surgical oncology or intravascular cardiology applications.
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Affiliation(s)
- Cuiru Sun
- Department of Electrical and Computer Engineering, Biophotonics and Bioengineering Laboratory, Ryerson University, Toronto, Ontario M5B 2K3, Canada
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43
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Li Y, Snedeker JG. Elastography: modality-specific approaches, clinical applications, and research horizons. Skeletal Radiol 2011; 40:389-97. [PMID: 20352427 DOI: 10.1007/s00256-010-0918-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 02/24/2010] [Accepted: 02/24/2010] [Indexed: 02/02/2023]
Abstract
Manual palpation has been used for centuries to provide a relative indication of tissue health and disease. Engineers have sought to make these assessments increasingly quantitative and accessible within daily clinical practice. Since many of the developed techniques involve image-based quantification of tissue deformation in response to an applied force (i.e., "elastography"), such approaches fall squarely within the domain of the radiologist. While commercial elastography analysis software is becoming increasingly available for clinical use, the internal workings of these packages often remain a "black box," with limited guidance on how to usefully apply the methods toward a meaningful diagnosis. The purpose of the present review article is to introduce some important approaches to elastography that have been developed for the most widely used clinical imaging modalities (e.g., ultrasound, MRI), to provide a basic sense of the underlying physical principles, and to discuss both current and potential (musculoskeletal) applications. The article also seeks to provide a perspective on emerging approaches that are rapidly developing in the research laboratory (e.g., optical coherence tomography, fibered confocal microscopy), and which may eventually gain a clinical foothold.
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Affiliation(s)
- Yufei Li
- Department of Orthopaedics, University Hospital Balgrist, Forchstrasse 340, 8008, Zurich, Switzerland
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Kennedy BF, Liang X, Adie SG, Gerstmann DK, Quirk BC, Boppart SA, Sampson DD. In vivo three-dimensional optical coherence elastography. OPTICS EXPRESS 2011; 19:6623-34. [PMID: 21451690 PMCID: PMC3308196 DOI: 10.1364/oe.19.006623] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 02/28/2011] [Accepted: 03/15/2011] [Indexed: 05/18/2023]
Abstract
We present the first three-dimensional (3D) data sets recorded using optical coherence elastography (OCE). Uni-axial strain rate was measured on human skin in vivo using a spectral-domain optical coherence tomography (OCT) system providing >450 times higher line rate than previously reported for in vivo OCE imaging. Mechanical excitation was applied at a frequency of 125 Hz using a ring actuator sample arm with, for the first time in OCE measurements, a controlled static preload. We performed 3D-OCE, processed in 2D and displayed in 3D, on normal and hydrated skin and observed a more elastic response of the stratum corneum in the hydrated case.
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Affiliation(s)
- Brendan F Kennedy
- Optical + Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, The University of Western Australia, Crawley, Western Australia, Australia.
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45
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Abstract
Optical coherence tomography (OCT) is a non-destructive, non-invasive imaging modality conceptually similar to ultrasound imaging but uses near-infrared radiation rather than sound. It is attracting interest throughout the medical community as a tool for ophthalmic scanning (especially of the retina) and potentially for the diagnosis of many other illnesses such as epithelial cancer, connective tissue disorders, and atherosclerosis, as well as for surgical guidance. More recently, it has begun to be explored as a tool for the real-time monitoring of the growth and development of tissue-engineered products. OCT has certain unique advantages over traditional confocal microscopy; in particular, it can image to depths measured in hundreds of microns rather than tens of microns in intact biological tissues and with working distances in excess of 1 cm. Also it possesses label-free contrast for imaging ordered collagen (via birefringence), flow velocity and local shear-rate (via Doppler shifts), and sub-cellular structure (via coherent speckle contrast). The purpose of this short review is to introduce OCT technology and also give guidelines on its practical implementation to the interested researcher.
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Adie SG, Liang X, Kennedy BF, John R, Sampson DD, Boppart SA. Spectroscopic optical coherence elastography. OPTICS EXPRESS 2010; 18:25519-34. [PMID: 21164898 PMCID: PMC3319753 DOI: 10.1364/oe.18.025519] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 10/28/2010] [Accepted: 10/29/2010] [Indexed: 05/17/2023]
Abstract
We present an optical technique to image the frequency-dependent complex mechanical response of a viscoelastic sample. Three-dimensional hyperspectral data, comprising two-dimensional B-mode images and a third dimension corresponding to vibration frequency, were acquired from samples undergoing external mechanical excitation in the audio-frequency range. We describe the optical coherence tomography (OCT) signal when vibration is applied to a sample and detail the processing and acquisition techniques used to extract the local complex mechanical response from three-dimensional data that, due to a wide range of vibration frequencies, possess a wide range of sample velocities. We demonstrate frequency-dependent contrast of the displacement amplitude and phase of a silicone phantom containing inclusions of higher stiffness. Measurements of an ex vivo tumor margin demonstrate distinct spectra between adipose and tumor regions, and images of displacement amplitude and phase demonstrated spatially-resolved contrast. Contrast was also observed in displacement amplitude and phase images of a rat muscle sample. These results represent the first demonstration of mechanical spectroscopy based on B-mode OCT imaging. Spectroscopic optical coherence elastography (S-OCE) provides a high-resolution imaging capability for the detection of tissue pathologies that are characterized by a frequency-dependent viscoelastic response.
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Affiliation(s)
- Steven G. Adie
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 405 N. Mathews Avenue, Urbana, IL 61801,
USA
| | - Xing Liang
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 405 N. Mathews Avenue, Urbana, IL 61801,
USA
- Beckman Institute of Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. Mathews Avenue, Urbana, IL 61801,
USA
| | - Brendan F. Kennedy
- Optical and Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009,
Australia
| | - Renu John
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 405 N. Mathews Avenue, Urbana, IL 61801,
USA
| | - David D. Sampson
- Optical and Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009,
Australia
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009,
Australia
| | - Stephen A. Boppart
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 405 N. Mathews Avenue, Urbana, IL 61801,
USA
- Beckman Institute of Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. Mathews Avenue, Urbana, IL 61801,
USA
- Departments of Bioengineering, and Medicine, University of Illinois at Urbana-Champaign, 405 N. Mathews Avenue, Urbana, IL 61801,
USA
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LIANG XING, CRECEA VASILICA, BOPPART STEPHENA. DYNAMIC OPTICAL COHERENCE ELASTOGRAPHY: A REVIEW. JOURNAL OF INNOVATIVE OPTICAL HEALTH SCIENCES 2010; 3:221-233. [PMID: 22448192 PMCID: PMC3311124 DOI: 10.1142/s1793545810001180] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
With the development of optical coherence tomography, the application optical coherence elastography (OCE) has gained more and more attention in biomechanics for its unique features including micron-scale resolution, real-time processing, and non-invasive imaging. In this review, one group of OCE techniques, namely dynamic OCE, are introduced and discussed including external dynamic OCE mapping and imaging of ex vivo breast tumor, external dynamic OCE measurement of in vivo human skin, and internal dynamic OCE including acoustomotive OCE and magnetomotive OCE. These techniques overcame some of the major drawbacks of traditional static OCE, and broadened the OCE application fields. Driven by scientific needs to engineer new quantitative methods that utilize the high micron-scale resolution achievable with optics, results of biomechanical properties were obtained from biological tissues. The results suggest potential diagnostic and therapeutic clinical applications. Results from these studies also help our understanding of the relationship between biomechanical variations and functional tissue changes in biological systems.
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Affiliation(s)
- XING LIANG
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign Urbana, IL, 61801, USA
- Biophotonics Imaging Laboratory, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, 61801, USA
| | - VASILICA CRECEA
- Department of Physics, University of Illinois at Urbana-Champaign Urbana, IL, 61801, USA
- Biophotonics Imaging Laboratory, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, 61801, USA
| | - STEPHEN A. BOPPART
- Departments of Electrical and Computer Engineering, Bioengineering, and Internal Medicine, University of Illinois at Urbana-Champaign Urbana, IL, 61801, USA
- Biophotonics Imaging Laboratory, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, 61801, USA
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Liang X, Adie SG, John R, Boppart SA. Dynamic spectral-domain optical coherence elastography for tissue characterization. OPTICS EXPRESS 2010; 18:14183-90. [PMID: 20588552 PMCID: PMC3310369 DOI: 10.1364/oe.18.014183] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Revised: 06/08/2010] [Accepted: 06/14/2010] [Indexed: 05/18/2023]
Abstract
A dynamic spectral-domain optical coherence elastography (OCE) imaging technique is reported. In this technique, audio-frequency compressive vibrations are generated by a piezoelectric stack as external excitation, and strain rates in the sample are calculated and mapped quantitatively using phase-sensitive spectral-domain optical coherence tomography. At different driving frequencies, this technique provides contrast between sample regions with different mechanical properties, and thus is used to mechanically characterize tissue. We present images of a three-layer silicone tissue phantom and rat tumor tissue ex vivo, based on quantitative strain rate. Both acquisition speed and processing speed are improved dramatically compared with previous OCE imaging techniques. With high resolution, high acquisition speed, and the ability to characterize the mechanical properties of tissue, this OCE technique has potential use in non-destructive volumetric imaging and clinical applications.
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Affiliation(s)
- Xing Liang
- Department of Electrical and Computer Engineering, 405 N. Mathews Avenue, Urbana, IL 61801,
USA
- Beckman Institute of Advanced Science and Technology, 405 N. Mathews Avenue, Urbana, IL 61801,
USA
| | - Steven G. Adie
- Beckman Institute of Advanced Science and Technology, 405 N. Mathews Avenue, Urbana, IL 61801,
USA
| | - Renu John
- Beckman Institute of Advanced Science and Technology, 405 N. Mathews Avenue, Urbana, IL 61801,
USA
| | - Stephen A. Boppart
- Department of Electrical and Computer Engineering, 405 N. Mathews Avenue, Urbana, IL 61801,
USA
- Beckman Institute of Advanced Science and Technology, 405 N. Mathews Avenue, Urbana, IL 61801,
USA
- Departments of Bioengineering, and Medicine, University of Illinois at Urbana-Champaign, 405 N. Mathews Avenue, Urbana, IL 61801,
USA
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49
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Liang X, Boppart SA. Biomechanical properties of in vivo human skin from dynamic optical coherence elastography. IEEE Trans Biomed Eng 2010; 57:953-9. [PMID: 19822464 PMCID: PMC3699319 DOI: 10.1109/tbme.2009.2033464] [Citation(s) in RCA: 244] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dynamic optical coherence elastography is used to determine in vivo skin biomechanical properties based on mechanical surface wave propagation. Quantitative Young's moduli are measured on human skin from different sites, orientations, and frequencies. Skin thicknesses, including measurements from different layers, are also measured simultaneously. Experimental results show significant differences among measurements from different skin sites, between directions parallel and orthogonal to Langer's lines, and under different skin hydration states. Results also suggest surface waves with different driving frequencies represent skin biomechanical properties from different layers in depth. With features such as micrometer-scale resolution, noninvasive imaging, and real-time processing from the optical coherence tomography technology, this optical measurement technique has great potential for measuring skin biomechanical properties in dermatology.
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Affiliation(s)
- Xing Liang
- Department of Electrical and Computer Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
| | - Stephen A. Boppart
- Department of Electrical and Computer Engineering, Bioengineering, and Medicine, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
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50
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Oldenburg AL, Boppart SA. Resonant acoustic spectroscopy of soft tissues using embedded magnetomotive nanotransducers and optical coherence tomography. Phys Med Biol 2010; 55:1189-201. [PMID: 20124653 DOI: 10.1088/0031-9155/55/4/019] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
We present a new method for performing dynamic elastography of soft tissue samples. By sensing nanoscale displacements with optical coherence tomography, a chirped, modulated force is applied to acquire the mechanical spectrum of a tissue sample within a few seconds. This modulated force is applied via magnetic nanoparticles, named 'nanotransducers', which are diffused into the tissue, and which contribute negligible inertia to the soft tissue mechanical system. Using this novel system, we observed that excised tissues exhibit mechanical resonance modes which are well described by a linear damped harmonic oscillator. Results are validated by using cylindrical tissue phantoms of agarose in which resonant frequencies (30-400 Hz) are consistent with longitudinal modes and the sample boundary conditions. We furthermore show that the Young's modulus can be computed from their measured resonance frequencies, analogous to resonant ultrasound spectroscopy for stiff material analysis. Using this new technique, named magnetomotive resonant acoustic spectroscopy (MRAS), we monitored the relative stiffening of an excised rat liver during a chemical fixation process.
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Affiliation(s)
- Amy L Oldenburg
- Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana, IL 61801, USA
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