1
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Imenez Silva PH, Pepin M, Figurek A, Gutiérrez-Jiménez E, Bobot M, Iervolino A, Mattace-Raso F, Hoorn EJ, Bailey MA, Hénaut L, Nielsen R, Frische S, Trepiccione F, Hafez G, Altunkaynak HO, Endlich N, Unwin R, Capasso G, Pesic V, Massy Z, Wagner CA. Animal models to study cognitive impairment of chronic kidney disease. Am J Physiol Renal Physiol 2024; 326:F894-F916. [PMID: 38634137 DOI: 10.1152/ajprenal.00338.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 03/11/2024] [Accepted: 04/04/2024] [Indexed: 04/19/2024] Open
Abstract
Mild cognitive impairment (MCI) is common in people with chronic kidney disease (CKD), and its prevalence increases with progressive loss of kidney function. MCI is characterized by a decline in cognitive performance greater than expected for an individual age and education level but with minimal impairment of instrumental activities of daily living. Deterioration can affect one or several cognitive domains (attention, memory, executive functions, language, and perceptual motor or social cognition). Given the increasing prevalence of kidney disease, more and more people with CKD will also develop MCI causing an enormous disease burden for these individuals, their relatives, and society. However, the underlying pathomechanisms are poorly understood, and current therapies mostly aim at supporting patients in their daily lives. This illustrates the urgent need to elucidate the pathogenesis and potential therapeutic targets and test novel therapies in appropriate preclinical models. Here, we will outline the necessary criteria for experimental modeling of cognitive disorders in CKD. We discuss the use of mice, rats, and zebrafish as model systems and present valuable techniques through which kidney function and cognitive impairment can be assessed in this setting. Our objective is to enable researchers to overcome hurdles and accelerate preclinical research aimed at improving the therapy of people with CKD and MCI.
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Affiliation(s)
- Pedro H Imenez Silva
- Institute of Physiology, University of Zurich, Zurich, Switzerland
- Division of Nephrology and Transplantation, Department of Internal Medicine, Erasmus Medical Center, University Medical Center, Rotterdam, The Netherlands
| | - Marion Pepin
- Institut National de la Santé et de la Recherche Médicale U-1018 Centre de Recherche en Épidémiologie et Santé des Population, Équipe 5, Paris-Saclay University, Versailles Saint-Quentin-en-Yvelines University, Villejuif, France
- Department of Geriatrics, Centre Hospitalier Universitaire Ambroise Paré, Assistance Publique-Hôpitaux de Paris Université Paris-Saclay, Paris, France
| | - Andreja Figurek
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Eugenio Gutiérrez-Jiménez
- Center for Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Mickaël Bobot
- Centre de Néphrologie et Transplantation Rénale, Hôpital de la Conception, Assistance Publique-Hopitaux de Marseille, and INSERM 1263, Institut National de la Recherche Agronomique 1260, C2VN, Aix-Marseille Universitaire, Marseille, France
| | - Anna Iervolino
- Department of Translational Medical Sciences, University of Campania 'Luigi Vanvitelli,' Naples, Italy
| | - Francesco Mattace-Raso
- Division of Geriatrics, Department of Internal Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Ewout J Hoorn
- Division of Nephrology and Transplantation, Department of Internal Medicine, Erasmus Medical Center, University Medical Center, Rotterdam, The Netherlands
| | - Matthew A Bailey
- Edinburgh Kidney, Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, United Kingdom
| | - Lucie Hénaut
- UR UPJV 7517, Jules Verne University of Picardie, Amiens, France
| | - Rikke Nielsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Francesco Trepiccione
- Department of Translational Medical Sciences, University of Campania 'Luigi Vanvitelli,' Naples, Italy
| | - Gaye Hafez
- Department of Pharmacology, Faculty of Pharmacy, Altinbas University, Istanbul, Turkey
| | - Hande O Altunkaynak
- Department of Pharmacology, Gulhane Faculty of Pharmacy, University of Health Sciences, Istanbul, Turkey
| | - Nicole Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany
| | - Robert Unwin
- Department of Renal Medicine, Royal Free Hospital, University College London, London, United Kingdom
| | - Giovambattista Capasso
- Department of Translational Medical Sciences, University of Campania 'Luigi Vanvitelli,' Naples, Italy
- Biogem Research Institute, Ariano Irpino, Italy
| | - Vesna Pesic
- Department of Physiology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia
| | - Ziad Massy
- Centre for Research in Epidemiology and Population Health, INSERM UMRS 1018, Clinical Epidemiology Team, University Paris-Saclay, University Versailles-Saint Quentin, Villejuif, France
- Department of Nephrology, Centre Hospitalier Universitaire Ambroise Paré, Assistance Publique-Hôpitaux de Paris Université Paris-Saclay, Paris, France
| | - Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland
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2
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Liu J, Xu H, Gao S, Liu L, Qu J, Ohulchanskyy TY. Combining near infrared fluorescence and laser speckle imaging with optical tissue clearing for in vivo transcranial monitoring of cerebral blood vessels damaged by photodynamic nanoformulation. BIOMEDICAL OPTICS EXPRESS 2024; 15:924-937. [PMID: 38404313 PMCID: PMC10890862 DOI: 10.1364/boe.513820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/08/2024] [Accepted: 01/08/2024] [Indexed: 02/27/2024]
Abstract
In vivo near infrared (NIR) fluorescence imaging and laser speckle contrast imaging (LSCI) are emerging optical bioimaging modalities, which can provide information on blood vessels morphology, volume and the blood flow velocity. Optical tissue clearing (OTC) technique addresses a light scattering problem in optical bioimaging, which is imperative for the transcranial brain imaging. Herein, we report an approach combining NIR fluorescence and LSC microscopy imaging with OTC. A liposomal nanoformulation comprising NIR fluorescent dye ICG and photosensitizer BPD was synthesized and injected intravenously into mouse with OTC treated skull. Transcranial excitation of BPD in nanoliposomes resulted in the localized, irradiation dose dependent photodynamic damage of the brain blood vessels, which was manifested both in NIR fluorescence and LSC transcranial imaging, revealing changes in the vessels morphology, volume and the blood flow rate. The developed approach allows for bimodal imaging guided, localized vascular PDT of cancer and other diseases.
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Affiliation(s)
- Jiantao Liu
- Key Laboratory of Optoelectronic Devices
and Systems of Ministry of Education and Guangdong Province, College
of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Hao Xu
- Key Laboratory of Optoelectronic Devices
and Systems of Ministry of Education and Guangdong Province, College
of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Siqi Gao
- Key Laboratory of Optoelectronic Devices
and Systems of Ministry of Education and Guangdong Province, College
of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Liwei Liu
- Key Laboratory of Optoelectronic Devices
and Systems of Ministry of Education and Guangdong Province, College
of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Junle Qu
- Key Laboratory of Optoelectronic Devices
and Systems of Ministry of Education and Guangdong Province, College
of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
- Engineering Research Center of Optical
Instrument and System, Ministry of Education, Shanghai Key Lab of
Modern Optical System, School of Optical-Electrical and Computer
Engineering, University of Shanghai for Science and
Technology, Shanghai, China
| | - Tymish Y. Ohulchanskyy
- Key Laboratory of Optoelectronic Devices
and Systems of Ministry of Education and Guangdong Province, College
of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
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3
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Kim G, Park HS, Shin P, Eom T, Yoon JH, Jeong Y, Oh WY. Direct Blood Cell Flow Imaging in Microvascular Networks. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2302244. [PMID: 37309282 DOI: 10.1002/smll.202302244] [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: 03/16/2023] [Revised: 05/19/2023] [Indexed: 06/14/2023]
Abstract
Blood flow dynamics in microvascular networks are intimately related to the health of tissues and organs. While numerous imaging modalities and techniques have been developed to assess blood flow dynamics for various applications, their utilization has been hampered by limited imaging speed and indirect quantification of blood flow dynamics. Here, direct blood cell flow imaging (DBFI) is demonstrated that provides visualization of individual motions of blood cells over a field of 0.71 mm × 1.42 mm with a time resolution of 0.69 ms (1450 frames s-1 ) without using any exogenous agents. DBFI enables precise dynamic analysis of blood cell flow velocities and fluxes in various vessels over a large field, from capillaries to arteries and veins, with unprecedented time resolution. Three exemplary applications of DBFI, quantification of blood flow dynamics of 3D vascular networks, analysis of heartbeat induced blood flow dynamics, and analysis of blood flow dynamics of neurovascular coupling, illustrate the potential of this new imaging technology.
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Affiliation(s)
- Gyounghwan Kim
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Hyun-Sang Park
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Paul Shin
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Taeguk Eom
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Jin-Hui Yoon
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Yong Jeong
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Wang-Yuhl Oh
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
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4
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Shin P, Pian Q, Ishikawa H, Hamanaka G, Mandeville ET, Guo S, Fu B, Alfadhel M, Allu SR, Şencan-Eğilmez I, Li B, Ran C, Vinogradov SA, Ayata C, Lo E, Arai K, Devor A, Sakadžić S. Aerobic exercise reverses aging-induced depth-dependent decline in cerebral microcirculation. eLife 2023; 12:e86329. [PMID: 37402178 PMCID: PMC10319437 DOI: 10.7554/elife.86329] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 06/16/2023] [Indexed: 07/06/2023] Open
Abstract
Aging is a major risk factor for cognitive impairment. Aerobic exercise benefits brain function and may promote cognitive health in older adults. However, underlying biological mechanisms across cerebral gray and white matter are poorly understood. Selective vulnerability of the white matter to small vessel disease and a link between white matter health and cognitive function suggests a potential role for responses in deep cerebral microcirculation. Here, we tested whether aerobic exercise modulates cerebral microcirculatory changes induced by aging. To this end, we carried out a comprehensive quantitative examination of changes in cerebral microvascular physiology in cortical gray and subcortical white matter in mice (3-6 vs. 19-21 months old), and asked whether and how exercise may rescue age-induced deficits. In the sedentary group, aging caused a more severe decline in cerebral microvascular perfusion and oxygenation in deep (infragranular) cortical layers and subcortical white matter compared with superficial (supragranular) cortical layers. Five months of voluntary aerobic exercise partly renormalized microvascular perfusion and oxygenation in aged mice in a depth-dependent manner, and brought these spatial distributions closer to those of young adult sedentary mice. These microcirculatory effects were accompanied by an improvement in cognitive function. Our work demonstrates the selective vulnerability of the deep cortex and subcortical white matter to aging-induced decline in microcirculation, as well as the responsiveness of these regions to aerobic exercise.
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Affiliation(s)
- Paul Shin
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Qi Pian
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Hidehiro Ishikawa
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Gen Hamanaka
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Emiri T Mandeville
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Shuzhen Guo
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Buyin Fu
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Mohammed Alfadhel
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Department of Bioengineering, Northeastern University, Boston, United States
| | - Srinivasa Rao Allu
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States
- Department of Chemistry, University of Pennsylvania, Philadelphia, United States
| | - Ikbal Şencan-Eğilmez
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Biophotonics Research Center, Mallinckrodt Institute of Radiology, Department of Radiology, Washington University School of Medicine, St. Louis, United States
| | - Baoqiang Li
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Chongzhao Ran
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Sergei A Vinogradov
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States
- Department of Chemistry, University of Pennsylvania, Philadelphia, United States
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Stroke Service, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Eng Lo
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Ken Arai
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Anna Devor
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Department of Biomedical Engineering, Boston University, Boston, United States
| | - Sava Sakadžić
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
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5
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Walek KW, Stefan S, Lee JH, Puttigampala P, Kim AH, Park SW, Marchand PJ, Lesage F, Liu T, Huang YWA, Boas DA, Moore C, Lee J. Near-lifespan longitudinal tracking of brain microvascular morphology, topology, and flow in male mice. Nat Commun 2023; 14:2982. [PMID: 37221202 DOI: 10.1038/s41467-023-38609-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/09/2023] [Indexed: 05/25/2023] Open
Abstract
In age-related neurodegenerative diseases, pathology often develops slowly across the lifespan. As one example, in diseases such as Alzheimer's, vascular decline is believed to onset decades ahead of symptomology. However, challenges inherent in current microscopic methods make longitudinal tracking of such vascular decline difficult. Here, we describe a suite of methods for measuring brain vascular dynamics and anatomy in mice for over seven months in the same field of view. This approach is enabled by advances in optical coherence tomography (OCT) and image processing algorithms including deep learning. These integrated methods enabled us to simultaneously monitor distinct vascular properties spanning morphology, topology, and function of the microvasculature across all scales: large pial vessels, penetrating cortical vessels, and capillaries. We have demonstrated this technical capability in wild-type and 3xTg male mice. The capability will allow comprehensive and longitudinal study of a broad range of progressive vascular diseases, and normal aging, in key model systems.
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Affiliation(s)
- Konrad W Walek
- Warren Alpert Medical School, Brown University, Providence, RI, 02912, USA
| | - Sabina Stefan
- School of Engineering, Brown University, Providence, RI, 02912, USA
| | - Jang-Hoon Lee
- School of Engineering, Brown University, Providence, RI, 02912, USA
| | | | - Anna H Kim
- Department of Neuroscience, Brown University, Providence, RI, 02912, USA
| | - Seong Wook Park
- Department of Neuroscience, Brown University, Providence, RI, 02912, USA
| | - Paul J Marchand
- Department of Electrical Engineering, École Polytechnique de Montréal, Montréal, QC, H3T 1J4, Canada
| | - Frederic Lesage
- Department of Electrical Engineering, École Polytechnique de Montréal, Montréal, QC, H3T 1J4, Canada
| | - Tao Liu
- Department of Biostatistics, Brown University School of Public Health, Providence, RI, 02912, USA
| | - Yu-Wen Alvin Huang
- Warren Alpert Medical School, Brown University, Providence, RI, 02912, USA
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02912, USA
- Carney Institute for Brain Science, Brown University, Providence, RI, 02912, USA
| | - David A Boas
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, USA
| | - Christopher Moore
- Department of Neuroscience, Brown University, Providence, RI, 02912, USA
- Carney Institute for Brain Science, Brown University, Providence, RI, 02912, USA
| | - Jonghwan Lee
- School of Engineering, Brown University, Providence, RI, 02912, USA.
- Carney Institute for Brain Science, Brown University, Providence, RI, 02912, USA.
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6
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Lee JH, Stefan S, Walek K, Nie J, Min K, Yang TD, Lee J. Investigating the correlation between early vascular alterations and cognitive impairment in Alzheimer's disease in mice with SD-OCT. BIOMEDICAL OPTICS EXPRESS 2023; 14:1494-1508. [PMID: 37078054 PMCID: PMC10110305 DOI: 10.1364/boe.481826] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 02/25/2023] [Accepted: 03/01/2023] [Indexed: 05/03/2023]
Abstract
Vascular alterations have recently gained some attention with their strong association with Alzheimer's disease (AD). We conducted a label-free in vivo optical coherence tomography (OCT) longitudinal imaging using an AD mouse model. We achieved the tracking of the same individual vessels over time and conducted an in-depth analysis of temporal dynamics in vasculature and vasodynamics using OCT angiography and Doppler-OCT. The AD group showed an exponential decay in both vessel diameter and blood flow change with the critical timepoint before 20 weeks of age, which precedes cognitive decline observed at 40 weeks of age. Interestingly, for the AD group, the diameter change showed the dominance in arterioles over venules, but no such influence was found in blood flow change. Conversely, three mice groups with early vasodilatory intervention did not show any significant change in both vascular integrity and cognitive function compared to the wild-type group. We found early vascular alterations and confirmed their correlation with cognitive impairment in AD.
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Affiliation(s)
- Jang-Hoon Lee
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, Rhode Island 02912, USA
| | - Sabina Stefan
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA
| | - Konrad Walek
- Warren Alpert Medical School of Brown University, Providence, Rhode Island 02903, USA
| | - Jiarui Nie
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, Rhode Island 02912, USA
| | - Kyounghee Min
- University of Massachusetts Chan Medical School, Worcester, Massachusetts 01655, USA
| | - Taeseok Daniel Yang
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, Rhode Island 02912, USA
- Department of Bioengineering, Korea University, Seoul 02841, Republic of Korea
| | - Jonghwan Lee
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, Rhode Island 02912, USA
- Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, USA
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7
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Shin P, Pian Q, Ishikawa H, Hamanaka G, Mandeville ET, Shuzhen G, Buyin F, Alfadhel M, Allu SR, Şencan-Eğilmez I, Li B, Ran C, Vinogradov SA, Ayata C, Lo EH, Arai K, Devor A, Sakadžić S. Aerobic exercise reverses aging-induced depth-dependent decline in cerebral microcirculation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.12.528244. [PMID: 36824939 PMCID: PMC9949059 DOI: 10.1101/2023.02.12.528244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
Aging is a major risk factor for cognitive impairment. Aerobic exercise benefits brain function and may promote cognitive health in older adults. However, underlying biological mechanisms across cerebral gray and white matter are poorly understood. Selective vulnerability of the white matter to small vessel disease and a link between white matter health and cognitive function suggests a potential role for responses in deep cerebral microcirculation. Here, we tested whether aerobic exercise modulates cerebral microcirculatory changes induced by aging. To this end, we carried out a comprehensive quantitative examination of changes in cerebral microvascular physiology in cortical gray and subcortical white matter in mice (3-6 vs. 19-21 months old), and asked whether and how exercise may rescue age-induced deficits. In the sedentary group, aging caused a more severe decline in cerebral microvascular perfusion and oxygenation in deep (infragranular) cortical layers and subcortical white matter compared with superficial (supragranular) cortical layers. Five months of voluntary aerobic exercise partly renormalized microvascular perfusion and oxygenation in aged mice in a depth-dependent manner, and brought these spatial distributions closer to those of young adult sedentary mice. These microcirculatory effects were accompanied by an improvement in cognitive function. Our work demonstrates the selective vulnerability of the deep cortex and subcortical white matter to aging-induced decline in microcirculation, as well as the responsiveness of these regions to aerobic exercise.
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Affiliation(s)
- Paul Shin
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
- Corresponding author:
| | - Qi Pian
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Hidehiro Ishikawa
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Gen Hamanaka
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Emiri T Mandeville
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Guo Shuzhen
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Fu Buyin
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Mohammed Alfadhel
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
- Department of Bioengineering, Northeastern University, Boston, MA, USA
| | - Srinivasa Rao Allu
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, USA
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
| | - Ikbal Şencan-Eğilmez
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
- Biophotonics Research Center, Mallinckrodt Institute of Radiology, Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Baoqiang Li
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China
| | - Chongzhao Ran
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Sergei A Vinogradov
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, USA
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
- Stroke Service, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Eng H Lo
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Ken Arai
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Anna Devor
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
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8
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Retinal blood flow reversal quantitatively monitored in out-of-plane vessels with laser Doppler holography. Sci Rep 2021; 11:17828. [PMID: 34497299 PMCID: PMC8426375 DOI: 10.1038/s41598-021-96877-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 08/05/2021] [Indexed: 12/29/2022] Open
Abstract
Laser Doppler holography is a planar blood flow imaging technique recently introduced in ophthalmology to image human retinal and choroidal blood flow non-invasively. Here we present a digital method based on the Doppler spectrum asymmetry that reveals the local direction of blood flow with respect to the optical axis in out-of-plane vessels. This directional information is overlaid on standard grayscale blood flow images to depict flow moving towards the camera in red and flow moving away from the camera in blue, as in ultrasound color Doppler imaging. We show that thanks to the strong contribution of backscattering to the Doppler spectrum in out-of-plane vessels, the local axial direction of blood flow can be revealed with a high temporal resolution, which enables us to evidence pathological blood flow reversals. We also demonstrate the use of optical Doppler spectrograms to quantitatively monitor retinal blood flow reversals.
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9
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Celaya-Alcala JT, Lee GV, Smith AF, Li B, Sakadžić S, Boas DA, Secomb TW. Simulation of oxygen transport and estimation of tissue perfusion in extensive microvascular networks: Application to cerebral cortex. J Cereb Blood Flow Metab 2021; 41:656-669. [PMID: 32501155 PMCID: PMC7922761 DOI: 10.1177/0271678x20927100] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 01/23/2020] [Accepted: 02/15/2020] [Indexed: 12/13/2022]
Abstract
Advanced imaging techniques have made available extensive three-dimensional microvascular network structures. Simulation of oxygen transport by such networks requires information on blood flow rates and oxygen levels in vessels crossing boundaries of the imaged region, which is difficult to obtain experimentally. Here, a computational method is presented for estimating blood flow rates, oxygen levels, tissue perfusion and oxygen extraction, based on incomplete boundary conditions. Flow rates in all segments are estimated using a previously published method. Vessels crossing the region boundary are classified as arterioles, capillaries or venules. Oxygen levels in inflowing capillaries are assigned based on values in outflowing capillaries, and similarly for venules. Convective and diffusive oxygen transport is simulated. Contributions of each vessel to perfusion are computed in proportion to the decline in oxygen concentration along that vessel. For a vascular network in the mouse cerebral cortex, predicted tissue oxygen levels show a broad distribution, with 99% of tissue in the range of 20 to 80 mmHg under reference conditions, and steep gradients near arterioles. Perfusion and extraction estimates are consistent with experimental values. A 30% reduction in perfusion or a 30% increase in oxygen demand, relative to reference levels, is predicted to result in tissue hypoxia.
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Affiliation(s)
| | - Grace V Lee
- Program in Applied Mathematics,
University of Arizona, Tucson, AZ, USA
| | - Amy F Smith
- Department of Physiology, University
of Arizona, Tucson, AZ, USA
| | - Bohan Li
- Department of Mathematics,
University of Arizona, Tucson, AZ, USA
| | - Sava Sakadžić
- Athinoula A. Martinos Center for
Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School,
Boston, MA, USA
| | - David A Boas
- Athinoula A. Martinos Center for
Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School,
Boston, MA, USA
- Department of Biomedical
Engineering, Boston University, Boston, MA, USA
| | - Timothy W Secomb
- Department of Mathematics,
University of Arizona, Tucson, AZ, USA
- Program in Applied Mathematics,
University of Arizona, Tucson, AZ, USA
- Department of Physiology, University
of Arizona, Tucson, AZ, USA
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10
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Validation of red blood cell flux and velocity estimations based on optical coherence tomography intensity fluctuations. Sci Rep 2020; 10:19584. [PMID: 33177606 PMCID: PMC7658245 DOI: 10.1038/s41598-020-76774-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 11/02/2020] [Indexed: 01/03/2023] Open
Abstract
We present a validation of red blood cell flux and speed measurements based on the passage of erythrocytes through the OCT’s focal volume. We compare the performance of the so-called RBC-passage OCT technique to co-localized and simultaneously acquired two-photon excitation fluorescence microscopy (TPEF) measurements. Using concurrent multi-modal imaging, we show that fluctuations in the OCT signal display highly similar features to TPEF time traces. Furthermore, we demonstrate an overall difference in RBC flux and speed of 2.5 ± 3.27 RBC/s and 0.12 ± 0.67 mm/s (mean ± S.D.), compared to TPEF. The analysis also revealed that the OCT RBC flux estimation is most accurate between 20 RBC/s to 60 RBC/s, and is severely underestimated at fluxes beyond 80 RBC/s. Lastly, our analysis shows that the RBC speed estimations increase in accuracy as the speed decreases, reaching a difference of 0.16 ± 0.25 mm/s within the 0–0.5 mm/s speed range.
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11
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Ahn SJ, Ruiz-Uribe NE, Li B, Porter J, Sakadzic S, Schaffer CB. Label-free assessment of hemodynamics in individual cortical brain vessels using third harmonic generation microscopy. BIOMEDICAL OPTICS EXPRESS 2020; 11:2665-2678. [PMID: 32499951 PMCID: PMC7249811 DOI: 10.1364/boe.385848] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 04/07/2020] [Accepted: 04/15/2020] [Indexed: 05/04/2023]
Abstract
We show that third harmonic generation (THG) microscopy using a 1-MHz train of 1,300-nm femtosecond duration laser pulses enabled visualization of the structure and quantification of flow speed in the cortical microvascular network of mice to a depth of > 1 mm. Simultaneous three-photon imaging of an intravascular fluorescent tracer enabled us to quantify the cell free layer thickness. Using the label-free imaging capability of THG, we measured flow speed in different types of vessels with and without the presence of an intravascular tracer conjugated to a high molecular weight dextran (2 MDa FITC-dextran, 5% w/v in saline, 100 µl). We found a ∼20% decrease in flow speeds in arterioles and venules due to the dextran-conjugated FITC, which we confirmed with Doppler optical coherence tomography. Capillary flow speeds did not change, although we saw a ∼7% decrease in red blood cell flux with dextran-conjugated FITC injection.
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Affiliation(s)
- Sung Ji Ahn
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14850, USA
| | - Nancy E. Ruiz-Uribe
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14850, USA
| | - Baoqiang Li
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Jason Porter
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Sava Sakadzic
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Chris B. Schaffer
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14850, USA
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12
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Shin P, Choi W, Joo J, Oh WY. Quantitative hemodynamic analysis of cerebral blood flow and neurovascular coupling using optical coherence tomography angiography. J Cereb Blood Flow Metab 2019; 39:1983-1994. [PMID: 29757059 PMCID: PMC6775585 DOI: 10.1177/0271678x18773432] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Functional hyperemia in the rat cortex was investigated using high-speed optical coherence tomography (OCT) angiography and Doppler OCT. OCT angiography (OCTA) was performed to image the hemodynamic stimulus-response over a wide field of view. Temporal changes in vessel diameters in different vessel compartments, which were determined as the diameters of erythrocyte flows in OCT angiograms, were measured in order to monitor localized hemodynamic changes. Our results showed that the dilation of arterioles at the site of activation was accompanied by the dilation of upstream arteries. Relatively negligible dilation was observed in veins. An increase in the OCTA signal was observed during stimulus in multiple capillaries, which may imply that capillary blood flow increases as a result of the expanded arterial blood volume. These results agree with previous observations using two-photon laser scanning microscopy (TPLSM). Doppler OCT was performed to quantitatively measure stimulus-induced blood flow response in pial arteries. The measurement showed small but clear hemodynamic response in upstream arteries with diameters exceeding 100 μm. Our results demonstrate the potential of OCTA and Doppler OCT for the investigation of neurovascular coupling in small animal models.
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Affiliation(s)
- Paul Shin
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.,KI for Health Science and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - WooJhon Choi
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - JongYoon Joo
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.,KI for Health Science and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Wang-Yuhl Oh
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.,KI for Health Science and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
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13
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Erdener ŞE, Tang J, Sajjadi A, Kılıç K, Kura S, Schaffer CB, Boas DA. Spatio-temporal dynamics of cerebral capillary segments with stalling red blood cells. J Cereb Blood Flow Metab 2019; 39:886-900. [PMID: 29168661 PMCID: PMC6501506 DOI: 10.1177/0271678x17743877] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Optical coherence tomography (OCT) allows label-free imaging of red blood cell (RBC) flux within capillaries with high spatio-temporal resolution. In this study, we utilized time-series OCT-angiography to demonstrate interruptions in capillary RBC flux in mouse brain in vivo. We noticed ∼7.5% of ∼200 capillaries had at least one stall in awake mice with chronic windows during a 9-min recording. At any instant, ∼0.45% of capillaries were stalled. Average stall duration was ∼15 s but could last over 1 min. Stalls were more frequent and longer lasting in acute window preparations. Further, isoflurane anesthesia in chronic preparations caused an increase in the number of stalls. In repeated imaging, the same segments had a tendency to stall again over a period of one month. In awake animals, functional stimulation decreased the observance of stalling events. Stalling segments were located distally, away from the first couple of arteriolar-side capillary branches and their average RBC and plasma velocities were lower than nonstalling capillaries within the same region. This first systematic analysis of capillary RBC stalls in the brain, enabled by rapid and continuous volumetric imaging of capillaries with OCT-angiography, will lead to future investigations of the potential role of stalling events in cerebral pathologies.
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Affiliation(s)
- Şefik Evren Erdener
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Jianbo Tang
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Amir Sajjadi
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Kıvılcım Kılıç
- 2 Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sreekanth Kura
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Chris B Schaffer
- 3 Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - David A Boas
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.,2 Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
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14
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Wartak A, Beer F, Desissaire S, Baumann B, Pircher M, Hitzenberger CK. Investigating spontaneous retinal venous pulsation using Doppler optical coherence tomography. Sci Rep 2019; 9:4237. [PMID: 30862956 PMCID: PMC6414623 DOI: 10.1038/s41598-019-40961-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 02/26/2019] [Indexed: 12/26/2022] Open
Abstract
We demonstrate the advantages of optical coherence tomography (OCT) imaging for investigation of spontaneous retinal venous pulsation (SRVP). The pulsatile changes in venous vessel caliber are analyzed qualitatively and quantitatively using conventional intensity-based OCT as well as the functional extension Doppler OCT (DOCT). Single-channel and double-channel line scanning protocols of our multi-channel OCT prototype are employed to investigate venous pulsatile caliber oscillations as well as venous flow pulsatility in the eyes of healthy volunteers. A comparison to recordings of scanning laser ophthalmoscopy (SLO) – a standard en-face imaging modality for evaluation of SRVP – is provided, emphasizing the advantages of tomographic image acquisition. To the best of our knowledge, this is the first quantitative time-resolved investigation of SRVP and associated retinal perfusion characteristics using OCT.
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Affiliation(s)
- Andreas Wartak
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, 1090, Austria.
| | - Florian Beer
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, 1090, Austria
| | - Sylvia Desissaire
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, 1090, Austria
| | - Bernhard Baumann
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, 1090, Austria
| | - Michael Pircher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, 1090, Austria
| | - Christoph K Hitzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, 1090, Austria
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15
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In vivo imaging for neurovascular disease research. Arch Pharm Res 2019; 42:263-273. [PMID: 30756309 DOI: 10.1007/s12272-019-01128-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 01/29/2019] [Indexed: 01/10/2023]
Abstract
Connections between various cell types in the brain enable cognitive function. The neurovascular unit is a structure composed of different cell types that regulate neurovascular coupling, blood-brain barrier permeability, and other interactions with peripheral systems. The relationship among the components of the neurovascular unit is complex and difficult to study without the use of in vivo neurovascular disease imaging. In this review, we introduce principles and examples of various in vivo optical imaging techniques including laser Doppler flowmetry, laser speckle contrast imaging, intrinsic optical signal imaging, optical coherence tomography, and two-photon microscopy. Furthermore, we introduce recent advances of in vivo imaging and future directions for promoting neurovascular disease research.
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16
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Akif A, Walek K, Polucha C, Lee J. Doppler OCT clutter rejection using variance minimization and offset extrapolation. BIOMEDICAL OPTICS EXPRESS 2018; 9:5340-5352. [PMID: 30460132 PMCID: PMC6238902 DOI: 10.1364/boe.9.005340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/05/2018] [Accepted: 10/05/2018] [Indexed: 05/02/2023]
Abstract
Doppler optical coherence tomography (OCT) is widely used for high-resolution mapping of flow velocities and is based on analysis of temporal changes in the phase of an OCT signal (i.e., how fast the OCT signal rotates in the complex plane). Determination of the rate of phase change or rotation speed critically depends on the center of rotation. Here, we demonstrate the bias in high-pass filtering, the current widely used method to determine the center of rotation, and propose two advanced methods for Doppler OCT clutter rejection. The bias in the high-pass filtering method becomes increasingly significant with lower velocities or larger signal noise. Two novel methods based on variance minimization and offset extrapolation can potentially reduce this bias and thereby improve the accuracy of Doppler OCT measurements of flow velocities, even for low-velocity and/or high-noise signals. The two novel methods and the current standard method (high-pass filtering) have been tested in combination with several currently used velocity measurement algorithms: Kasai, autocorrelation function fitting, and maximum likelihood estimation. The newly proposed methods are shown to improve the accuracy in both the center of rotation and resultant velocity by up to 60 percentage points and reduce the flow conservation error by 30% when applied to in vivo cerebral blood flow imaging of the rodent brain cortex.
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Affiliation(s)
- Adil Akif
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI 02906, USA
| | - Konrad Walek
- Department of Neuroscience, Brown University, Providence, RI 02906, USA
- Warren A. Alpert Medical School, Brown University, Providence, RI 02906, USA
| | - Collin Polucha
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI 02906, USA
| | - Jonghwan Lee
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI 02906, USA
- Carney Institute for Brain Science, Brown University, Providence, RI 02906, USA
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17
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Marchand PJ, Szlag D, Extermann J, Bouwens A, Nguyen D, Rudin M, Lasser T. Imaging of cortical structures and microvasculature using extended-focus optical coherence tomography at 1.3 μm. OPTICS LETTERS 2018; 43:1782-1785. [PMID: 29652363 DOI: 10.1364/ol.43.001782] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 03/16/2018] [Indexed: 06/08/2023]
Abstract
Extended-focus optical coherence tomography (xf-OCT) is a variant of optical coherence tomography (OCT) wherein the illumination and/or detection modes are engineered to provide a constant diffractionless lateral resolution over an extended depth of field (typically 3 to 10× the Rayleigh range). xf-OCT systems operating at 800 nm have been devised and used in the past to image brain structures at high-resolution in vivo, but are limited to ∼500 μm in penetration depth due to their short illumination wavelength. Here we present an xf-OCT system optimized to an image deeper within the cortex by using a longer illumination central wavelength of 1310 nm. The system offers a lateral resolution of 3 and 6.5 μm, over a depth of 900 μm and >1.5 mm using a 10× and 5× objective, respectively, in air. We characterize the system's resolution using microbeads embedded in PDMS and demonstrate its capabilities by imaging the cortical structure and microvasculature in anesthetized mice to a depth of ∼0.8 mm. Finally, we illustrate the difference in penetration depths obtainable with the new system and an xf-OCT system operating at 800 nm.
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18
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Marchand PJ, Szlag D, Bouwens A, Lasser T. In vivo high-resolution cortical imaging with extended-focus optical coherence microscopy in the visible-NIR wavelength range. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-7. [PMID: 29575831 DOI: 10.1117/1.jbo.23.3.036012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 03/07/2018] [Indexed: 05/10/2023]
Abstract
Visible light optical coherence tomography has shown great interest in recent years for spectroscopic and high-resolution retinal and cerebral imaging. Here, we present an extended-focus optical coherence microscopy system operating from the visible to the near-infrared wavelength range for high axial and lateral resolution imaging of cortical structures in vivo. The system exploits an ultrabroad illumination spectrum centered in the visible wavelength range (λc = 650 nm, Δλ ∼ 250 nm) offering a submicron axial resolution (∼0.85 μm in water) and an extended-focus configuration providing a high lateral resolution of ∼1.4 μm maintained over ∼150 μm in depth in water. The system's axial and lateral resolution are first characterized using phantoms, and its imaging performance is then demonstrated by imaging the vasculature, myelinated axons, and neuronal cells in the first layers of the somatosensory cortex of mice in vivo.
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Affiliation(s)
- Paul J Marchand
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire d' Optique Biomédicale, Lausanne, Switzerland
| | - Daniel Szlag
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire d' Optique Biomédicale, Lausanne, Switzerland
| | - Arno Bouwens
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire d' Optique Biomédicale, Lausanne, Switzerland
| | - Theo Lasser
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire d' Optique Biomédicale, Lausanne, Switzerland
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19
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Rasmussen PM, Smith AF, Sakadžić S, Boas DA, Pries AR, Secomb TW, Østergaard L. Model-based inference from microvascular measurements: Combining experimental measurements and model predictions using a Bayesian probabilistic approach. Microcirculation 2018; 24. [PMID: 27987383 DOI: 10.1111/micc.12343] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 12/12/2016] [Indexed: 01/23/2023]
Abstract
OBJECTIVE In vivo imaging of the microcirculation and network-oriented modeling have emerged as powerful means of studying microvascular function and understanding its physiological significance. Network-oriented modeling may provide the means of summarizing vast amounts of data produced by high-throughput imaging techniques in terms of key, physiological indices. To estimate such indices with sufficient certainty, however, network-oriented analysis must be robust to the inevitable presence of uncertainty due to measurement errors as well as model errors. METHODS We propose the Bayesian probabilistic data analysis framework as a means of integrating experimental measurements and network model simulations into a combined and statistically coherent analysis. The framework naturally handles noisy measurements and provides posterior distributions of model parameters as well as physiological indices associated with uncertainty. RESULTS We applied the analysis framework to experimental data from three rat mesentery networks and one mouse brain cortex network. We inferred distributions for more than 500 unknown pressure and hematocrit boundary conditions. Model predictions were consistent with previous analyses, and remained robust when measurements were omitted from model calibration. CONCLUSION Our Bayesian probabilistic approach may be suitable for optimizing data acquisition and for analyzing and reporting large data sets acquired as part of microvascular imaging studies.
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Affiliation(s)
- Peter M Rasmussen
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience and MINDLab, Aarhus University Hospital, Aarhus, Denmark
| | - Amy F Smith
- Institut de Mécanique des Fluides de Toulouse (IMFT) - Université de Toulouse, CNRS-INPT-UPS, Toulouse, France
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - David A Boas
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.,Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
| | - Axel R Pries
- Department of Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Timothy W Secomb
- Department of Physiology, University of Arizona, Tucson, AZ, USA
| | - Leif Østergaard
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience and MINDLab, Aarhus University Hospital, Aarhus, Denmark.,Department of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark
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20
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Ginner L, Schmoll T, Kumar A, Salas M, Pricoupenko N, Wurster LM, Leitgeb RA. Holographic line field en-face OCT with digital adaptive optics in the retina in vivo. BIOMEDICAL OPTICS EXPRESS 2018; 9:472-485. [PMID: 29552387 PMCID: PMC5854052 DOI: 10.1364/boe.9.000472] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/22/2017] [Accepted: 12/22/2017] [Indexed: 05/05/2023]
Abstract
We demonstrate a high-resolution line field en-face time domain optical coherence tomography (OCT) system using an off-axis holography configuration. Line field en-face OCT produces high speed en-face images at rates of up to 100 Hz. The high frame rate favors good phase stability across the lateral field-of-view which is indispensable for digital adaptive optics (DAO). Human retinal structures are acquired in-vivo with a broadband light source at 840 nm, and line rates of 10 kHz to 100 kHz. Structures of different retinal layers, such as photoreceptors, capillaries, and nerve fibers are visualized with high resolution of 2.8 µm and 5.5 µm in lateral directions. Subaperture based DAO is successfully applied to increase the visibility of cone-photoreceptors and nerve fibers. Furthermore, en-face Doppler OCT maps are generated based on calculating the differential phase shifts between recorded lines.
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Affiliation(s)
- Laurin Ginner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and its Translation to Medicine, Medical University of Vienna, Austria
| | | | - Abhishek Kumar
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Matthias Salas
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and its Translation to Medicine, Medical University of Vienna, Austria
| | - Nastassia Pricoupenko
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Lara M. Wurster
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Rainer A. Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and its Translation to Medicine, Medical University of Vienna, Austria
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21
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Gagnon L, Sakadžić S, Lesage F, Pouliot P, Dale AM, Devor A, Buxton RB, Boas DA. Validation and optimization of hypercapnic-calibrated fMRI from oxygen-sensitive two-photon microscopy. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0359. [PMID: 27574311 DOI: 10.1098/rstb.2015.0359] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/13/2016] [Indexed: 01/30/2023] Open
Abstract
Hypercapnic-calibrated fMRI allows the estimation of the relative changes in the cerebral metabolic rate of oxygen (rCMRO2) from combined BOLD and arterial spin labelling measurements during a functional task, and promises to permit more quantitative analyses of brain activity patterns. The estimation relies on a macroscopic model of the BOLD effect that balances oxygen delivery and consumption to predict haemoglobin oxygenation and the BOLD signal. The accuracy of calibrated fMRI approaches has not been firmly established, which is limiting their broader adoption. We use our recently developed microscopic vascular anatomical network model in mice as a ground truth simulator to test the accuracy of macroscopic, lumped-parameter BOLD models. In particular, we investigate the original Davis model and a more recent heuristic simplification. We find that these macroscopic models are inaccurate using the originally defined parameters, but that the accuracy can be significantly improved by redefining the model parameters to take on new values. In particular, we find that the parameter α that relates cerebral blood-volume changes to cerebral blood-flow changes is significantly smaller than typically assumed and that the optimal value changes with magnetic field strength. The results are encouraging in that they support the use of simple BOLD models to quantify BOLD signals, but further work is needed to understand the physiological interpretation of the redefined model parameters.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'.
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Affiliation(s)
- Louis Gagnon
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA Department of Medicine, Laval University, Quebec City, Quebec, Canada Deparment of Electrical Engineering, École Polytechnique Montreal, Montreal, Quebec, Canada
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Frédéric Lesage
- Deparment of Electrical Engineering, École Polytechnique Montreal, Montreal, Quebec, Canada
| | - Philippe Pouliot
- Deparment of Electrical Engineering, École Polytechnique Montreal, Montreal, Quebec, Canada
| | - Anders M Dale
- Department of Neurosciences and Radiology, UCSD, La Jolla, CA, USA
| | - Anna Devor
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA Department of Neurosciences and Radiology, UCSD, La Jolla, CA, USA
| | | | - David A Boas
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
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22
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Zhu J, Merkle CW, Bernucci MT, Chong SP, Srinivasan VJ. Can OCT Angiography Be Made a Quantitative Blood Measurement Tool? APPLIED SCIENCES-BASEL 2017; 7. [PMID: 30009045 PMCID: PMC6042878 DOI: 10.3390/app7070687] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Optical Coherence Tomography Angiography (OCTA) refers to a powerful class of OCT scanning protocols and algorithms that selectively enhance the imaging of blood vessel lumens, based mainly on the motion and scattering of red blood cells (RBCs). Though OCTA is widely used in clinical and basic science applications for visualization of perfused blood vessels, OCTA is still primarily a qualitative tool. However, more quantitative hemodynamic information would better delineate disease mechanisms, and potentially improve the sensitivity for detecting early stages of disease. Here, we take a broader view of OCTA in the context of microvascular hemodynamics and light scattering. Paying particular attention to the unique challenges presented by capillaries versus larger supplying and draining vessels, we critically assess opportunities and challenges in making OCTA a quantitative tool.
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Affiliation(s)
- Jun Zhu
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA
| | - Conrad W. Merkle
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA
| | - Marcel T. Bernucci
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA
| | - Shau Poh Chong
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA
| | - Vivek J. Srinivasan
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA
- Department of Ophthalmology and Vision Science, School of Medicine, University of California Davis, Sacramento, CA 95817, USA
- Correspondence: ; Tel.: +1-530-752-9277
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23
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Chen CL, Wang RK. Optical coherence tomography based angiography [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:1056-1082. [PMID: 28271003 PMCID: PMC5330554 DOI: 10.1364/boe.8.001056] [Citation(s) in RCA: 270] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/16/2017] [Indexed: 05/18/2023]
Abstract
Optical coherence tomography (OCT)-based angiography (OCTA) provides in vivo, three-dimensional vascular information by the use of flowing red blood cells as intrinsic contrast agents, enabling the visualization of functional vessel networks within microcirculatory tissue beds non-invasively, without a need of dye injection. Because of these attributes, OCTA has been rapidly translated to clinical ophthalmology within a short period of time in the development. Various OCTA algorithms have been developed to detect the functional micro-vasculatures in vivo by utilizing different components of OCT signals, including phase-signal-based OCTA, intensity-signal-based OCTA and complex-signal-based OCTA. All these algorithms have shown, in one way or another, their clinical values in revealing micro-vasculatures in biological tissues in vivo, identifying abnormal vascular networks or vessel impairment zones in retinal and skin pathologies, detecting vessel patterns and angiogenesis in eyes with age-related macular degeneration and in skin and brain with tumors, and monitoring responses to hypoxia in the brain tissue. The purpose of this paper is to provide a technical oriented overview of the OCTA developments and their potential pre-clinical and clinical applications, and to shed some lights on its future perspectives. Because of its clinical translation to ophthalmology, this review intentionally places a slightly more weight on ophthalmic OCT angiography.
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Affiliation(s)
- Chieh-Li Chen
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
- Department of Ophthalmology, University of Washington, 325 9th Ave, Seattle, WA 98104, USA
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
- Department of Ophthalmology, University of Washington, 325 9th Ave, Seattle, WA 98104, USA
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24
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You J, Li A, Du C, Pan Y. Volumetric Doppler angle correction for ultrahigh-resolution optical coherence Doppler tomography. APPLIED PHYSICS LETTERS 2017; 110:011102. [PMID: 28104922 PMCID: PMC5218966 DOI: 10.1063/1.4973367] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 11/12/2016] [Indexed: 05/14/2023]
Abstract
Ultrahigh-resolution optical coherence Doppler tomography (μODT) demonstrates great potential for quantitative blood flow imaging owing to its large field of view and capillary resolution. However, μODT only detects the axial flow velocity and requires Doppler angle correction to retrieve the absolute velocity. Although methods for Doppler angle tracking of single or few large vessels have been reported, a method that enables angle correction of the entire 3D microvascular networks remains a challenge. Here, we present a method based on eigenvalue analysis of 3D Hessian matrix to retrieve the orientation of each tubular vessel. As the algorithm is voxel based, it is suitable for effective tracking of Doppler angle matrix and restoring the absolute flow over the 3D vascular flow networks. We present results on simulation and flow phantom studies to show its efficacy for accurate 3D angle tracking and absolute flow correction. Then, we perform an in vivo validation study on mouse micro-circulatory cerebral blood flow (CBF) networks, which clearly demonstrates the capability of this method for tracking the Doppler angle matrix of the highly complex 3D CBF networks.
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Affiliation(s)
- Jiang You
- Department of Biomedical Engineering, Stony Brook University , Stony Brook, New York 11794, USA
| | - Ang Li
- Department of Biomedical Engineering, Stony Brook University , Stony Brook, New York 11794, USA
| | - Congwu Du
- Department of Biomedical Engineering, Stony Brook University , Stony Brook, New York 11794, USA
| | - Yingtian Pan
- Department of Biomedical Engineering, Stony Brook University , Stony Brook, New York 11794, USA
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25
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Marchand PJ, Bouwens A, Bolmont T, Shamaei VK, Nguyen D, Szlag D, Extermann J, Lasser T. Statistical parametric mapping of stimuli evoked changes in total blood flow velocity in the mouse cortex obtained with extended-focus optical coherence microscopy. BIOMEDICAL OPTICS EXPRESS 2017; 8:1-15. [PMID: 28101397 PMCID: PMC5231283 DOI: 10.1364/boe.8.000001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/11/2016] [Accepted: 11/26/2016] [Indexed: 05/08/2023]
Abstract
Functional magnetic resonance (fMRI) imaging is the current gold-standard in neuroimaging. fMRI exploits local changes in blood oxygenation to map neuronal activity over the entire brain. However, its spatial resolution is currently limited to a few hundreds of microns. Here we use extended-focus optical coherence microscopy (xfOCM) to quantitatively measure changes in blood flow velocity during functional hyperaemia at high spatio-temporal resolution in the somatosensory cortex of mice. As optical coherence microscopy acquires hundreds of depth slices simultaneously, blood flow velocity measurements can be performed over several vessels in parallel. We present the proof-of-principle of an optimised statistical parametric mapping framework to analyse quantitative blood flow timetraces acquired with xfOCM using the general linear model. We demonstrate the feasibility of generating maps of cortical hemodynamic reactivity at the capillary level with optical coherence microscopy. To validate our method, we exploited 3 stimulation paradigms, covering different temporal dynamics and stimulated limbs, and demonstrated its repeatability over 2 trials, separated by a week.
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26
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Lee J, Gursoy-Ozdemir Y, Fu B, Boas DA, Dalkara T. Optical coherence tomography imaging of capillary reperfusion after ischemic stroke. APPLIED OPTICS 2016; 55:9526-9531. [PMID: 27869849 PMCID: PMC6420785 DOI: 10.1364/ao.55.009526] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Although progress has been made for recanalization therapies after ischemic stroke, post-treatment imaging studies show that tissue reperfusion cannot be attained despite satisfactory recanalization in a significant percentage of patients. Hence, investigation of microcirculatory changes in both surface and deep cortical levels after ischemia reperfusion is important for understanding the post-stroke blood flow dynamics. In this study, we applied optical coherence tomography (OCT) imaging of cerebral blood flow for the quantification of the microcirculatory changes. We obtained OCT microangiogram of the brain cortex in a mouse stroke model and analyzed the data to trace changes in the capillary perfusion level (CPL) before, during, and after the stroke. The CPL changes were estimated in 1 and 2 h ischemia groups as well as in a non-ischemic sham-operated group. For the estimation of CPL, a decorrelation amplitude-based algorithm was implemented and used. As a result, the CPL considerably decreased during ischemia but recovered to the baseline when recanalization was performed 1 h after ischemia; however, the CPL was significantly reduced when recanalization was delayed to 2 h after ischemia. These data demonstrate that ischemia causes microcirculation dysfunction, leading to a decreased capillary reperfusion after recanalization. Microcirculatory no-reflow warrants more rigorous assessment in clinical trials, whereas advanced optical imaging techniques may provide mechanistic insight and solutions in experimental studies.
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Affiliation(s)
- Jonghwan Lee
- School of Engineering, Institute for Brain Science, Brown University, Providence, Rhode Island 02912, USA
- Corresponding author:
| | - Yasemin Gursoy-Ozdemir
- Currently at Koc University School of Medicine, Department of Neurology, Istanbul, Turkey
- Institute of Neurological Sciences and Psychiatry and Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Buyin Fu
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA
| | - David A. Boas
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry and Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
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27
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Wylęgała A, Teper S, Dobrowolski D, Wylęgała E. Optical coherence angiography: A review. Medicine (Baltimore) 2016; 95:e4907. [PMID: 27741104 PMCID: PMC5072931 DOI: 10.1097/md.0000000000004907] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 08/16/2016] [Accepted: 08/26/2016] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Retinal vascular diseases are one of the most common causes of blindness in the developed world. Optical Coherence Tomography Angiography (OCT-A) is a new noninvasive method that uses several algorithms to detect blood movement. This enables the creation of high-resolution vascular images with contrast depicting motionless tissue. METHODS This review presents the results of articles relevant to age-related macular degeneration (AMD), diabetic retinopathy (DR), and OCT-A. The OCT-A technique can successfully be used in the diagnosis of neovascularization, retinal vein occlusion (RVO) and retinal artery occlusion (RAO), vessel abnormalities and even anterior segment neovascularization. OCT-A can also be applied to compute data such as vessel density, and flow index in both superficial and deep plexuses. RESULTS Many studies have compared fluorescein angiography with OCT-A. Other studies have reported differences in vascular density in AMD patients and have compared them with people having healthy eyes. Although OCT-A offers rapid picture acquisition, high repeatability and resolution, it also has many drawbacks. The most common are: motion artifacts, projections from overlying vessels and limited field of view.An interesting new application is the possibility to assess changes during antivascular endothelial growth factor (anti-VEGF) therapy. Another function of OCT-A is the possible application in the study of choriocapillaries in many fields of ocular pathology. CONCLUSION OCT-A is a new promising method that allows the visualization of the retinal vascular network and the counting of blood flow parameters. This technique provides reliable images useful in clinical routines.
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Affiliation(s)
- Adam Wylęgała
- Departament of Ophthalmology, Santa Barbara Hospital, Sosnowiec
| | - Sławomir Teper
- Ophthalmology Clinic, Railway Hospital Katowice, II School of Medicine with the Division of Dentistry in Zabrze, Silesian Medical University, Katowice, Poland
| | - Dariusz Dobrowolski
- Departament of Ophthalmology, Santa Barbara Hospital, Sosnowiec
- Ophthalmology Clinic, Railway Hospital Katowice, II School of Medicine with the Division of Dentistry in Zabrze, Silesian Medical University, Katowice, Poland
| | - Edward Wylęgała
- Ophthalmology Clinic, Railway Hospital Katowice, II School of Medicine with the Division of Dentistry in Zabrze, Silesian Medical University, Katowice, Poland
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Gagnon L, Smith AF, Boas DA, Devor A, Secomb TW, Sakadžić S. Modeling of Cerebral Oxygen Transport Based on In vivo Microscopic Imaging of Microvascular Network Structure, Blood Flow, and Oxygenation. Front Comput Neurosci 2016; 10:82. [PMID: 27630556 PMCID: PMC5006088 DOI: 10.3389/fncom.2016.00082] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 07/25/2016] [Indexed: 01/09/2023] Open
Abstract
Oxygen is delivered to brain tissue by a dense network of microvessels, which actively control cerebral blood flow (CBF) through vasodilation and contraction in response to changing levels of neural activity. Understanding these network-level processes is immediately relevant for (1) interpretation of functional Magnetic Resonance Imaging (fMRI) signals, and (2) investigation of neurological diseases in which a deterioration of neurovascular and neuro-metabolic physiology contributes to motor and cognitive decline. Experimental data on the structure, flow and oxygen levels of microvascular networks are needed, together with theoretical methods to integrate this information and predict physiologically relevant properties that are not directly measurable. Recent progress in optical imaging technologies for high-resolution in vivo measurement of the cerebral microvascular architecture, blood flow, and oxygenation enables construction of detailed computational models of cerebral hemodynamics and oxygen transport based on realistic three-dimensional microvascular networks. In this article, we review state-of-the-art optical microscopy technologies for quantitative in vivo imaging of cerebral microvascular structure, blood flow and oxygenation, and theoretical methods that utilize such data to generate spatially resolved models for blood flow and oxygen transport. These “bottom-up” models are essential for the understanding of the processes governing brain oxygenation in normal and disease states and for eventual translation of the lessons learned from animal studies to humans.
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Affiliation(s)
- Louis Gagnon
- Optics Division, Department of Radiology, MHG/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School Charlestown, MA, USA
| | - Amy F Smith
- Institut de Mécanique des Fluides de ToulouseToulouse, France; Department of Physiology, University of ArizonaTucson, AZ, USA
| | - David A Boas
- Optics Division, Department of Radiology, MHG/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School Charlestown, MA, USA
| | - Anna Devor
- Optics Division, Department of Radiology, MHG/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical SchoolCharlestown, MA, USA; Departments of Neurosciences and Radiology, University of California, San DiegoLa Jolla, CA, USA
| | | | - Sava Sakadžić
- Optics Division, Department of Radiology, MHG/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School Charlestown, MA, USA
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29
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CLEMMER JOHN, PRABHU RAJ, CHEN JOSEPH, COLEBECK ERIN, PRIDDY LAURENB, MCCOLLUM MICHAEL, BRAZILE BRYN, WHITTINGTON WILBUR, WARDLAW JENNIFERL, RHEE HONGJOO, HORSTEMEYER MF, WILLIAMS LAKIESHAN, LIAO JUN. EXPERIMENTAL OBSERVATION OF HIGH STRAIN RATE RESPONSES OF PORCINE BRAIN, LIVER, AND TENDON. J MECH MED BIOL 2016. [DOI: 10.1142/s0219519416500329] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
High strain rate compression of soft tissues has recently gained attention due to its application in computational simulation of traumatic injuries. To understand high rate tissue behavior, a comparative study is needed to examine the biomechanical responses of multiple soft tissues. We hypothesized that the underlying mechanisms of soft tissue high rate compression is dependent upon water, microstructural organization, and extracellular matrix (ECM). Porcine brain, liver, and tendon, which have similar material density (brain: 1.05[Formula: see text]g/cm3, liver: 1.06[Formula: see text]g/cm3, and tendon: 1.12[Formula: see text]g/cm3) and water content (brain: [Formula: see text][Formula: see text]78%, liver: [Formula: see text][Formula: see text]71–75%, and tendon: [Formula: see text][Formula: see text]70%) but different cellularity and ECM properties, were subjected to polymeric split Hopkinson pressure bar (PSHPB) testing. Hydrated brain tissue, due to its high microstructural cavities (cavity area [Formula: see text]) and low ECM content, had a high initial stress spike of [Formula: see text][Formula: see text]MPa. Hydrated liver, with moderate microstructural cavities (cavity area [Formula: see text]) and moderate ECM content, had a moderate stress spike of [Formula: see text][Formula: see text]MPa. Hydrated tendon had low microstructural cavities (cavity area [Formula: see text]) and high ECM content and had a minimal initial stress spike of [Formula: see text][Formula: see text]MPa. Electron microscopy of the tissues’ microstructural cavities revealed a first-order estimation of water content that was not bound to ECM (e.g., intracellular water). Linear regression analysis showed that the initial spike was highly correlated ([Formula: see text]) with intracellular water. To understand the role of water in each tissue’s response to high deformation, each soft tissue was completely dehydrated and subjected to the same PSHPB compression test. After removal of all the water, neither the brain, liver, nor tendon revealed an initial stress spike, implicating the essential nature of water in the initial responses of high-rate compression. These results suggest that cellular water and ECM content play a critical role in the biomechanical responses to high strain rate compression.
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Affiliation(s)
- JOHN CLEMMER
- Tissue Bioengineering Laboratory and Injury Mechanics Laboratory, Department of Biological Engineering, Mississippi State University, Mississippi State, MS 39762, USA
| | - RAJ PRABHU
- Tissue Bioengineering Laboratory and Injury Mechanics Laboratory, Department of Biological Engineering, Mississippi State University, Mississippi State, MS 39762, USA
- Computational Manufacture and Design, Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, MS 39762, USA
| | - JOSEPH CHEN
- Tissue Bioengineering Laboratory and Injury Mechanics Laboratory, Department of Biological Engineering, Mississippi State University, Mississippi State, MS 39762, USA
| | - ERIN COLEBECK
- Tissue Bioengineering Laboratory and Injury Mechanics Laboratory, Department of Biological Engineering, Mississippi State University, Mississippi State, MS 39762, USA
| | - LAUREN B. PRIDDY
- Tissue Bioengineering Laboratory and Injury Mechanics Laboratory, Department of Biological Engineering, Mississippi State University, Mississippi State, MS 39762, USA
- Computational Manufacture and Design, Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, MS 39762, USA
| | - MICHAEL MCCOLLUM
- Computational Manufacture and Design, Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, MS 39762, USA
| | - BRYN BRAZILE
- Tissue Bioengineering Laboratory and Injury Mechanics Laboratory, Department of Biological Engineering, Mississippi State University, Mississippi State, MS 39762, USA
- Computational Manufacture and Design, Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, MS 39762, USA
| | - WILBUR WHITTINGTON
- Computational Manufacture and Design, Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, MS 39762, USA
| | - JENNIFER L. WARDLAW
- College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, USA
| | - HONGJOO RHEE
- Computational Manufacture and Design, Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, MS 39762, USA
| | - M. F. HORSTEMEYER
- Computational Manufacture and Design, Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, MS 39762, USA
| | - LAKIESHA N. WILLIAMS
- Tissue Bioengineering Laboratory and Injury Mechanics Laboratory, Department of Biological Engineering, Mississippi State University, Mississippi State, MS 39762, USA
- Computational Manufacture and Design, Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, MS 39762, USA
| | - JUN LIAO
- Tissue Bioengineering Laboratory and Injury Mechanics Laboratory, Department of Biological Engineering, Mississippi State University, Mississippi State, MS 39762, USA
- Computational Manufacture and Design, Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, MS 39762, USA
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30
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Makita S, Kurokawa K, Hong YJ, Miura M, Yasuno Y. Noise-immune complex correlation for optical coherence angiography based on standard and Jones matrix optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2016; 7:1525-48. [PMID: 27446673 PMCID: PMC4929659 DOI: 10.1364/boe.7.001525] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 03/24/2016] [Accepted: 03/24/2016] [Indexed: 05/18/2023]
Abstract
This paper describes a complex correlation mapping algorithm for optical coherence angiography (cmOCA). The proposed algorithm avoids the signal-to-noise ratio dependence and exhibits low noise in vasculature imaging. The complex correlation coefficient of the signals, rather than that of the measured data are estimated, and two-step averaging is introduced. Algorithms of motion artifact removal based on non perfusing tissue detection using correlation are developed. The algorithms are implemented with Jones-matrix OCT. Simultaneous imaging of pigmented tissue and vasculature is also achieved using degree of polarization uniformity imaging with cmOCA. An application of cmOCA to in vivo posterior human eyes is presented to demonstrate that high-contrast images of patients' eyes can be obtained.
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Affiliation(s)
- Shuichi Makita
- Computational Optics Group, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573,
Japan
| | - Kazuhiro Kurokawa
- Computational Optics Group, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573,
Japan
| | - Young-Joo Hong
- Computational Optics Group, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573,
Japan
| | - Masahiro Miura
- Department of Ophthalmology, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Chuo, Ami, Inashiki, Ibaraki 300-0395,
Japan
| | - Yoshiaki Yasuno
- Computational Optics Group, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573,
Japan
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31
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Qi L, Zhu J, Hancock AM, Dai C, Zhang X, Frostig RD, Chen Z. Fully distributed absolute blood flow velocity measurement for middle cerebral arteries using Doppler optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2016; 7:601-15. [PMID: 26977365 PMCID: PMC4771474 DOI: 10.1364/boe.7.000601] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 01/08/2016] [Accepted: 01/08/2016] [Indexed: 05/03/2023]
Abstract
Doppler optical coherence tomography (DOCT) is considered one of the most promising functional imaging modalities for neuro biology research and has demonstrated the ability to quantify cerebral blood flow velocity at a high accuracy. However, the measurement of total absolute blood flow velocity (BFV) of major cerebral arteries is still a difficult problem since it is related to vessel geometry. In this paper, we present a volumetric vessel reconstruction approach that is capable of measuring the absolute BFV distributed along the entire middle cerebral artery (MCA) within a large field-of-view. The Doppler angle at each point of the MCA, representing the vessel geometry, is derived analytically by localizing the artery from pure DOCT images through vessel segmentation and skeletonization. Our approach could achieve automatic quantification of the fully distributed absolute BFV across different vessel branches. Experiments on rodents using swept-source optical coherence tomography showed that our approach was able to reveal the consequences of permanent MCA occlusion with absolute BFV measurement.
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Affiliation(s)
- Li Qi
- Institute of Optical Communication Engineering and College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu, 210093, China
- Beckman Laser Institute, University of California, Irvine, Irvine, California 92612, USA
| | - Jiang Zhu
- Beckman Laser Institute, University of California, Irvine, Irvine, California 92612, USA
- Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92697, USA
| | - Aneeka M. Hancock
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, California, USA
- The Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, California, USA
| | - Cuixia Dai
- Beckman Laser Institute, University of California, Irvine, Irvine, California 92612, USA
| | - Xuping Zhang
- Institute of Optical Communication Engineering and College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Ron D. Frostig
- Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92697, USA
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, California, USA
- The Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, California, USA
| | - Zhongping Chen
- Beckman Laser Institute, University of California, Irvine, Irvine, California 92612, USA
- Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92697, USA
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32
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Baran U, Wang RK. Review of optical coherence tomography based angiography in neuroscience. NEUROPHOTONICS 2016; 3:010902. [PMID: 26835484 PMCID: PMC4719095 DOI: 10.1117/1.nph.3.1.010902] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/14/2015] [Indexed: 05/09/2023]
Abstract
The brain is a complex ecosystem, consisting of multiple layers and tissue compartments. To facilitate the understanding of its function and its response to neurological insults, a fast in vivo imaging tool with a micron-level resolution, which can provide a field of view at a few millimeters, is desirable. Optical coherence tomography (OCT) is a noninvasive method for imaging three-dimensional biological tissues with high resolution ([Formula: see text]) and without a need for contrast agents. Recent development of OCT-based angiography has started to shed some new light on cerebral hemodynamics in neuroscience. We give an overview of the recent developments of OCT-based imaging techniques for neuroscience applications in rodents. We summarize today's technological alternatives for OCT-based angiography for neuroscience and provide a discussion of challenges and opportunities. Moreover, a summary of OCT angiography studies for stroke, traumatic brain injury, and subarachnoid hemorrhage cases on rodents is provided.
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Affiliation(s)
- Utku Baran
- University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195, United States
- University of Washington, Department of Electrical Engineering, 185 Stevens Way, Seattle, Washington 98195, United States
| | - Ruikang K. Wang
- University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195, United States
- Address all correspondence to: Ruikang K. Wang, E-mail:
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Ellis JA, Banu M, Hossain SS, Singh-Moon R, Lavine SD, Bruce JN, Joshi S. Reassessing the Role of Intra-Arterial Drug Delivery for Glioblastoma Multiforme Treatment. JOURNAL OF DRUG DELIVERY 2015; 2015:405735. [PMID: 26819758 PMCID: PMC4706947 DOI: 10.1155/2015/405735] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 11/16/2015] [Indexed: 12/16/2022]
Abstract
Effective treatment for glioblastoma (GBM) will likely require targeted delivery of several specific pharmacological agents simultaneously. Intra-arterial (IA) delivery is one technique for targeting the tumor site with multiple agents. Although IA chemotherapy for glioblastoma (GBM) has been attempted since the 1950s, the predicted benefits remain unproven in clinical practice. This review focuses on innovative approaches to IA drug delivery in treating GBM. Guided by novel in vitro and in vivo optical measurements, newer pharmacokinetic models promise to better define the complex relationship between background cerebral blood flow and drug injection parameters. Advanced optical technologies and tracers, unique nanoparticles designs, new cellular targets, and rational drug formulations are continuously modifying the therapeutic landscape for GBM. Personalized treatment approaches are emerging; however, such tailored approaches will largely depend on effective drug delivery techniques and on the ability to simultaneously deliver multidrug regimens. These new paradigms for tumor-selective drug delivery herald dramatic improvements in the effectiveness of IA chemotherapy for GBM. Therefore, within this context of so-called "precision medicine," the role of IA delivery for GBM is thoroughly reassessed.
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Affiliation(s)
- Jason A. Ellis
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY 10032, USA
| | - Matei Banu
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY 10032, USA
| | - Shaolie S. Hossain
- Department of Molecular Cardiology, Texas Heart Institute, Houston, TX 77030, USA
| | - Rajinder Singh-Moon
- School of Engineering and Applied Science, Columbia University, New York, NY 10032, USA
| | - Sean D. Lavine
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY 10032, USA
| | - Jeffrey N. Bruce
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY 10032, USA
| | - Shailendra Joshi
- Department of Anesthesiology, Columbia University Medical Center, New York, NY 10032, USA
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34
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Sakadžić S, Lee J, Boas DA, Ayata C. High-resolution in vivo optical imaging of stroke injury and repair. Brain Res 2015; 1623:174-92. [PMID: 25960347 PMCID: PMC4569527 DOI: 10.1016/j.brainres.2015.04.044] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 12/15/2022]
Abstract
Central nervous system (CNS) function and dysfunction are best understood within a framework of interactions between neuronal, glial and vascular compartments comprising the neurovascular unit (NVU), all of which contribute to stroke-induced CNS injury, plasticity, repair, and recovery. Recent advances in in vivo optical microscopy have enabled us to observe and interrogate cells and their processes with high spatial resolution in real time and in their natural environment deep in the brain tissue. Here, we review some of these state-of-the-art imaging techniques with an emphasis on imaging the interactions among the constituents of the NVU during ischemic injury and repair in small animal models. This article is part of a Special Issue entitled SI: Cell Interactions In Stroke.
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Affiliation(s)
- Sava Sakadžić
- Optics Division, MHG/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
| | - Jonghwan Lee
- Optics Division, MHG/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - David A Boas
- Optics Division, MHG/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA; Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
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35
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Scott GG, Coats B. Microstructural Characterization of the Pia-Arachnoid Complex Using Optical Coherence Tomography. IEEE TRANSACTIONS ON MEDICAL IMAGING 2015; 34:1452-1459. [PMID: 25643401 DOI: 10.1109/tmi.2015.2396527] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Traumatic brain injury (TBI) is one of the leading causes of death and disability in the world, and is often identified by the presence of subdural and/or subarachnoid hemorrhages that develop from ruptured cortical vessels during brain-skull displacement. The pia-arachnoid complex (PAC), also known as the leptomeninges, is the major mechanical connection between the brain and skull, and influences cortical vessel deformation and rupture following brain trauma. This complex consists of cerebrospinal fluid, arachnoid trabeculae, and subarachnoid vasculature sandwiched between the arachnoid and pia mater membranes. Remarkably, studies of the tissues in the PAC are largely qualitative and do not provide numerical metrics of population density and variability of the arachnoid trabeculae and subarachnoid vasculature. In this study, microstructural imaging was performed on the PAC to numerically quantify these metrics. Five porcine brains were perfusion-fixed and imaged in situ using optical coherence tomography with micrometer resolution. Image processing was performed to estimate the volume fraction (VF) of the arachnoid trabeculae and subarachnoid vasculature in 12 regions of the brain. High regional variability was found within each brain, with individual brains exhibiting up to a 38.4 percentage-point range in VF. Regions with high VF were often next to regions with low VF. This suggests that some areas of the brain may be mechanically weaker, increasing their susceptibility to hemorrhage during TBI events. This study provides the first quantifiable data of arachnoid trabeculae and subarachnoid vasculature distribution within the PAC and will be valuable to understanding brain biomechanics during head trauma.
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Kazmi SMS, Richards LM, Schrandt CJ, Davis MA, Dunn AK. Expanding applications, accuracy, and interpretation of laser speckle contrast imaging of cerebral blood flow. J Cereb Blood Flow Metab 2015; 35:1076-84. [PMID: 25944593 PMCID: PMC4640282 DOI: 10.1038/jcbfm.2015.84] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 02/17/2015] [Accepted: 03/09/2015] [Indexed: 12/21/2022]
Abstract
Laser speckle contrast imaging (LSCI) provides a rapid characterization of cortical flow dynamics for functional monitoring of the microcirculation. The technique stems from interactions of laser light with moving particles. These interactions encode the encountered Doppler phenomena within a random interference pattern imaged in widefield, known as laser speckle. Studies of neurovascular function and coupling with LSCI have benefited from the real-time characterization of functional dynamics in the laboratory setting through quantification of perfusion dynamics. While the technique has largely been relegated to acute small animal imaging, its scalability is being assessed and characterized for both chronic and clinical neurovascular imaging.
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Affiliation(s)
- S M Shams Kazmi
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas, USA
| | - Lisa M Richards
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas, USA
| | - Christian J Schrandt
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas, USA
| | - Mitchell A Davis
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas, USA
| | - Andrew K Dunn
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas, USA
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37
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Impaired leptomeningeal collateral flow contributes to the poor outcome following experimental stroke in the Type 2 diabetic mice. J Neurosci 2015; 35:3851-64. [PMID: 25740515 DOI: 10.1523/jneurosci.3838-14.2015] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Collateral status is an independent predictor of stroke outcome. However, the spatiotemporal manner in which collateral flow maintains cerebral perfusion during cerebral ischemia is poorly understood. Diabetes exacerbates ischemic brain damage, although the impact of diabetes on collateral dynamics remains to be established. Using Doppler optical coherent tomography, a robust recruitment of leptomeningeal collateral flow was detected immediately after middle cerebral artery (MCA) occlusion in C57BL/6 mice, and it continued to grow over the course of 1 week. In contrast, an impairment of collateral recruitment was evident in the Type 2 diabetic db/db mice, which coincided with a worse stroke outcome compared with their normoglycemic counterpart db/+, despite their equally well-collateralized leptomeningeal anastomoses. Similar to the wild-type mice, both db/+ and db/db mice underwent collateral growth 7 d after MCA stroke, although db/db mice still exhibited significantly reduced retrograde flow into the MCA territory chronically. Acutely induced hyperglycemia in the db/+ mice did not impair collateral flow after stroke, suggesting that the state of hyperglycemia alone was not sufficient to impact collateral flow. Human albumin was efficacious in improving collateral flow and outcome after stroke in the db/db mice, enabling perfusion to proximal MCA territory that was usually not reached by retrograde flow from anterior cerebral artery without treatment. Our results suggest that the impaired collateral status contributes to the exacerbated ischemic injury in mice with Type 2 diabetes, and modulation of collateral flow has beneficial effects on stroke outcome among these subjects.
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38
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Park K, You J, Du C, Pan Y. Cranial window implantation on mouse cortex to study microvascular change induced by cocaine. Quant Imaging Med Surg 2015; 5:97-107. [PMID: 25694959 DOI: 10.3978/j.issn.2223-4292.2014.11.31] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 10/31/2014] [Indexed: 11/14/2022]
Abstract
Cocaine-induced stroke is among the most serious medical complications associated with cocaine's abuse. However, the extent to which chronic cocaine may induce silent microischemia predisposing the cerebral tissue to neurotoxicity has not been investigated; in part, because of limitations of current neuroimaging tools, that is, lack of high spatiotemporal resolution and sensitivity to simultaneously measure cerebral blood flow (CBF) in vessels of different calibers quantitatively and over a large field of view (FOV). Optical coherence tomography (OCT) technique allows us to image three dimensional (3D) cerebrovascular network (including artery, vein, and capillary), and provides high resolution angiography of the cerebral vasculature and quantitative CBF velocity (CBFv) within the individual vessels in the network. In order to monitor the neurovascular changes from an in vivo brain along with the chronic cocaine exposure, we have developed an approach of implanting a cranial window on mouse brain to achieve long-term cortical imaging. The cranial window was implanted on sensorimotor cortex area in two animal groups, i.e., control group [saline treatment, ~0.1 cc/10 g/day, intraperitoneal injection (i.p.)] and chronic cocaine group (cocaine treatment, 30 mg/kg/day i.p.). After implantation, the cortex of individual animal was periodically imaged by OCT and stereoscope to provide angiography and quantitative CBFv of the cerebral vascular network, as well as the surface imaging of the brain. We have observed vascular hemodynamic changes (i.e., CBFv changes) induced by the cranial preparation in both animal groups, including the inflammatory response of brain shortly after the surgery (i.e., <5 days) followed by wound-healing process (i.e., >5 days) in the brain. Importantly, by comparing with the control animals, the surgical-related vascular physiology changes in the cortex can be calibrated, so that the cocaine-induced hemodynamic changes in the neurovasculature can be determined in the cocaine animals. Our results demonstrate that this methodology can be used to explore the neurovascular functional changes induced by the brain diseases such as drug addiction.
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Affiliation(s)
- Kicheon Park
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Jiang You
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Congwu Du
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Yingtian Pan
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
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39
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Gagnon L, Sakadžić S, Lesage F, Mandeville ET, Fang Q, Yaseen MA, Boas DA. Multimodal reconstruction of microvascular-flow distributions using combined two-photon microscopy and Doppler optical coherence tomography. NEUROPHOTONICS 2015; 2:015008. [PMID: 26157987 PMCID: PMC4478873 DOI: 10.1117/1.nph.2.1.015008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 02/20/2015] [Indexed: 05/04/2023]
Abstract
Computing microvascular cerebral blood flow ([Formula: see text]) in real cortical angiograms is challenging. Here, we investigated whether the use of Doppler optical coherence tomography (DOCT) flow measurements in individual vessel segments can help in reconstructing [Formula: see text] across the entire vasculature of a truncated cortical angiogram. A [Formula: see text] computational framework integrating DOCT measurements is presented. Simulations performed on a synthetic angiogram showed that the addition of DOCT measurements, especially close to large inflowing or outflowing vessels, reduces the impact of pressure boundary conditions and estimated vessel resistances resulting in a more accurate reconstruction of [Formula: see text]. Our technique was then applied to reconstruct microvascular flow distributions in the mouse cortex down to [Formula: see text] by combining two-photon laser scanning microscopy angiography with DOCT.
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Affiliation(s)
- Louis Gagnon
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Building 149 13th Street, Charlestown, Massachusetts 02129, United States
- Harvard-MIT Division of Health Sciences and Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Ecole Polytechnique de Montreal, Department of Electrical Engineering, 2900 Boulevard Edouard-Montpetit, Montreal, Quebec H3T 1J4, Canada
- Address all correspondence to: Louis Gagnon, E-mail:
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Building 149 13th Street, Charlestown, Massachusetts 02129, United States
| | - Fréderic Lesage
- Ecole Polytechnique de Montreal, Department of Electrical Engineering, 2900 Boulevard Edouard-Montpetit, Montreal, Quebec H3T 1J4, Canada
| | - Emiri T. Mandeville
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Building 149 13th Street, Charlestown, Massachusetts 02129, United States
| | - Qianqian Fang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Building 149 13th Street, Charlestown, Massachusetts 02129, United States
| | - Mohammad A. Yaseen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Building 149 13th Street, Charlestown, Massachusetts 02129, United States
| | - David A. Boas
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Building 149 13th Street, Charlestown, Massachusetts 02129, United States
- Harvard-MIT Division of Health Sciences and Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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40
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You J, Du C, Volkow ND, Pan Y. Optical coherence Doppler tomography for quantitative cerebral blood flow imaging. BIOMEDICAL OPTICS EXPRESS 2014; 5:3217-30. [PMID: 25401033 PMCID: PMC4230874 DOI: 10.1364/boe.5.003217] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 07/28/2014] [Accepted: 08/04/2014] [Indexed: 05/03/2023]
Abstract
Optical coherence Doppler tomography (ODT) is a promising neurotechnique that permits 3D imaging of the cerebral blood flow (CBF) network; however, quantitative CBF velocity (CBFv) imaging remains challenging. Here we present a simple phase summation method to enhance slow capillary flow detection sensitivity without sacrificing dynamic range for fast flow and vessel tracking to improve angle correction for absolute CBFv quantification. Flow phantom validation indicated that the CBFv quantification accuracy increased from 15% to 91% and the coefficient of variation (CV) decreased 9.3-fold; in vivo mouse brain validation showed that CV decreased 4.4-/10.8- fold for venular/arteriolar flows. ODT was able to identify cocaine-elicited microischemia and quantify CBFv disruption in branch vessels and capillaries that otherwise would have not been possible.
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Affiliation(s)
- Jiang You
- Department of Biomedical Engineering Stony Brook University, Stony Brook, NY 11794, USA
| | - Congwu Du
- Department of Biomedical Engineering Stony Brook University, Stony Brook, NY 11794, USA
| | - Nora D. Volkow
- National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yingtian Pan
- Department of Biomedical Engineering Stony Brook University, Stony Brook, NY 11794, USA
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41
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Bouwens A, Bolmont T, Szlag D, Berclaz C, Lasser T. Quantitative cerebral blood flow imaging with extended-focus optical coherence microscopy. OPTICS LETTERS 2014; 39:37-40. [PMID: 24365816 DOI: 10.1364/ol.39.000037] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Quantitative three-dimensional blood flow imaging is a valuable technique to investigate the physiology of the brain. Two-photon microscopy (2PM) allows quantification of the local blood flow velocity with micrometric resolution by performing repeated line scans, but prohibitively long measurement times would be required to apply this technique to full three-dimensional volumes. By multiplexing the image acquisition over depth, Fourier domain optical coherence tomography (FDOCT) enables quantification of blood flow velocities with a high volume acquisition rate, albeit at a relatively low spatial resolution. Extended-focus optical coherence microscopy (xfOCM) increases the lateral resolution without sacrificing depth of field and therefore combines the high volume acquisition rate of FDOCT with a resolution comparable to 2PM. Here, we demonstrate high-resolution quantitative imaging of the blood flow velocity vector's magnitude in the adult murine brain with xfOCM.
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42
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Liu J, Wang Y, Akamatsu Y, Lee CC, Stetler RA, Lawton MT, Yang GY. Vascular remodeling after ischemic stroke: mechanisms and therapeutic potentials. Prog Neurobiol 2013; 115:138-56. [PMID: 24291532 DOI: 10.1016/j.pneurobio.2013.11.004] [Citation(s) in RCA: 247] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Revised: 11/14/2013] [Accepted: 11/16/2013] [Indexed: 12/18/2022]
Abstract
The brain vasculature has been increasingly recognized as a key player that directs brain development, regulates homeostasis, and contributes to pathological processes. Following ischemic stroke, the reduction of blood flow elicits a cascade of changes and leads to vascular remodeling. However, the temporal profile of vascular changes after stroke is not well understood. Growing evidence suggests that the early phase of cerebral blood volume (CBV) increase is likely due to the improvement in collateral flow, also known as arteriogenesis, whereas the late phase of CBV increase is attributed to the surge of angiogenesis. Arteriogenesis is triggered by shear fluid stress followed by activation of endothelium and inflammatory processes, while angiogenesis induces a number of pro-angiogenic factors and circulating endothelial progenitor cells (EPCs). The status of collaterals in acute stroke has been shown to have several prognostic implications, while the causal relationship between angiogenesis and improved functional recovery has yet to be established in patients. A number of interventions aimed at enhancing cerebral blood flow including increasing collateral recruitment are under clinical investigation. Transplantation of EPCs to improve angiogenesis is also underway. Knowledge in the underlying physiological mechanisms for improved arteriogenesis and angiogenesis shall lead to more effective therapies for ischemic stroke.
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Affiliation(s)
- Jialing Liu
- Department of Neurological Surgery, UCSF, San Francisco, CA 94121, USA; SFVAMC, San Francisco, CA 94121, USA.
| | - Yongting Wang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute, Shanghai 200030, China; School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China; Department of Neurology, Shanghai Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China
| | - Yosuke Akamatsu
- Department of Neurological Surgery, UCSF, San Francisco, CA 94121, USA; SFVAMC, San Francisco, CA 94121, USA; Department of Neurological Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Chih Cheng Lee
- Department of Neurological Surgery, UCSF, San Francisco, CA 94121, USA; SFVAMC, San Francisco, CA 94121, USA
| | - R Anne Stetler
- Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Michael T Lawton
- Department of Neurological Surgery, UCSF, San Francisco, CA 94121, USA
| | - Guo-Yuan Yang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute, Shanghai 200030, China; School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China; Department of Neurology, Shanghai Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China.
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43
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Srinivasan VJ, Mandeville ET, Can A, Blasi F, Climov M, Daneshmand A, Lee JH, Yu E, Radhakrishnan H, Lo EH, Sakadžić S, Eikermann-Haerter K, Ayata C. Multiparametric, longitudinal optical coherence tomography imaging reveals acute injury and chronic recovery in experimental ischemic stroke. PLoS One 2013; 8:e71478. [PMID: 23940761 PMCID: PMC3737090 DOI: 10.1371/journal.pone.0071478] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2013] [Accepted: 06/28/2013] [Indexed: 11/19/2022] Open
Abstract
Progress in experimental stroke and translational medicine could be accelerated by high-resolution in vivo imaging of disease progression in the mouse cortex. Here, we introduce optical microscopic methods that monitor brain injury progression using intrinsic optical scattering properties of cortical tissue. A multi-parametric Optical Coherence Tomography (OCT) platform for longitudinal imaging of ischemic stroke in mice, through thinned-skull, reinforced cranial window surgical preparations, is described. In the acute stages, the spatiotemporal interplay between hemodynamics and cell viability, a key determinant of pathogenesis, was imaged. In acute stroke, microscopic biomarkers for eventual infarction, including capillary non-perfusion, cerebral blood flow deficiency, altered cellular scattering, and impaired autoregulation of cerebral blood flow, were quantified and correlated with histology. Additionally, longitudinal microscopy revealed remodeling and flow recovery after one week of chronic stroke. Intrinsic scattering properties serve as reporters of acute cellular and vascular injury and recovery in experimental stroke. Multi-parametric OCT represents a robust in vivo imaging platform to comprehensively investigate these properties.
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Affiliation(s)
- Vivek J Srinivasan
- Biomedical Engineering Department, University of California Davis, Davis, California, United States of America.
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44
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Radhakrishnan H, Srinivasan VJ. Compartment-resolved imaging of cortical functional hyperemia with OCT angiography. BIOMEDICAL OPTICS EXPRESS 2013; 4:1255-68. [PMID: 24009990 PMCID: PMC3756578 DOI: 10.1364/boe.4.001255] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 06/10/2013] [Accepted: 06/13/2013] [Indexed: 05/19/2023]
Abstract
Optical Coherence Tomography (OCT) angiography was applied to image functional hyperemia in different vascular compartments in the rat somatosensory cortex. Dynamic backscattering changes, indicative of changes in dynamic red blood cell (dRBC) content, were used to monitor the hemodynamic response. Three-dimensional movies depicting the microvascular response to neuronal activation were created for the first time. An increase in the attenuation coefficient during activation was identified, and a simple normalization procedure was proposed to correct for it. This procedure was applied to determine compartment-resolved backscattering changes caused by dRBC content changes during functional activation. Increases in dRBC content were observed in all vascular compartments (arterial, arteriolar, capillary, and venular), with the largest responses found in the arterial and arteriolar compartments. dRBC content increased with dilation in arteries but with barely detectable dilation in veins. dRBC content increased in capillaries without significant "all or none" capillary recruitment.
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Affiliation(s)
- Harsha Radhakrishnan
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA
| | - Vivek J. Srinivasan
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA
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45
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Takahashi H, Sugiyama T, Tokushige H, Maeno T, Nakazawa T, Ikeda T, Araie M. Comparison of CCD-equipped laser speckle flowgraphy with hydrogen gas clearance method in the measurement of optic nerve head microcirculation in rabbits. Exp Eye Res 2012; 108:10-5. [PMID: 23262066 DOI: 10.1016/j.exer.2012.12.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Revised: 12/09/2012] [Accepted: 12/10/2012] [Indexed: 11/29/2022]
Abstract
The aim of this study was to verify the correlation between mean blur rate (MBR) obtained with CCD-equipped laser speckle flowgraphy (LSFG) and capillary blood flow (CBF) obtained by the hydrogen gas clearance method in rabbit optic nerve head (ONH). Using Japanese white rabbits under systemic anesthesia, a hydrogen electrode was inserted an area of the ONH free from superficial capillaries. MBR was measured with LSFG near the hydrogen electrode. CBF and MBR were measured in the range of 32.4-83.5 mL/min/100 g and 3.5-6.0, respectively. MBR and CBF were significantly correlated (r = 0.73, P < 0.01, n = 14). After inhalation of carbon dioxide (CO(2)) or intravenous administration of endothelin-1 (ET-1), MBR and CBF were changed in the relative range of 0.74-1.27 and 0.76-1.35, respectively. The relative changes in MBR and CBF induced by CO(2) and ET-1 were also significantly correlated (r = 0.67, P < 0.01). The current results suggest that MBR may correlate with CBF and also change with CBF, as an index of blood flow in the ONH, linearly.
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Affiliation(s)
- Hiroaki Takahashi
- Research Laboratory for Drug Development, Senju Pharmaceutical Co., Ltd., 1-5-4 Murotani, Nishi-ku, Kobe, Hyogo 651-2241, Japan
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46
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Devor A, Sakadžić S, Srinivasan VJ, Yaseen MA, Nizar K, Saisan PA, Tian P, Dale AM, Vinogradov SA, Franceschini MA, Boas DA. Frontiers in optical imaging of cerebral blood flow and metabolism. J Cereb Blood Flow Metab 2012; 32:1259-76. [PMID: 22252238 PMCID: PMC3390808 DOI: 10.1038/jcbfm.2011.195] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In vivo optical imaging of cerebral blood flow (CBF) and metabolism did not exist 50 years ago. While point optical fluorescence and absorption measurements of cellular metabolism and hemoglobin concentrations had already been introduced by then, point blood flow measurements appeared only 40 years ago. The advent of digital cameras has significantly advanced two-dimensional optical imaging of neuronal, metabolic, vascular, and hemodynamic signals. More recently, advanced laser sources have enabled a variety of novel three-dimensional high-spatial-resolution imaging approaches. Combined, as we discuss here, these methods are permitting a multifaceted investigation of the local regulation of CBF and metabolism with unprecedented spatial and temporal resolution. Through multimodal combination of these optical techniques with genetic methods of encoding optical reporter and actuator proteins, the future is bright for solving the mysteries of neurometabolic and neurovascular coupling and translating them to clinical utility.
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Affiliation(s)
- Anna Devor
- Department of Neurosciences, UCSD, La Jolla, CA, USA.
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47
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Shih AY, Driscoll JD, Drew PJ, Nishimura N, Schaffer CB, Kleinfeld D. Two-photon microscopy as a tool to study blood flow and neurovascular coupling in the rodent brain. J Cereb Blood Flow Metab 2012; 32:1277-309. [PMID: 22293983 PMCID: PMC3390800 DOI: 10.1038/jcbfm.2011.196] [Citation(s) in RCA: 308] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 10/18/2011] [Accepted: 11/13/2011] [Indexed: 01/09/2023]
Abstract
The cerebral vascular system services the constant demand for energy during neuronal activity in the brain. Attempts to delineate the logic of neurovascular coupling have been greatly aided by the advent of two-photon laser scanning microscopy to image both blood flow and the activity of individual cells below the surface of the brain. Here we provide a technical guide to imaging cerebral blood flow in rodents. We describe in detail the surgical procedures required to generate cranial windows for optical access to the cortex of both rats and mice and the use of two-photon microscopy to accurately measure blood flow in individual cortical vessels concurrent with local cellular activity. We further provide examples on how these techniques can be applied to the study of local blood flow regulation and vascular pathologies such as small-scale stroke.
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Affiliation(s)
- Andy Y Shih
- Department of Physics, University of California at San Diego, La Jolla, California, USA
| | - Jonathan D Driscoll
- Department of Physics, University of California at San Diego, La Jolla, California, USA
| | - Patrick J Drew
- Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania, USA
- Department of Neurosurgery, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Nozomi Nishimura
- Department of Biomedical Engineering, Cornell University, Ithaca, New York, USA
| | - Chris B Schaffer
- Department of Biomedical Engineering, Cornell University, Ithaca, New York, USA
| | - David Kleinfeld
- Department of Physics, University of California at San Diego, La Jolla, California, USA
- Section of Neurobiology, University of California at San Diego, La Jolla, California, USA
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Kim TN, Goodwill PW, Chen Y, Conolly SM, Schaffer CB, Liepmann D, Wang RA. Line-scanning particle image velocimetry: an optical approach for quantifying a wide range of blood flow speeds in live animals. PLoS One 2012; 7:e38590. [PMID: 22761686 PMCID: PMC3383695 DOI: 10.1371/journal.pone.0038590] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 05/10/2012] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND The ability to measure blood velocities is critical for studying vascular development, physiology, and pathology. A key challenge is to quantify a wide range of blood velocities in vessels deep within living specimens with concurrent diffraction-limited resolution imaging of vascular cells. Two-photon laser scanning microscopy (TPLSM) has shown tremendous promise in analyzing blood velocities hundreds of micrometers deep in animals with cellular resolution. However, current analysis of TPLSM-based data is limited to the lower range of blood velocities and is not adequate to study faster velocities in many normal or disease conditions. METHODOLOGY/PRINCIPAL FINDINGS We developed line-scanning particle image velocimetry (LS-PIV), which used TPLSM data to quantify peak blood velocities up to 84 mm/s in live mice harboring brain arteriovenous malformation, a disease characterized by high flow. With this method, we were able to accurately detect the elevated blood velocities and exaggerated pulsatility along the abnormal vascular network in these animals. LS-PIV robustly analyzed noisy data from vessels as deep as 850 µm below the brain surface. In addition to analyzing in vivo data, we validated the accuracy of LS-PIV up to 800 mm/s using simulations with known velocity and noise parameters. CONCLUSIONS/SIGNIFICANCE To our knowledge, these blood velocity measurements are the fastest recorded with TPLSM. Partnered with transgenic mice carrying cell-specific fluorescent reporters, LS-PIV will also enable the direct in vivo correlation of cellular, biochemical, and hemodynamic parameters in high flow vascular development and diseases such as atherogenesis, arteriogenesis, and vascular anomalies.
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Affiliation(s)
- Tyson N. Kim
- Laboratory for Accelerated Vascular Research, Division of Vascular Surgery, Department of Surgery, University of California San Francisco, San Francisco, California, United States of America
| | - Patrick W. Goodwill
- Department of Bioengineering, University of California, Berkeley, California, United States of America
| | - Yeni Chen
- Laboratory for Accelerated Vascular Research, Division of Vascular Surgery, Department of Surgery, University of California San Francisco, San Francisco, California, United States of America
| | - Steven M. Conolly
- Department of Bioengineering, University of California, Berkeley, California, United States of America
| | - Chris B. Schaffer
- Department of Biomedical Engineering, Cornell University, Ithaca, New York, United States of America
| | - Dorian Liepmann
- Department of Bioengineering, University of California, Berkeley, California, United States of America
| | - Rong A. Wang
- Laboratory for Accelerated Vascular Research, Division of Vascular Surgery, Department of Surgery, University of California San Francisco, San Francisco, California, United States of America
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Abstract
The review provides a concise explanation of principles of operation of different optical coherence tomography methods. A comparative analysis of their advantages and disadvantages is presented in relation to specific applications. The review will assist the reader in making an educated choice on the most suitable optical coherence tomography method to be used in a particular application.
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Affiliation(s)
- A Gh Podoleanu
- School of Physical Sciences, University of Kent, Canterbury, UK.
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Cadotte DW, Mariampillai A, Cadotte A, Lee KKC, Kiehl TR, Wilson BC, Fehlings MG, Yang VXD. Speckle variance optical coherence tomography of the rodent spinal cord: in vivo feasibility. BIOMEDICAL OPTICS EXPRESS 2012; 3:911-919. [PMID: 22567584 PMCID: PMC3342196 DOI: 10.1364/boe.3.000911] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 03/24/2012] [Accepted: 03/31/2012] [Indexed: 05/29/2023]
Abstract
Optical coherence tomography (OCT) has the combined advantage of high temporal (µsec) and spatial (<10µm) resolution. These features make it an attractive tool to study the dynamic relationship between neural activity and the surrounding blood vessels in the spinal cord, a topic that is poorly understood. Here we present work that aims to optimize an in vivo OCT imaging model of the rodent spinal cord. In this study we image the microvascular networks of both rats and mice using speckle variance OCT. This is the first report of depth resolved imaging of the in vivo spinal cord using an entirely endogenous contrast mechanism.
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Affiliation(s)
- David W. Cadotte
- Division of Neurosurgery, Toronto Western Hospital, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
- These authors contributed equally to this work
| | - Adrian Mariampillai
- Biophotonics and Bioengineering Laboratory, Ryerson University, Toronto, Ontario, Canada
- Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada
- These authors contributed equally to this work
| | - Adam Cadotte
- Division of Neurosurgery, Toronto Western Hospital, Toronto, Ontario, Canada
- Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - Kenneth K. C. Lee
- Biophotonics and Bioengineering Laboratory, Ryerson University, Toronto, Ontario, Canada
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Tim-Rasmus Kiehl
- Department of Pathology, University of Toronto, Toronto, Ontario, Canada
| | - Brian C. Wilson
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Michael G. Fehlings
- Division of Neurosurgery, Toronto Western Hospital, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - Victor X. D. Yang
- Biophotonics and Bioengineering Laboratory, Ryerson University, Toronto, Ontario, Canada
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada
- Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada
- Department of Medical Imaging, St. Michael’s Hospital, Toronto, Ontario, Canada
- Division of Neurosurgery, St. Michael’s Hospital, Toronto, Ontario, Canada
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