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Cannon TM, Bouma BE, Uribe-Patarroyo N. Mapping optical scattering properties to physical particle information in singly and multiply scattering samples. BIOMEDICAL OPTICS EXPRESS 2023; 14:4326-4348. [PMID: 37799686 PMCID: PMC10549752 DOI: 10.1364/boe.494518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 07/10/2023] [Accepted: 07/19/2023] [Indexed: 10/07/2023]
Abstract
Optical coherence tomography (OCT) leverages light scattering by biological tissues as endogenous contrast to form structural images. Light scattering behavior is dictated by the optical properties of the tissue, which depend on microstructural details at the cellular or sub-cellular level. Methods to measure these properties from OCT intensity data have been explored in the context of a number of biomedical applications seeking to access this sub-resolution tissue microstructure and thereby increase the diagnostic impact of OCT. Most commonly, the optical attenuation coefficient, an analogue of the scattering coefficient, has been used as a surrogate metric linking OCT intensity to subcellular particle characteristics. To record attenuation coefficient data that is accurately representative of the underlying physical properties of a given sample, it is necessary to account for the impact of the OCT imaging system itself on the distribution of light intensity in the sample, including the numerical aperture (NA) of the system and the location of the focal plane with respect to the sample surface, as well as the potential contribution of multiple scattering to the reconstructed intensity signal. Although these considerations complicate attenuation coefficient measurement and interpretation, a suitably calibrated system may potentiate a powerful strategy for gaining additional information about the scattering behavior and microstructure of samples. In this work, we experimentally show that altering the OCT system geometry minimally impacts measured attenuation coefficients in samples presumed to be singly scattering, but changes these measurements in more highly scattering samples. Using both depth-resolved attenuation coefficient data and layer-resolved backscattering coefficients, we demonstrate the retrieval of scattering particle diameter and concentration in tissue-mimicking phantoms, and the impact of presumed multiple scattering on these calculations. We further extend our approach to characterize a murine brain tissue sample and highlight a tumor-bearing region based on increased scattering particle density. Through these methods, we not only enhance conventional OCT attenuation coefficient analysis by decoupling the independent effects of particle size and concentration, but also discriminate areas of strong multiple scattering through minor changes to system topology to provide a framework for assessing the accuracy of these measurements.
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Affiliation(s)
- Taylor M. Cannon
- Massachusetts Institute of Technology, Institute of Medical Engineering and Science, 70 Massachusetts Avenue, Cambridge, MA 02141, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, 40 Blossom St, Boston, MA 02114, USA
| | - Brett E. Bouma
- Massachusetts Institute of Technology, Institute of Medical Engineering and Science, 70 Massachusetts Avenue, Cambridge, MA 02141, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, 40 Blossom St, Boston, MA 02114, USA
| | - Néstor Uribe-Patarroyo
- Wellman Center for Photomedicine, Massachusetts General Hospital, 40 Blossom St, Boston, MA 02114, USA
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2
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Rosen G, Kirsch D, Horowitz S, Cherry JD, Nicks R, Kelley H, Uretsky M, Dell'Aquila K, Mathias R, Cormier KA, Kubilus CA, Mez J, Tripodis Y, Stein TD, Alvarez VE, Alosco ML, McKee AC, Huber BR. Three dimensional evaluation of cerebrovascular density and branching in chronic traumatic encephalopathy. Acta Neuropathol Commun 2023; 11:123. [PMID: 37491342 PMCID: PMC10369801 DOI: 10.1186/s40478-023-01612-y] [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: 06/26/2023] [Accepted: 06/28/2023] [Indexed: 07/27/2023] Open
Abstract
Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with exposure to repetitive head impacts (RHI) and characterized by perivascular accumulations of hyperphosphorylated tau protein (p-tau) at the depths of the cortical sulci. Studies of living athletes exposed to RHI, including concussive and nonconcussive impacts, have shown increased blood-brain barrier permeability, reduced cerebral blood flow, and alterations in vasoreactivity. Blood-brain barrier abnormalities have also been reported in individuals neuropathologically diagnosed with CTE. To further investigate the three-dimensional microvascular changes in individuals diagnosed with CTE and controls, we used SHIELD tissue processing and passive delipidation to optically clear and label blocks of postmortem human dorsolateral frontal cortex. We used fluorescent confocal microscopy to quantitate vascular branch density and fraction volume. We compared the findings in 41 male brain donors, age at death 31-89 years, mean age 64 years, including 12 donors with low CTE (McKee stage I-II), 13 with high CTE (McKee stage III-IV) to 16 age- and sex-matched non-CTE controls (7 with RHI exposure and 9 with no RHI exposure). The density of vessel branches in the gray matter sulcus was significantly greater in CTE cases than in controls. The ratios of sulcus versus gyrus vessel branch density and fraction volume were also greater in CTE than in controls and significantly above one for the CTE group. Hyperphosphorylated tau pathology density correlated with gray matter sulcus fraction volume. These findings point towards increased vascular coverage and branching in the dorsolateral frontal cortex (DLF) sulci in CTE, that correlates with p-tau pathology.
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Affiliation(s)
- Grace Rosen
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA
- National Center for PTSD, US Department of Veterans Affairs, Boston, MA, USA
| | - Daniel Kirsch
- Department of Pathology and Laboratory Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
| | - Sarah Horowitz
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA
- National Center for PTSD, US Department of Veterans Affairs, Boston, MA, USA
| | - Jonathan D Cherry
- Department of Pathology and Laboratory Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Raymond Nicks
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Hunter Kelley
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Madeline Uretsky
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Kevin Dell'Aquila
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Rebecca Mathias
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
| | - Kerry A Cormier
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
- VA Bedford Healthcare System, US Department of Veterans Affairs, Bedford, MA, USA
| | - Caroline A Kubilus
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
- VA Bedford Healthcare System, US Department of Veterans Affairs, Bedford, MA, USA
| | - Jesse Mez
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Yorghos Tripodis
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
- Department of Biostatistics, Boston University School of Public Health, Boston, USA
| | - Thor D Stein
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA
- Department of Pathology and Laboratory Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Victor E Alvarez
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA
- Department of Pathology and Laboratory Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Michael L Alosco
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Ann C McKee
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA
- Department of Pathology and Laboratory Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
- VA Bedford Healthcare System, US Department of Veterans Affairs, Bedford, MA, USA
| | - Bertrand R Huber
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA.
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA.
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA.
- National Center for PTSD, US Department of Veterans Affairs, Boston, MA, USA.
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Guo X, Ren G, Tang J. Autocorrelation analysis-based OCT velocimetry for axial blood flow velocity imaging of the cerebral capillary network. OPTICS LETTERS 2023; 48:3599-3602. [PMID: 37390190 DOI: 10.1364/ol.493011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 06/03/2023] [Indexed: 07/02/2023]
Abstract
The accurate measurement of blood flow velocity in the capillary network is challenging due to the small size of the vessels and the slow flow of red blood cells (RBCs) within the vessel. Here, we introduce an autocorrelation analysis-based optical coherence tomography (OCT) method that takes less acquisition time to measure the axial blood flow velocity in the capillary network. The axial blood flow velocity was obtained from the phase change in the decorrelation period of the first-order field autocorrelation function (g1) of the OCT field data, which was acquired with M-mode acquisition (repeated A-scans). The rotation center of g1 in the complex plane was first re-centralized to the origin, then the phase change due to the movement of RBCs was extracted in the g1 decorrelation period which is usually 0.2-0.5 ms. In phantom experiments, the results suggest that the proposed method could accurately measure the axial speed with a wide range of 0.5-15 mm/s. We further tested the method on living animals. Compared with the phase-resolved Doppler optical coherence tomography (pr-DOCT), the proposed method can obtain robust axial velocity measurements with more than five times shorter acquisition time.
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Staehr C, Giblin JT, Gutiérrez‐Jiménez E, Guldbrandsen HØ, Tang J, Sandow SL, Boas DA, Matchkov VV. Neurovascular Uncoupling Is Linked to Microcirculatory Dysfunction in Regions Outside the Ischemic Core Following Ischemic Stroke. J Am Heart Assoc 2023; 12:e029527. [PMID: 37232244 PMCID: PMC10381981 DOI: 10.1161/jaha.123.029527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 04/19/2023] [Indexed: 05/27/2023]
Abstract
Background Normal brain function depends on the ability of the vasculature to increase blood flow to regions with high metabolic demands. Impaired neurovascular coupling, such as the local hyperemic response to neuronal activity, may contribute to poor neurological outcome after stroke despite successful recanalization, that is, futile recanalization. Methods and Results Mice implanted with chronic cranial windows were trained for awake head-fixation before experiments. One-hour occlusion of the anterior middle cerebral artery branch was induced using single-vessel photothrombosis. Cerebral perfusion and neurovascular coupling were assessed by optical coherence tomography and laser speckle contrast imaging. Capillaries and pericytes were studied in perfusion-fixed tissue by labeling lectin and platelet-derived growth factor receptor β. Arterial occlusion induced multiple spreading depolarizations over 1 hour associated with substantially reduced blood flow in the peri-ischemic cortex. Approximately half of the capillaries in the peri-ischemic area were no longer perfused at the 3- and 24-hour follow-up (45% [95% CI, 33%-58%] and 53% [95% CI, 39%-66%] reduction, respectively; P<0.0001), which was associated with contraction of an equivalent proportion of peri-ischemic capillary pericytes. The capillaries in the peri-ischemic cortex that remained perfused showed increased point prevalence of dynamic flow stalling (0.5% [95% CI, 0.2%-0.7%] at baseline, 5.1% [95% CI, 3.2%-6.5%] and 3.2% [95% CI, 1.1%-5.3%] at 3- and 24-hour follow-up, respectively; P=0.001). Whisker stimulation at the 3- and 24-hour follow-up led to reduced neurovascular coupling responses in the sensory cortex corresponding to the peri-ischemic region compared with that observed at baseline. Conclusions Arterial occlusion led to contraction of capillary pericytes and capillary flow stalling in the peri-ischemic cortex. Capillary dysfunction was associated with neurovascular uncoupling. Neurovascular coupling impairment associated with capillary dysfunction may be a mechanism that contributes to futile recanalization. Hence, the results from this study suggest a novel treatment target to improve neurological outcome after stroke.
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Affiliation(s)
- Christian Staehr
- Department of BiomedicineAarhus UniversityAarhusDenmark
- Neurophotonics Center, Department of Biomedical EngineeringBoston UniversityBostonMAUSA
| | - John T. Giblin
- Neurophotonics Center, Department of Biomedical EngineeringBoston UniversityBostonMAUSA
| | - Eugenio Gutiérrez‐Jiménez
- Center of Functionally Integrative Neuroscience, Institute for Clinical MedicineAarhus UniversityAarhusDenmark
| | | | - Jianbo Tang
- Neurophotonics Center, Department of Biomedical EngineeringBoston UniversityBostonMAUSA
- Department of Biomedical EngineeringSouthern University of Science and TechnologyShenzhenChina
| | - Shaun L. Sandow
- Biomedical Science, School of HealthUniversity of the Sunshine CoastSippy DownsAustralia
- Centre for Clinical Research, Faculty of MedicineThe University of QueenslandBrisbaneAustralia
| | - David A. Boas
- Neurophotonics Center, Department of Biomedical EngineeringBoston UniversityBostonMAUSA
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Yang C, Yao L, Zhou L, Qian S, Meng J, Yang L, Chen L, Tan Y, Qiu H, Gu Y, Ding Z, Li P, Liu Z. Mapping port wine stain in vivo by optical coherence tomography angiography and multi-metric characterization. OPTICS EXPRESS 2023; 31:13613-13626. [PMID: 37157245 DOI: 10.1364/oe.485619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Port wine stain (PWS) is a congenital cutaneous capillary malformation composed of ecstatic vessels, while the microstructure of these vessels remains largely unknown. Optical coherence tomography angiography (OCTA) serves as a non-invasive, label-free and high-resolution tool to visualize the 3D tissue microvasculature. However, even as the 3D vessel images of PWS become readily accessible, quantitative analysis algorithms for their organization have mainly remained limited to analysis of 2D images. Especially, 3D orientations of vasculature in PWS have not yet been resolved at a voxel-wise basis. In this study, we employed the inverse signal-to-noise ratio (iSNR)-decorrelation (D) OCTA (ID-OCTA) to acquire 3D blood vessel images in vivo from PWS patients, and used the mean-subtraction method for de-shadowing to correct the tail artifacts. We developed algorithms which mapped blood vessels in spatial-angular hyperspace in a 3D context, and obtained orientation-derived metrics including directional variance and waviness for the characterization of vessel alignment and crimping level, respectively. Combining with thickness and local density measures, our method served as a multi-parametric analysis platform which covered a variety of morphological and organizational characteristics at a voxel-wise basis. We found that blood vessels were thicker, denser and less aligned in lesion skin in contrast to normal skin (symmetrical parts of skin lesions on the cheek), and complementary insights from these metrics led to a classification accuracy of ∼90% in identifying PWS. An improvement in sensitivity of 3D analysis was validated over 2D analysis. Our imaging and analysis system provides a clear picture of the microstructure of blood vessels within PWS tissues, which leads to a better understanding of this capillary malformation disease and facilitates improvements in diagnosis and treatment of PWS.
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Zhou J, Li Y, Tang J. Adaptive dynamic analysis-based optical coherence tomography angiography for blood vessel projection artifact suppression. BIOMEDICAL OPTICS EXPRESS 2023; 14:477-488. [PMID: 36698660 PMCID: PMC9842011 DOI: 10.1364/boe.469891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 12/11/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
Optical coherence tomography angiography (OCTA) for blood vessel 3-D structure imaging suffers from blood vessel projection artifacts/tail artifacts when using a long decorrelation time (e.g., repeat B-scan acquisition in regular OCTA) or loss of micro vessel signal when using a short decorrelation time. In this work, we developed an adaptive first-order field autocorrelation function (g1) analysis-based technique to suppress the projection artifacts under macro vessels while enhancing the dynamic signal of micro vessels. The proposed method is based on the differences of the decorrelation rate and the phase variations of g1 between the vessel voxels and the artifacts regions. A short or long decorrelation time was applied to obtain the dynamic index of the projection artifacts region or the blood vessel region, respectively. Compared to the slab subtraction-based post-image processing-based techniques, the proposed approach addresses this problem on a physical basis and shows the ability to suppress the projection artifacts while enhancing the detection of the micro vessels.
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Affiliation(s)
- Junxiong Zhou
- Guangdong Provincial Key Laboratory of Advanced Biomaterials, Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
- Contributed equally
| | - Yuntao Li
- Guangdong Provincial Key Laboratory of Advanced Biomaterials, Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
- Department of Bioengineering, Northeastern University, Boston, Massachusetts 02115, USA
- Contributed equally
| | - Jianbo Tang
- Guangdong Provincial Key Laboratory of Advanced Biomaterials, Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
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Novel Elastography-Inspired Approach to Angiographic Visualization in Optical Coherence Tomography. PHOTONICS 2022. [DOI: 10.3390/photonics9060401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
In this paper, we present a new approach to contrast-agent-free angiographic visualization in optical coherence tomography (OCT). The proposed approach has much in common with imaging of local interframe strains in OCT-based elastography and utilizes the fact that the interframe motion of blood particles leads to discontinuity of strains within the vessel cross section. By this reasoning, we call this approach “elastography-inspired”. Here, we first elucidate the essence and main features of the elastography-inspired approach using numerical simulation of OCT data. The simulations allow one to introduce both moving scatterers imitating blood flow in vessels as well as various masking motions imitating natural motions of living “solid” tissue surrounding the vessels. Second, using real OCT signals, we present comparative results of angiographic processing using the proposed elastography-inspired approach and a realization of OCA based on high-pass filtering of temporal variability of a series of OCT B-scans. The two methods can use the same initial dataset and the high-pass filtering OCA has already been routinely applied in both animal experiments and on patients. The new elastography-inspired method has a similar computational efficiency, and it is intrinsically able to compensate spatially-inhomogeneous masking tissue motions and demonstrates high robustness with respect to motion artefacts. Thus, the new approach looks very promising for enabling wider application of OCA in both laboratory studies on animals and, most importantly, for wider clinical applications on patients.
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8
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Cannon TM, Bouma BE, Uribe-Patarroyo N. Layer-based, depth-resolved computation of attenuation coefficients and backscattering fractions in tissue using optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2021; 12:5037-5056. [PMID: 34513241 PMCID: PMC8407832 DOI: 10.1364/boe.427833] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/06/2021] [Accepted: 07/11/2021] [Indexed: 05/18/2023]
Abstract
Structural optical coherence tomography (OCT) images of tissue stand to benefit from greater functionalization and quantitative interpretation. The OCT attenuation coefficient µ, an analogue of the imaged sample's scattering coefficient, offers potential functional contrast based on the relationship of µ to sub-resolution physical properties of the sample. Attenuation coefficients are computed either by fitting a representative µ over several depth-wise pixels of a sample's intensity decay, or by using previously-developed depth-resolved attenuation algorithms by Girard et al. [Invest. Ophthalmol. Vis. Sci.52, 7738 (2011). 10.1167/iovs.10-6925] and Vermeer et al. [Biomed. Opt. Express5, 322 (2014). 10.1364/BOE.5.000322]. However, the former method sacrifices axial information in the tomogram, while the latter relies on the stringent assumption that the sample's backscattering fraction, another optical property, does not vary along depth. This assumption may be violated by layered tissues commonly observed in clinical imaging applications. Our approach preserves the full depth resolution of the attenuation map but removes its dependence on backscattering fraction by performing signal analysis inside individual discrete layers over which the scattering properties (e.g., attenuation and backscattering fraction) vary minimally. Although this approach necessitates the detection of these layers, it removes the constant-backscattering-fraction assumption that has constrained quantitative attenuation coefficient analysis in the past, and additionally yields a layer-resolved backscattering fraction, providing complementary scattering information to the attenuation coefficient. We validate our approach using automated layer detection in layered phantoms, for which the measured optical properties were in good agreement with theoretical values calculated with Mie theory, and show preliminary results in tissue alongside corresponding histological analysis. Together, accurate backscattering fraction and attenuation coefficient measurements enable the estimation of both particle density and size, which is not possible from attenuation measurements alone. We hope that this improvement to depth-resolved attenuation coefficient measurement, augmented by a layer-resolved backscattering fraction, will increase the diagnostic power of quantitative OCT imaging.
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Affiliation(s)
- Taylor M. Cannon
- Massachusetts Institute of Technology, Institute of Medical Engineering and Science, 70 Massachusetts Avenue, Cambridge, MA 02141, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, 40 Blossom St, Boston, MA 02114, USA
| | - Brett E. Bouma
- Massachusetts Institute of Technology, Institute of Medical Engineering and Science, 70 Massachusetts Avenue, Cambridge, MA 02141, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, 40 Blossom St, Boston, MA 02114, USA
| | - Néstor Uribe-Patarroyo
- Wellman Center for Photomedicine, Massachusetts General Hospital, 40 Blossom St, Boston, MA 02114, USA
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Pakdaman Zangabad R, Iskander-Rizk S, van der Meulen P, Meijlink B, Kooiman K, Wang T, van der Steen AFW, van Soest G. Photoacoustic flow velocity imaging based on complex field decorrelation. PHOTOACOUSTICS 2021; 22:100256. [PMID: 33868919 PMCID: PMC8040274 DOI: 10.1016/j.pacs.2021.100256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/16/2021] [Accepted: 02/21/2021] [Indexed: 05/18/2023]
Abstract
Photoacoustic (PA) imaging can be used to monitor flowing blood inside the microvascular and capillary bed. Ultrasound speckle decorrelation based velocimetry imaging was previously shown to accurately estimate blood flow velocity in mouse brain (micro-)vasculature. Translating this method to photoacoustic imaging will allow simultaneous imaging of flow velocity and extracting functional parameters like blood oxygenation. In this study, we use a pulsed laser diode and a quantitative method based on normalized first order field autocorrelation function of PA field fluctuations to estimate flow velocities in an ink tube phantom and in the microvasculature of the chorioallantoic membrane of a chicken embryo. We demonstrate how the decorrelation time of signals acquired over frames are related to the flow speed and show that the PA flow analysis based on this approach is an angle independent flow velocity imaging method.
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Affiliation(s)
- Reza Pakdaman Zangabad
- Biomedical Engineering, Department of Cardiology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Sophinese Iskander-Rizk
- Biomedical Engineering, Department of Cardiology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Pim van der Meulen
- Department of Microelectronics, Delft University of Technology, Delft, The Netherlands
| | - Bram Meijlink
- Biomedical Engineering, Department of Cardiology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Klazina Kooiman
- Biomedical Engineering, Department of Cardiology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Tianshi Wang
- Biomedical Engineering, Department of Cardiology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Antonius F W van der Steen
- Biomedical Engineering, Department of Cardiology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Imaging Science and Physics, Delft University of Technology, Delft, The Netherlands
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Gijs van Soest
- Biomedical Engineering, Department of Cardiology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
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10
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Stefan S, Lee J. Deep learning toolbox for automated enhancement, segmentation, and graphing of cortical optical coherence tomography microangiograms. BIOMEDICAL OPTICS EXPRESS 2020; 11:7325-7342. [PMID: 33409000 PMCID: PMC7747889 DOI: 10.1364/boe.405763] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/17/2020] [Accepted: 11/17/2020] [Indexed: 05/03/2023]
Abstract
Optical coherence tomography angiography (OCTA) is becoming increasingly popular for neuroscientific study, but it remains challenging to objectively quantify angioarchitectural properties from 3D OCTA images. This is mainly due to projection artifacts or "tails" underneath vessels caused by multiple-scattering, as well as the relatively low signal-to-noise ratio compared to fluorescence-based imaging modalities. Here, we propose a set of deep learning approaches based on convolutional neural networks (CNNs) to automated enhancement, segmentation and gap-correction of OCTA images, especially of those obtained from the rodent cortex. Additionally, we present a strategy for skeletonizing the segmented OCTA and extracting the underlying vascular graph, which enables the quantitative assessment of various angioarchitectural properties, including individual vessel lengths and tortuosity. These tools, including the trained CNNs, are made publicly available as a user-friendly toolbox for researchers to input their OCTA images and subsequently receive the underlying vascular network graph with the associated angioarchitectural properties.
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Affiliation(s)
- Sabina Stefan
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI 02912, USA
| | - Jonghwan Lee
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI 02912, USA
- Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
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11
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Genina EA, Surkov YI, Serebryakova IA, Bashkatov AN, Tuchin VV, Zharov VP. Rapid Ultrasound Optical Clearing of Human Light and Dark Skin. IEEE TRANSACTIONS ON MEDICAL IMAGING 2020; 39:3198-3206. [PMID: 32310764 DOI: 10.1109/tmi.2020.2989079] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Application of optical clearing of biological tissue in humans in vivo is challenging due to toxicity of chemical agents, long processing time (≥30 min), and moderate (1.3-1.5-fold) imaging depth improvement. Here, we introduce novel, robust, and rapid ultrasound-based optical clearing of human skin without chemical agents that provides dramatic (up to 10-fold) reducing processing time down to 2-5 min. We discovered that ultrasound alone can increase a light depth penetration for optical coherence tomography (OCT) up to ~1.5-fold during 2 min. Nevertheless, sequent application of microdermabrasion, oleic acid and ultrasound allowed increasing OCT signal amplitude up to 3.3-fold with more than twice improved depth penetration during 30 min that was not demonstrated with other approaches. Comparison of these effects in light and dark skin revealed similarity of the optical clearing mechanisms. However, for combined optical clearing, only 1.34-fold increase in OCT signal amplitude was achieved for dark skin.
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12
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Choi WJ, Paulson B, Yu S, Wang RK, Kim JK. Mean-Subtraction Method for De-shadowing of Tail Artifacts in Cerebral OCTA Images: A Proof of Concept. MATERIALS 2020; 13:ma13092024. [PMID: 32357466 PMCID: PMC7254351 DOI: 10.3390/ma13092024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/22/2020] [Accepted: 04/23/2020] [Indexed: 01/25/2023]
Abstract
When imaging brain vasculature with optical coherence tomography angiography (OCTA), volumetric analysis of cortical vascular networks in OCTA datasets is frequently challenging due to the presence of artifacts, which appear as multiple-scattering tails beneath superficial large vessels in OCTA images. These tails shadow underlying small vessels, making the assessment of vascular morphology in the deep cortex difficult. In this work, we introduce an image processing technique based on mean subtraction of the depth profile that can effectively reduce these tails to better reveal small hidden vessels compared to the current tail removal approach. With the improved vascular image quality, we demonstrate that this simple method can provide better visualization of three-dimensional vascular network topology for quantitative cerebrovascular studies.
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Affiliation(s)
- Woo June Choi
- School of Electrical and Electronics Engineering, Chung-Ang University, Seoul 06974, Korea; (W.J.C.); (S.Y.)
| | - Bjorn Paulson
- Biomedical Engineering Research Center, Asan Institute for Life Science, Asan Medical Center, Seoul 05505, Korea;
| | - Sungwook Yu
- School of Electrical and Electronics Engineering, Chung-Ang University, Seoul 06974, Korea; (W.J.C.); (S.Y.)
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA;
| | - Jun Ki Kim
- Biomedical Engineering Research Center, Asan Institute for Life Science, Asan Medical Center, Seoul 05505, Korea;
- Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul 05505, Korea
- Correspondence: ; Tel.: +82-2-3010-8619
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13
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Ferris NG, Cannon TM, Villiger M, Bouma BE, Uribe-Patarroyo N. Forward multiple scattering dominates speckle decorrelation in whole-blood flowmetry using optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2020; 11:1947-1966. [PMID: 32341859 PMCID: PMC7173878 DOI: 10.1364/boe.384539] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 03/06/2020] [Accepted: 03/06/2020] [Indexed: 05/22/2023]
Abstract
Quantitative blood flow measurements using optical coherence tomography (OCT) have a wide potential range of medical research and clinical applications. Flowmetry based on the temporal dynamics of the OCT signal may have the ability to measure three-dimensional flow profiles regardless of the flow direction. State-of-the-art models describing the OCT signal temporal statistics are based on dynamic light scattering (DLS), a model which is inherently limited to single scattering regimes. DLS methods continue to be applied to OCT despite the knowledge that red blood cells produce strong forward multiple scattering. Here, we postulate that forward multiple scattering is the primary mechanism causing the rate of speckle-decorrelation derived from data acquired in vivo to deviate from the rate of decorrelation determined in phantom experiments. We also postulate that multiple scattering contributions to decorrelation are only present when the sample exhibits velocity field inhomogeneities larger than the scale of a resolution volume and are thus absent in rigid bulk motion. To test these hypotheses, we performed a systematic study of the effects of forward multiple scattering on OCT signal decorrelation with phantom experiments under physiologically relevant flow conditions and relative bulk motion. Our experimental results confirm that the amount of forward multiple scattering affects the proportionality between lateral flow and decorrelation. We propose that multiply scattered light carries information from different locations in the sample and each location imprints scattering dynamics on the scattered light causing increased decorrelation rates. Our analysis confirms that the detection of forward scattered light inside the vessel lumen causes an increase in the rate of decorrelation which results in an overestimation of blood flow velocities at depths as shallow as 40 µm into whole blood for OCT systems with typical numerical apertures used in retinal imaging.
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Affiliation(s)
- Natalie G. Ferris
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, Massachusetts 02114, USA
- Harvard-MIT Program in Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
- Harvard Graduate Program in Biophysics, Harvard University Cambridge, Massachusetts 02139, USA
| | - Taylor M. Cannon
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, Massachusetts 02114, USA
- Harvard-MIT Program in Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
| | - Martin Villiger
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, Massachusetts 02114, USA
| | - Brett E. Bouma
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, Massachusetts 02114, USA
- Harvard-MIT Program in Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
- Institute for Medical Engineering and Science, MIT, Massachusetts 02139, USA
| | - Néstor Uribe-Patarroyo
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, Massachusetts 02114, USA
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14
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Dolezyczek H, Tamborski S, Majka P, Sampson D, Wojtkowski M, Wilczyński G, Szkulmowski M, Malinowska M. In vivo brain imaging with multimodal optical coherence microscopy in a mouse model of thromboembolic photochemical stroke. NEUROPHOTONICS 2020; 7:015002. [PMID: 32016131 PMCID: PMC6977401 DOI: 10.1117/1.nph.7.1.015002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 12/19/2019] [Indexed: 06/10/2023]
Abstract
We used a new multimodal imaging system that combines optical coherence microscopy and brightfield microscopy. Using this in vivo brain monitoring approach and cranial window implantation, we three-dimensionally visualized the vascular network during thrombosis, with high temporal (18 s) and spatial (axial, 2.5 μ m ; lateral, 2.2 μ m ) resolution. We used a modified mouse model of photochemical thromboembolic stroke in order to more accurately parallel human stroke. Specifically, we applied green laser illumination to focally occlude a branch of the middle cerebral artery. Despite the recanalization of the superficial arteries at 24 h after stroke, no blood flow was detected in the small vessels within deeper regions. Moreover, after 24 h of stroke progression, scattering signal enhancement was observed within the stroke region. We also evaluated the infarct extent and shape histologically. In summary, we present a novel approach for real-time mouse brain monitoring and ischemic variability analysis. This multimodal imaging method permits the analysis of thrombosis progression and reperfusion. Additionally and importantly, the system could be used to study the effect of poststroke drug treatments on blood flow in small arteries and capillaries of the brain.
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Affiliation(s)
- Hubert Dolezyczek
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Szymon Tamborski
- Nicolaus Copernicus University, Institute of Physics, Faculty of Physics, Astronomy and Informatics, Torun, Poland
| | - Piotr Majka
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Danuta Sampson
- University of Surrey, Surrey Biophotonics, Centre for Vision, Speech and Signal Processing, School of Biosciences and Medicine, Guildford, United Kingdom
| | - Maciej Wojtkowski
- Institute of Physical Chemistry of the Polish Academy of Sciences, Warsaw, Poland
| | - Grzegorz Wilczyński
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Maciej Szkulmowski
- Nicolaus Copernicus University, Institute of Physics, Faculty of Physics, Astronomy and Informatics, Torun, Poland
| | - Monika Malinowska
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
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