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Hajjarian Z, Nadkarni SK. Technological perspectives on laser speckle micro-rheology for cancer mechanobiology research. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-210119-PER. [PMID: 34549559 PMCID: PMC8455299 DOI: 10.1117/1.jbo.26.9.090601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 08/31/2021] [Indexed: 06/13/2023]
Abstract
SIGNIFICANCE The ability to measure the micro-mechanical properties of biological tissues and biomaterials is crucial for numerous fields of cancer research, including tumor mechanobiology, tumor-targeting drug delivery, and therapeutic development. AIM Our goal is to provide a renewed perspective on the mainstream techniques used for micro-mechanical evaluation of biological tissues and biomimetic scaffoldings. We specifically focus on portraying the outlook of laser speckle micro-rheology (LSM), a technology that quantifies the mechanical properties of biomaterials and tissues in a rapid, non-contact manner. APPROACH First, we briefly explain the motivation and significance of evaluating the tissue micro-mechanics in various fields of basic and translational cancer research and introduce the key concepts and quantitative metrics used to explain the mechanical properties of tissue. This is followed by reviewing the general active and passive themes of measuring micro-mechanics. Next, we focus on LSM and elaborate on the theoretical grounds and working principles of this technique. Then, the perspective for measuring the micro-mechanical properties via LSM is outlined. Finally, we draw an overview picture of LSM in cancer mechanobiology research. RESULTS With the continued emergence of new approaches for measuring the mechanical attributes of biological tissues, the field of micro-mechanical imaging is at its boom. As one of these competent innovations, LSM presents a tremendous potential for both technical maturation and prospective applications in cancer biomechanics and mechanobiology research. CONCLUSION By elaborating the current viewpoint of LSM, we expect to accelerate the expansion of this approach to new territories in both technological domains and applied fields. This renewed perspective on LSM may also serve as a road map for other micro-mechanical measurement concepts to be applied for answering mechanobiological questions.
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Affiliation(s)
- Zeinab Hajjarian
- Harvard Medical School, Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, Massachusetts, United States
| | - Seemantini K. Nadkarni
- Harvard Medical School, Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, Massachusetts, United States
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2
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Hajjarian Z, Toussaint JD, Guerrero JL, Nadkarni SK. In-vivo mechanical characterization of coronary atherosclerotic plaques in living swine using intravascular laser speckle imaging. BIOMEDICAL OPTICS EXPRESS 2021; 12:2064-2078. [PMID: 33996217 PMCID: PMC8086462 DOI: 10.1364/boe.418939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/07/2021] [Accepted: 02/09/2021] [Indexed: 05/13/2023]
Abstract
The ability to evaluate the viscoelastic properties of coronary arteries is crucial for identifying mechanically unstable atherosclerotic plaques. Here, we demonstrate for the first time in living swine, the capability of intravascular laser speckle imaging (ILSI) to measure an index of coronary plaque viscoelasticity, τ, using a human coronary to swine xenograft model. Cardiac motion effects are evaluated by comparing the EKG-non-gated τ ¯ N G , and EKG-gated τ ¯ G among different plaque types. Results show that both τ ¯ N G and τ ¯ G are significantly lower in necrotic-core plaques compared with stable lesions. Discrete-point pullback measurements demonstrate the capability of ILSI for rapid mechanical characterization of coronary segments under physiological conditions, in-vivo.
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Affiliation(s)
- Zeinab Hajjarian
- Wellman Center for Photomedicine, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02114, USA
- Authors contributed equally to the manuscript
| | - Jimmy D. Toussaint
- Wellman Center for Photomedicine, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02114, USA
- Authors contributed equally to the manuscript
| | - J. Luis Guerrero
- Surgical Cardiovascular Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Seemantini K. Nadkarni
- Wellman Center for Photomedicine, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02114, USA
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3
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Youssef D, Hassab-Elnaby S, El-Ghandoor H. Nanoscale quantitative surface roughness measurement of articular cartilage using second-order statistical-based biospeckle. PLoS One 2021; 16:e0246395. [PMID: 33513197 PMCID: PMC7845957 DOI: 10.1371/journal.pone.0246395] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 01/17/2021] [Indexed: 11/19/2022] Open
Abstract
Quantitative measurement of nanoscale surface roughness of articular cartilage tissue is significant to assess the surface topography for early treatment of osteoarthritis, the most common joint disease worldwide. Since it was not established by clinical diagnostic tools, the current studies have been suggesting the use of alternative diagnostic tools using pre-clinical methods. This study aims to measure the nanoscale surface roughness of articular cartilage tissue utilizing biospeckle which is used as a non-destructive and non-contact optical imaging technique. An experimental setup was implemented to capture biospeckle images from twelve cross-section areas of articular cartilage tissue gathered from bovine knee joints at 632 nm wavelength laser radiation. Then, to analyze the biospeckle image, a second-order statistical-based method was proposed through the combination of 308 highly correlated statistical features extracted from implemented gray-level co-occurrence matrices by employing principal component analysis. The result indicated that the measurement of the nanoscale surface roughness based on the first principal component only is able to provide accurate and precise quantitative measurement of early signs of articular cartilage degeneration up to 2500 nm.
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Affiliation(s)
- Doaa Youssef
- Department of Engineering Applications of Laser, National Institute of Laser Enhanced Science, Cairo University, Giza, Egypt
- * E-mail:
| | - Salah Hassab-Elnaby
- Department of Engineering Applications of Laser, National Institute of Laser Enhanced Science, Cairo University, Giza, Egypt
| | - Hatem El-Ghandoor
- Faculty of Science, Department of Physics, Ain Shams University, Cairo, Egypt
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Hajjarian Z, Nadkarni SK. Tutorial on laser speckle rheology: technology, applications, and opportunities. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-19. [PMID: 32358928 PMCID: PMC7195443 DOI: 10.1117/1.jbo.25.5.050801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 04/10/2020] [Indexed: 05/27/2023]
Abstract
SIGNIFICANCE The onset of several diseases is frequently marked with anomalous mechanical alteration of the affected tissue at the intersection of cells and their microenvironment. Therefore, mapping the micromechanical attributes of the tissues could enhance our understanding of the etiology of human disease, improve the diagnosis, and help stratify therapies that target these mechanical aberrations. AIM We review the tremendous opportunities offered through using optics for imaging the micromechanical properties, at length scales inaccessible to other modalities, in both basic research and clinical medicine. We specifically focus on laser speckle rheology (LSR), a technology that quantifies the mechanical properties of tissues in a rapid, noncontact manner. APPROACH In LSR, the shear viscoelastic modulus is measured from the time-variant speckle intensity fluctuations reflected off the tissue. The LSR technology is engineered and configured into several embodiments, including bench-top optical systems, endoscopes for minimally invasive procedures, portable point-of-care devices, and microscopes. RESULTS These technological nuances have primed the LSR for widespread applications in diagnosis and therapeutic monitoring, as demonstrated here, in cardiovascular disease, coagulation disorders, and tumor malignancies. CONCLUSION The fast-paced technological advancements, elaborated here, position the LSR as a competent candidate for many more exciting opportunities in basic research and medicine.
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Affiliation(s)
- Zeinab Hajjarian
- Massachusetts General Hospital, Harvard Medical School, Wellman Center for Photomedicine, Boston, Massachusetts, United States
| | - Seemantini K. Nadkarni
- Massachusetts General Hospital, Harvard Medical School, Wellman Center for Photomedicine, Boston, Massachusetts, United States
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5
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Larin KV, Scarcelli G, Yakovlev VV. Optical elastography and tissue biomechanics. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-9. [PMID: 31758675 PMCID: PMC6873628 DOI: 10.1117/1.jbo.24.11.110901] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 10/31/2019] [Indexed: 05/18/2023]
Abstract
Mechanical forces play an important role in the behavior and development of biological systems and disease at all spatial scales, from cells and their constituents to tissues and organs. Such forces have a profound influence on the health, structural integrity, and normal function of cells and organs. Accurate knowledge of cell and tissue biomechanical properties is essential to map the distribution of forces and mechanical cues in biological systems. Cell and tissue biomechanical properties are also known to be important on their own as indicators of health or diseases state. Hence, optical elastography and biomechanics methods can aid in the understanding and clinical diagnosis of a wide variety of diseases. We provide a brief overview and highlight of the Optical Elastography and Tissue Biomechanics VI conference, which took place in San Francisco, February 2 and 3, 2019, as a part of Photonics West symposium.
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Affiliation(s)
- Kirill V. Larin
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Giuliano Scarcelli
- University of Maryland, Department of Biomedical Engineering, College Park, Maryland, United States
| | - Vladislav V. Yakovlev
- Texas A&M University, Department of Biomedical Engineering, College Station, Texas, United States
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Yokoi N, Aizu Y, Uozumi J. Analysis of blood coagulation process based on fractality and dynamic characteristic of laser speckle pattern. JOURNAL OF BIOMEDICAL OPTICS 2018; 24:1-7. [PMID: 30569670 PMCID: PMC6975187 DOI: 10.1117/1.jbo.24.3.031018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 11/28/2018] [Indexed: 06/09/2023]
Abstract
The reflection and transmission of coherent light from a biological system can yield information about its condition. In the case of blood exposed to the air, there is a change in the properties of the speckle patterns observed in the coagulation process. This can be studied by means of the rate of temporal variation, the contrast, and also the fractality of patterns. The fractality of the speckle pattern can be investigated by a fractal dimension, which can quantify a level of the complexity of platelet aggregation structure and a fibrin network formed in the process of blood coagulation. In addition, dynamic characteristics of a movement in blood also contain information on the progress of the coagulation process. Fractality and dynamic characteristics are investigated simultaneously for speckle patterns observed in the coagulation process of stored horse blood. Experimental results show the feasibility of the proposed method for detecting hemolysis and formation of platelet aggregation structure and the fibrin network during the coagulation process.
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Affiliation(s)
- Naomichi Yokoi
- National Institute of Technology, Asahikawa College, Department of Mechanical Systems Engineering, Asahikawa, Japan
| | - Yoshihisa Aizu
- Muroran Institute of Technology, College of Design and Manufacturing Technology, Muroran, Japan
| | - Jun Uozumi
- Hokkai-Gakuen University, Department of Electronics and Information Engineering, Sapporo, Japan
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Wang J, Hosoda M, Tshikudi DM, Hajjarian Z, Nadkarni SK. Intraluminal laser speckle rheology using an omni-directional viewing catheter. BIOMEDICAL OPTICS EXPRESS 2017; 8:137-150. [PMID: 28101407 PMCID: PMC5231287 DOI: 10.1364/boe.8.000137] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/04/2016] [Accepted: 12/05/2016] [Indexed: 05/27/2023]
Abstract
A number of disease conditions in luminal organs are associated with alterations in tissue mechanical properties. Here, we report a new omni-directional viewing Laser Speckle Rheology (LSR) catheter for mapping the mechanical properties of luminal organs without the need for rotational motion. The LSR catheter incorporates multiple illumination fibers, an optical fiber bundle and a multi-faceted mirror to permit omni-directional viewing of the luminal wall. By retracting the catheter using a motor-drive assembly, cylindrical maps of tissue mechanical properties are reconstructed. Evaluation conducted in a test phantom with circumferentially-varying mechanical properties demonstrates the capability of the LSR catheter for the accurate mechanical assessment of luminal organs.
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Affiliation(s)
- Jing Wang
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, MA 02114, USA
- Authors contributed equally to this work
| | - Masaki Hosoda
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, MA 02114, USA
- Healthcare Optics Research Laboratory, Canon U.S.A., Inc., Cambridge, MA 02139, USA
- Authors contributed equally to this work
| | - Diane M. Tshikudi
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, MA 02114, USA
| | - Zeinab Hajjarian
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, MA 02114, USA
| | - Seemantini K. Nadkarni
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, MA 02114, USA
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8
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Laser Speckle Rheology for evaluating the viscoelastic properties of hydrogel scaffolds. Sci Rep 2016; 6:37949. [PMID: 27905494 PMCID: PMC5131361 DOI: 10.1038/srep37949] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 11/02/2016] [Indexed: 11/08/2022] Open
Abstract
Natural and synthetic hydrogel scaffolds exhibit distinct viscoelastic properties at various length scales and deformation rates. Laser Speckle Rheology (LSR) offers a novel, non-contact optical approach for evaluating the frequency-dependent viscoelastic properties of hydrogels. In LSR, a coherent laser beam illuminates the specimen and a high-speed camera acquires the time-varying speckle images. Cross-correlation analysis of frames returns the speckle intensity autocorrelation function, g2(t), from which the frequency-dependent viscoelastic modulus, G*(ω), is deduced. Here, we establish the capability of LSR for evaluating the viscoelastic properties of hydrogels over a large range of moduli, using conventional mechanical rheometry and atomic force microscopy (AFM)-based indentation as reference-standards. Results demonstrate a strong correlation between |G*(ω)| values measured by LSR and mechanical rheometry (r = 0.95, p < 10−9), and z-test analysis reports that moduli values measured by the two methods are identical (p > 0.08) over a large range (47 Pa – 36 kPa). In addition, |G*(ω)| values measured by LSR correlate well with indentation moduli, E, reported by AFM (r = 0.92, p < 10−7). Further, spatially-resolved moduli measurements in micro-patterned substrates demonstrate that LSR combines the strengths of conventional rheology and micro-indentation in assessing hydrogel viscoelastic properties at multiple frequencies and small length-scales.
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Regan C, Yang BY, Mayzel KC, Ramirez-San-Juan JC, Wilder-Smith P, Choi B. Fiber-based laser speckle imaging for the detection of pulsatile flow. Lasers Surg Med 2016. [PMID: 26202900 DOI: 10.1002/lsm.22370] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND AND OBJECTIVE In endodontics, a major diagnostic challenge is the accurate assessment of pulp status. In this study, we designed and characterized a fiber-based laser speckle imaging system to study pulsatile blood flow in the tooth. STUDY DESIGN/MATERIALS AND METHODS To take transilluminated laser speckle images of the teeth, we built a custom fiber-based probe. To assess our ability to detect changes in pulsatile flow, we performed in vitro and preliminary in vivo tests on tissue-simulating phantoms and human teeth. We imaged flow of intralipid in a glass microchannel at simulated heart rates ranging from 40 beats/minute (bpm) to 120 bpm (0.67-2.00 Hz). We also collected in vivo data from the upper front incisors of healthy subjects. From the measured raw speckle data, we calculated temporal speckle contrast versus time. With frequency-domain analysis, we identified the frequency components of the contrast waveforms. RESULTS With our approach, we observed in vitro the presence of pulsatile flow at different simulated heart rates. We characterized simulated heart rate with an accuracy of and >98%. In the in vivo proof-of-principle experiment, we measured heart rates of 69, 90, and 57 bpm, which agreed with measurements of subject heart rate taken with a wearable, commercial pulse oximeter. CONCLUSIONS We designed, built, and tested the performance of a dental imaging probe. Data from in vitro and in -vivo tests strongly suggest that this probe can detect the presence of pulsatile flow. LSI may enable endodontists to noninvasively assess pulpal vitality via direct measurement of blood flow.
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Affiliation(s)
- Caitlin Regan
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, California, 92612.,Department of Biomedical Engineering, University of California, Irvine, California, 92697
| | - Bruce Y Yang
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, California, 92612
| | - Kent C Mayzel
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, California, 92612.,Department of Biomedical Engineering, University of California, Irvine, California, 92697
| | - Julio C Ramirez-San-Juan
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, California, 92612.,Optics Department, Instituto Nacional de Astrofísica, Óptica y Electrónica, Puebla, México, 72840
| | - Petra Wilder-Smith
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, California, 92612.,Department of Surgery, University of California, Irvine Medical Center, Orange, California, 92868
| | - Bernard Choi
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, California, 92612.,Department of Biomedical Engineering, University of California, Irvine, California, 92697.,Department of Surgery, University of California, Irvine Medical Center, Orange, California, 92868.,Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California, Irvine, California, 92697
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10
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Hajjarian Z, Tripathi MM, Nadkarni SK. Optical Thromboelastography to evaluate whole blood coagulation. JOURNAL OF BIOPHOTONICS 2015; 8:372-81. [PMID: 24700701 PMCID: PMC4605542 DOI: 10.1002/jbio.201300197] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 03/07/2014] [Accepted: 03/15/2014] [Indexed: 05/12/2023]
Abstract
Measurement of blood viscoelasticity during clotting provides a direct metric of haemostatic conditions. Therefore, technologies that quantify blood viscoelasticity at the point-of-care are invaluable for diagnosing coagulopathies. We present a new approach, Optical Thromboelastography (OTEG) that measures the viscoelastic properties of coagulating blood by evaluating temporal laser speckle fluctuations, reflected from a few blood drops. During coagulation, platelet-fibrin clot formation restricts the mean square displacements (MSD) of scatterers and decelerates speckle fluctuations. Cross-correlation analysis of speckle frames provides the speckle intensity temporal autocorrelation, g2 (t), from which MSD is deduced and the viscoelastic modulus of blood is estimated. Our results demonstrate a close correspondence between blood viscoelasticity evaluated by OTEG and mechanical rheometry. Spatio-temporal speckle analyses yield 2-dimensional maps of clot viscoelasticity, enabling the identification of micro-clot formation at distinct rates in normal and coagulopathic specimens. These findings confirm the unique capability of OTEG for the rapid evaluation of patients' coagulation status and highlight the potential for point-of-care use.
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Affiliation(s)
- Zeinab Hajjarian
- Wellman Center For Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Markandey M Tripathi
- Wellman Center For Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Seemantini K Nadkarni
- Wellman Center For Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
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11
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Wang J, Nadkarni SK. The influence of optical fiber bundle parameters on the transmission of laser speckle patterns. OPTICS EXPRESS 2014; 22:8908-18. [PMID: 24787780 DOI: 10.1364/oe.22.008908] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Laser speckle imaging (LSI) techniques provide important functional information about tissue perfusion and mechanical properties. To perform LSI in vivo, laser speckle patterns are transmitted via optical fiber bundles incorporated within small-diameter endoscopes. Inter-fiber crosstalk due to mode coupling in fiber bundles can result in erroneous speckle statistics and therefore reduces the accuracy of LSI analysis. In this paper, we investigate the influence of multiple parameters that influence crosstalk between neighboring cores within optical fiber bundles and govern the modulation of transmitted laser speckle patterns. Our results show that in addition to large core-to-core separation, large refractive index contrast between core and cladding material, reduced number of propagating modes and variability in core size are essential parameters for accurate speckle pattern transmission to conduct endoscopic LSI.
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12
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Hajjarian Z, Nadkarni SK. Correction of optical absorption and scattering variations in Laser Speckle Rheology measurements. OPTICS EXPRESS 2014; 22:6349-61. [PMID: 24663983 PMCID: PMC4083052 DOI: 10.1364/oe.22.006349] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Laser Speckle Rheology (LSR) is an optical technique to evaluate the viscoelastic properties by analyzing the temporal fluctuations of backscattered speckle patterns. Variations of optical absorption and reduced scattering coefficients further modulate speckle fluctuations, posing a critical challenge for quantitative evaluation of viscoelasticity. We compare and contrast two different approaches applicable for correcting and isolating the collective influence of absorption and scattering, to accurately measure mechanical properties. Our results indicate that the numerical approach of Monte-Carlo ray tracing (MCRT) reliably compensates for any arbitrary optical variations. When scattering dominates absorption, yet absorption is non-negligible, diffusing wave spectroscopy (DWS) formalisms perform similar to MCRT, superseding other analytical compensation approaches such as Telegrapher equation. The computational convenience of DWS greatly simplifies the extraction of viscoelastic properties from LSR measurements in a number of chemical, industrial, and biomedical applications.
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Tripathi MM, Hajjarian Z, Van Cott EM, Nadkarni SK. Assessing blood coagulation status with laser speckle rheology. BIOMEDICAL OPTICS EXPRESS 2014; 5:817-31. [PMID: 24688816 PMCID: PMC3959840 DOI: 10.1364/boe.5.000817] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 12/30/2013] [Accepted: 01/02/2014] [Indexed: 05/23/2023]
Abstract
We have developed and investigated a novel optical approach, Laser Speckle Rheology (LSR), to evaluate a patient's coagulation status by measuring the viscoelastic properties of blood during coagulation. In LSR, a blood sample is illuminated with laser light and temporal speckle intensity fluctuations are measured using a high-speed CMOS camera. During blood coagulation, changes in the viscoelastic properties of the clot restrict Brownian displacements of light scattering centers within the sample, altering the rate of speckle intensity fluctuations. As a result, blood coagulation status can be measured by relating the time scale of speckle intensity fluctuations with clinically relevant coagulation metrics including clotting time and fibrinogen content. Our results report a close correlation between coagulation metrics measured using LSR and conventional coagulation results of activated partial thromboplastin time, prothrombin time and functional fibrinogen levels, creating the unique opportunity to evaluate a patient's coagulation status in real-time at the point of care.
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Affiliation(s)
- Markandey M. Tripathi
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Zeinab Hajjarian
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Elizabeth M. Van Cott
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02144, USA
| | - Seemantini K. Nadkarni
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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14
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Ramirez-San-Juan JC, Regan C, Coyotl-Ocelotl B, Choi B. Spatial versus temporal laser speckle contrast analyses in the presence of static optical scatterers. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:106009. [PMID: 25334006 PMCID: PMC4407671 DOI: 10.1117/1.jbo.19.10.106009] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/22/2014] [Indexed: 05/19/2023]
Abstract
Previously published data demonstrate that the temporal processing algorithm for laser speckle contrast imaging (LSCI) can improve the visibility of deep blood vessels and is less susceptible to static speckle artifacts when compared with the spatial algorithm. To the best of our knowledge, the extent to which the temporal algorithm can accurately predict the speckle contrast associated with flow in deep blood vessels has not been quantified. Here, we employed two phantom systems and imaging setups (epi-illumination and transillumination) to study the contrast predicted by the spatial and temporal algorithms in subsurface capillary tubes as a function of the camera exposure time and the actual flow speed. Our data with both imaging setups suggest that the contrast predicted by the temporal algorithm, and therefore the relative flow speed, is nearly independent of the degree of static optical scattering that contributes to the overall measured speckle pattern. Collectively, these results strongly suggest the potential of temporal LSCI at a single-exposure time to assess accurately the changes in blood flow even in the presence of substantial static optical scattering.
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Affiliation(s)
- Julio C Ramirez-San-Juan
- Instituto Nacional de Astrofisica, Optica y Electronica, Departamento de Optica, Luis Enrique Erro No. 1, Tonantzintla, Puebla 72840, MexicobUniversity of California, Irvine, Beckman Laser Institute and Medical Clinic, Department of Surgery, 1002 Health S
| | - Caitlin Regan
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Department of Surgery, 1002 Health Sciences Road East, Irvine, California 92612, United StatescUniversity of California, Irvine, Department of Biomedical Engineering, 3120 Natur
| | - Beatriz Coyotl-Ocelotl
- Instituto Nacional de Astrofisica, Optica y Electronica, Departamento de Optica, Luis Enrique Erro No. 1, Tonantzintla, Puebla 72840, Mexico
| | - Bernard Choi
- University of California, Irvine, Beckman Laser Institute and Medical Clinic, Department of Surgery, 1002 Health Sciences Road East, Irvine, California 92612, United StatescUniversity of California, Irvine, Department of Biomedical Engineering, 3120 Natur
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15
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Nadkarni SK. Optical measurement of arterial mechanical properties: from atherosclerotic plaque initiation to rupture. JOURNAL OF BIOMEDICAL OPTICS 2013; 18:121507. [PMID: 24296995 PMCID: PMC4696609 DOI: 10.1117/1.jbo.18.12.121507] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/09/2013] [Accepted: 10/10/2013] [Indexed: 05/19/2023]
Abstract
During the pathogenesis of coronary atherosclerosis, from lesion initiation to rupture, arterial mechanical properties are altered by a number of cellular, molecular, and hemodynamic processes. There is growing recognition that mechanical factors may actively drive vascular cell signaling and regulate atherosclerosis disease progression. In advanced plaques, the mechanical properties of the atheroma influence stress distributions in the fibrous cap and mediate plaque rupture resulting in acute coronary events. This review paper explores current optical technologies that provide information on the mechanical properties of arterial tissue to advance our understanding of the mechanical factors involved in atherosclerosis development leading to plaque rupture. The optical approaches discussed include optical microrheology and traction force microscopy that probe the mechanical behavior of single cell and extracellular matrix components, and intravascular imaging modalities including laser speckle rheology, optical coherence elastography, and polarization-sensitive optical coherence tomography to measure the mechanical properties of advanced coronary lesions. Given the wealth of information that these techniques can provide, optical imaging modalities are poised to play an increasingly significant role in elucidating the mechanical aspects of coronary atherosclerosis in the future.
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Affiliation(s)
- Seemantini K. Nadkarni
- Massachusetts General Hospital, Harvard Medical School, Wellman Center for Photomedicine, Boston, Massachusetts 02114
- Address all correspondence to: Seemantini K. Nadkarni, Massachusetts General Hospital, Harvard Medical School, Wellman Center for Photomedicine, Boston, Massachusetts 02114. Tel: (617)-724-1381; Fax: (617)-7264103; E-mail:
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Evaluation and correction for optical scattering variations in laser speckle rheology of biological fluids. PLoS One 2013; 8:e65014. [PMID: 23705028 PMCID: PMC3660338 DOI: 10.1371/journal.pone.0065014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 04/22/2013] [Indexed: 11/19/2022] Open
Abstract
Biological fluids fulfill key functionalities such as hydrating, protecting, and nourishing cells and tissues in various organ systems. They are capable of these versatile tasks owing to their distinct structural and viscoelastic properties. Characterizing the viscoelastic properties of bio-fluids is of pivotal importance for monitoring the development of certain pathologies as well as engineering synthetic replacements. Laser Speckle Rheology (LSR) is a novel optical technology that enables mechanical evaluation of tissue. In LSR, a coherent laser beam illuminates the tissue and temporal speckle intensity fluctuations are analyzed to evaluate mechanical properties. The rate of temporal speckle fluctuations is, however, influenced by both optical and mechanical properties of tissue. Therefore, in this paper, we develop and validate an approach to estimate and compensate for the contributions of light scattering to speckle dynamics and demonstrate the capability of LSR for the accurate extraction of viscoelastic moduli in phantom samples and biological fluids of varying optical and mechanical properties.
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Hajjarian Z, Nadkarni SK. Depth-resolved mapping of tissue mechanical properties using a novel optical approach. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2012; 2011:5742-5. [PMID: 22255644 DOI: 10.1109/iembs.2011.6091421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Progression of most diseases, such as atherosclerosis, cancer, neurodegenerative disease and osteoarthritis is accompanied with drastic changes in biomechanics of tissue. Hence, non-contact and non-invasive technologies for 3-dimensional mapping of tissue biomechanics are invaluable for diagnostic purposes. Laser speckle Microrheology (LSM) is developed in our lab to enable high resolution mechanical evaluation of tissue. To this end, the tissue sample is illuminated by a coherent and focused laser beam and the back-scattered laser speckle pattern is spatio-temporally processed to extract a color-map of τ, which is the decay time constant of intensity decorrelation at each pixel in the image plane. Time constant, τ, is proven to be closely correlated with tissue mechanical properties. In this paper we validate the theoretical basis for LSM technology and investigate the potential for acquiring depth-resolved information from a light-scattering point of view. The patch analysis approach is introduced and the inter-relation between τ, number of scattering events, and penetration depth is explored for each patch. Axial variation of τ is characterized for two sample arterial regions and in-depth changes of mechanical properties are characterized. Finally, the required corrective measures are discussed.
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Affiliation(s)
- Zeinab Hajjarian
- Wellman Center for Photomedicine, Harvard Medical School, 40 Blossom St, Boston, MA 02114, USA.
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Hajjarian Z, Nadkarni SK. Measurement of bulk mechanical properties of tissue using laser speckle rheology. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2012; 2011:5746-8. [PMID: 22255645 DOI: 10.1109/iembs.2011.6091422] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In virtually all tissues, disease progression is accompanied by changes in the mechanical properties. Laser speckle rheology (LSR) is a new technique we have developed to measure the mechanical properties of tissue. By illuminating the sample with coherent laser light and calculating the speckle intensity modulations from reflected laser speckle patterns, LSR calculates τ, the decay time constant of intensity decorrelation which is closely associated with tissue mechanical properties. In this paper we validate the use of LSR technology in measuring mechanical properties of tissue. LSR measurements of τ are performed on a variety of phantom and tissue samples and compared with the complex shear modulus G*, measured using a rheometer. In all cases, strong correlation is observed between τ and G* (r=0.95, p < 0.002). These results demonstrate the efficacy of LSR as a non-invasive and non-contact technology for mechanical evaluation of biological samples.
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Affiliation(s)
- Zeinab Hajjarian
- Wellman Center for Photomedicine, Harvard Medical School, 40 Blossom St, Boston, MA 02114, USA.
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Hajjarian Z, Nadkarni SK. Evaluating the viscoelastic properties of tissue from laser speckle fluctuations. Sci Rep 2012; 2:316. [PMID: 22428085 PMCID: PMC3306019 DOI: 10.1038/srep00316] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 02/27/2012] [Indexed: 12/29/2022] Open
Abstract
Most pathological conditions such as atherosclerosis, cancer, neurodegenerative, and orthopedic disorders are accompanied with alterations in tissue viscoelasticity. Laser Speckle Rheology (LSR) is a novel optical technology that provides the invaluable potential for mechanical assessment of tissue in situ. In LSR, the specimen is illuminated with coherent light and the time constant of speckle fluctuations, τ, is measured using a high speed camera. Prior work indicates that τ is closely correlated with tissue microstructure and composition. Here, we investigate the relationship between LSR measurements of τ and sample mechanical properties defined by the viscoelastic modulus, G*. Phantoms and tissue samples over a broad range of viscoelastic properties are evaluated using LSR and conventional mechanical testing. Results demonstrate a strong correlation between τ and |G*| for both phantom (r = 0.79, p <0.0001) and tissue (r = 0.88, p<0.0001) specimens, establishing the unique capability of LSR in characterizing tissue viscoelasticity.
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Affiliation(s)
- Zeinab Hajjarian
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School , Boston, MA
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Zhang H, Li P, Feng N, Qiu J, Li B, Luo W, Luo Q. Correcting the detrimental effects of nonuniform intensity distribution on fiber-transmitting laser speckle imaging of blood flow. OPTICS EXPRESS 2012; 20:508-517. [PMID: 22274372 DOI: 10.1364/oe.20.000508] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Laser speckle spatial contrast analysis (LSSCA) is superior to laser speckle temporal contrast analysis (LSTCA) in monitoring the fast change in blood flow due to its advantage of high temporal resolution. However, the application of LSSCA which is based on spatial statistics may be limited when there is nonuniform intensity distribution such as fiber-transmitting laser speckle imaging. In this study, we present a normalized laser speckle spatial contrast analysis (nLSSCA) to correct the detrimental effects of nonuniform intensity distribution on the spatial statistics. Through numerical simulation and phantom experiments, it is found that just ten frames of dynamic laser speckle images are sufficient for nLSSCA to achieve effective correction. Furthermore, nLSSCA has higher temporal resolution than LSTCA to respond the change in velocity. LSSCA, LSTCA and nLSSCA are all applied in the fiber-transmitting laser speckle imaging system to analyze the change of cortical blood flow (CBF) during cortical spreading depression (CSD) in rat cortex respectively, and the results suggest that nLSSCA can examine the change of CBF more accurately. For these advantages, nLSSCA could be a potential tool for fiber-transmitting/endoscopic laser speckle imaging.
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Affiliation(s)
- Hongyan Zhang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
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Suter MJ, Nadkarni SK, Weisz G, Tanaka A, Jaffer FA, Bouma BE, Tearney GJ. Intravascular optical imaging technology for investigating the coronary artery. JACC Cardiovasc Imaging 2011; 4:1022-39. [PMID: 21920342 PMCID: PMC3583353 DOI: 10.1016/j.jcmg.2011.03.020] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 03/04/2011] [Accepted: 03/14/2011] [Indexed: 12/14/2022]
Abstract
There is an ever-increasing demand for new imaging methods that can provide additional information about the coronary wall to better characterize and stratify high-risk plaques, and to guide interventional and pharmacologic management of patients with coronary artery disease. While there are a number of imaging modalities that facilitate the assessment of coronary artery pathology, this review paper focuses on intravascular optical imaging modalities that provide information on the microstructural, compositional, biochemical, biomechanical, and molecular features of coronary lesions and stents. The optical imaging modalities discussed include angioscopy, optical coherence tomography, polarization sensitive-optical coherence tomography, laser speckle imaging, near-infrared spectroscopy, time-resolved laser induced fluorescence spectroscopy, Raman spectroscopy, and near-infrared fluorescence molecular imaging. Given the wealth of information that these techniques can provide, optical imaging modalities are poised to play an increasingly significant role in the evaluation of the coronary artery in the future.
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Affiliation(s)
- Melissa J. Suter
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Pulmonary and Critical Care Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Seemantini K. Nadkarni
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Pulmonary and Critical Care Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Giora Weisz
- Center for Interventional Vascular Therapy, New York-Presbyterian Hospital, Columbia University, and Cardiovascular Research Foundation, New York, New York
| | - Atsushi Tanaka
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Farouc A. Jaffer
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Cardiovascular Research Center, Cardiology Division, and Center for Molecular Imaging Research, Massachusetts General Hospital, Harvard Medical School, Boston Massachusetts
| | - Brett E. Bouma
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts
| | - Guillermo J. Tearney
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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Hajjarian Z, Xi J, Jaffer FA, Tearney GJ, Nadkarni SK. Intravascular laser speckle imaging catheter for the mechanical evaluation of the arterial wall. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:026005. [PMID: 21361689 PMCID: PMC3056316 DOI: 10.1117/1.3533322] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Laser speckle imaging (LSI) is a novel technique for measuring the mechanical properties of atherosclerotic plaques. In LSI, the decorrelation time constant of speckle intensity fluctuations provides an index of viscoelasticity that is closely related to plaque microstructure and composition. Here, we demonstrate for the first time, the feasibility of conducting LSI in vivo using a prototype 1.5 mm (4.5 Fr) diameter intravascular catheter. Investigation of the catheter performance using human arterial samples ex vivo shows that plaque time constants measured by the LSI catheter correlate well with those measured using a free-space bulk optics system. To demonstrate LSI in vivo, the catheter is interfaced with a portable console for intravascular evaluation in the aorta of a living rabbit. Distinct differences in arterial time constants are identified at normal aortic and stented sites in vivo with intravascular LSI.
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Affiliation(s)
- Zeinab Hajjarian
- Massachusetts General Hospital, Wellman Center for Photomedicine, Harvard Medical School, Boston, Massachusetts 02114, USA
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Naramore WJ, Chou NY. Next wave of optical imaging-clinical applications of laser speckle. Biomed Instrum Technol 2010; 44:54-7. [PMID: 20374126 DOI: 10.2345/0899-8205-44.1.54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Villard JW, Paranjape AS, Victor DA, Feldman MD. Applications of optical coherence tomography in cardiovascular medicine, Part 2. J Nucl Cardiol 2009; 16:620-39. [PMID: 19479314 PMCID: PMC4352576 DOI: 10.1007/s12350-009-9100-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 05/06/2009] [Indexed: 02/07/2023]
Affiliation(s)
- Joseph W Villard
- Division of Cardiology, University of Texas Health Science Center in San Antonio and the South Texas Veterans Affairs Health System, Mail Code 7872, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA.
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