1
|
Song W, Zhuang Y, Yang Y, Xie D, Min C, Yuan X. Speckle Variance Photoacoustic Microscopy for Microhemodynamic Imaging. ACS Sens 2024. [PMID: 38625680 DOI: 10.1021/acssensors.4c00292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Relying on the strong optical absorption of hemoglobin to pulsed laser energy, photoacoustic microscopy provides morphological and functional information on microvasculature label-freely. Here, we propose speckle variance photoacoustic microscopy (SV-PAM), which harnesses intrinsic imaging contrast from temporal-varied photoacoustic signals of moving red blood cells in blood vessels, for recovering three-dimension hemodynamic images down to capillary-level resolution within the microcirculatory tissue beds in vivo. Calculating the speckle variance of consecutive photoacoustic B-scan frames acquired at the same lateral position enables accurate identification of blood perfusion and occlusion, which provides interpretations of dynamic blood flow in the microvasculature, in addition to the microvascular anatomic structures. We demonstrate high-resolution hemodynamic imaging of vascular occlusion and reperfusion in the microvasculature of mice ears in vivo. The results suggest that our SV-PAM is potentially invaluable for biomedical hemodynamic investigations, for example, imaging ischemic stroke and hemorrhagic stroke.
Collapse
Affiliation(s)
- Wei Song
- Nanophotonics Research Center, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China
| | - Yiyan Zhuang
- Nanophotonics Research Center, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China
| | - Yifan Yang
- Nanophotonics Research Center, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China
| | - Deyan Xie
- School of Science and Information Science, Qingdao Agricultural University, Qingdao 266109, China
| | - Changjun Min
- Nanophotonics Research Center, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China
| | - Xiaocong Yuan
- Nanophotonics Research Center, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China
- Research Center for Frontier Fundamental Studies, Zhejiang Laboratory, Hangzhou 311100, China
| |
Collapse
|
2
|
Qureshi MM, Allam N, Im J, Kwon HS, Chung E, Vitkin IA. Advances in laser speckle imaging: From qualitative to quantitative hemodynamic assessment. JOURNAL OF BIOPHOTONICS 2024; 17:e202300126. [PMID: 37545037 DOI: 10.1002/jbio.202300126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/03/2023] [Accepted: 07/27/2023] [Indexed: 08/08/2023]
Abstract
Laser speckle imaging (LSI) techniques have emerged as a promising method for visualizing functional blood vessels and tissue perfusion by analyzing the speckle patterns generated by coherent light interacting with living biological tissue. These patterns carry important biophysical tissue information including blood flow dynamics. The noninvasive, label-free, and wide-field attributes along with relatively simple instrumental schematics make it an appealing imaging modality in preclinical and clinical applications. The review outlines the fundamentals of speckle physics and the three categories of LSI techniques based on their degree of quantification: qualitative, semi-quantitative and quantitative. Qualitative LSI produces microvascular maps by capturing speckle contrast variations between blood vessels containing moving red blood cells and the surrounding static tissue. Semi-quantitative techniques provide a more accurate analysis of blood flow dynamics by accounting for the effect of static scattering on spatiotemporal parameters. Quantitative LSI such as optical speckle image velocimetry provides quantitative flow velocity measurements, which is inspired by the particle image velocimetry in fluid mechanics. Additionally, discussions regarding the prospects of future innovations in LSI techniques for optimizing the vascular flow quantification with associated clinical outlook are presented.
Collapse
Affiliation(s)
- Muhammad Mohsin Qureshi
- Division of Biophysics and Bioimaging, Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - Nader Allam
- Division of Biophysics and Bioimaging, Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Jeongmyo Im
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Hyuk-Sang Kwon
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Euiheon Chung
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
- AI Graduate School, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - I Alex Vitkin
- Division of Biophysics and Bioimaging, Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
- Department of Radiation Oncology, University of Toronto, Toronto, Canada
| |
Collapse
|
3
|
Lee M, Bang H, Lee E, Park S, Yoo H, Oh WY, Lee S. Imaging peritoneal blood vessels through optical coherence tomography angiography for laparoscopic surgery. JOURNAL OF BIOPHOTONICS 2024; 17:e202300221. [PMID: 37675626 DOI: 10.1002/jbio.202300221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 08/20/2023] [Accepted: 09/05/2023] [Indexed: 09/08/2023]
Abstract
Laparoscopic surgery presents challenges in identifying blood vessels due to lack of tactile feedback. The image-guided laparoscopic surgical tool (IGLaST) integrated with optical coherence tomography (OCT) has potential for in vivo blood vessel imaging; however, distinguishing vessels from surrounding tissue remains a challenge. In this study, we propose utilizing an inter-A-line intensity differentiation-based OCT angiography (OCTA) to improve visualization of blood vessels. By evaluating a tissue phantom with varying flow speeds, we optimized the system's blood flow imaging capabilities in terms of minimum detectable flow and contrast-to-noise ratio. In vivo experiments on rat and porcine models, successfully visualized previously unidentified blood vessels and concealed blood flows beneath the 1 mm depth peritoneum. Qualitative comparison of various OCTA algorithms indicated that the intensity differentiation-based algorithm performed best for our application. We believe that implementing IGLaST with OCTA can enhance surgical outcomes and reduce procedure time in laparoscopic surgeries.
Collapse
Affiliation(s)
- Minsuk Lee
- Medical Device Development Center, Osong Medical Innovation Foundation, Cheongju, Chungbuk, Korea
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - Hyeonjin Bang
- Medical Device Development Center, Osong Medical Innovation Foundation, Cheongju, Chungbuk, Korea
| | - Eungjang Lee
- Medical Device Development Center, Osong Medical Innovation Foundation, Cheongju, Chungbuk, Korea
| | - Sungsoo Park
- Division of Foregut Surgery, Anam Hospital, Korea University College of Medicine, Seoul, Korea
- Department of Surgery, Anam Hospital, Korea University College of Medicine, Seoul, Korea
| | - Hongki Yoo
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - Wang-Yuhl Oh
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - Seungrag Lee
- Medical Device Development Center, Osong Medical Innovation Foundation, Cheongju, Chungbuk, Korea
| |
Collapse
|
4
|
Burri C, Salzmann S, Wandel J, Hoffmann L, Považay B, Meier C, Frenz M. Real-time OCT feedback-controlled RPE photodisruption in ex vivo porcine eyes using 8 microsecond laser pulses. BIOMEDICAL OPTICS EXPRESS 2023; 14:6328-6349. [PMID: 38420306 PMCID: PMC10898567 DOI: 10.1364/boe.503941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/24/2023] [Accepted: 11/12/2023] [Indexed: 03/02/2024]
Abstract
Selective retinal pigment epithelium (RPE) photodisruption requires reliable real-time feedback dosimetry (RFD) to prevent unwanted overexposure. In this study, optical coherence tomography (OCT) based RFD was investigated in ex vivo porcine eyes exposed to laser pulses of 8 µs duration (wavelength: 532 nm, exposure area: 90 × 90 µm2, radiant exposure: 247 to 1975 mJ/µm2). For RFD, fringe washouts in time-resolved OCT M-scans (central wavelength: 870 nm, scan rate: 85 kHz) were compared to an RPE cell viability assay. Statistical analysis revealed a moderate correlation between RPE lesion size and applied treatment energy, suggesting RFD adaptation to inter- and intraindividual RPE pigmentation and ocular transmission.
Collapse
Affiliation(s)
- Christian Burri
- optoLab, Institute for Human Centered Engineering, Bern University of Applied Sciences, Biel, Switzerland
- Biomedical Photonics Group, Institute of Applied Physics, University of Bern, Bern, Switzerland
| | - Simon Salzmann
- optoLab, Institute for Human Centered Engineering, Bern University of Applied Sciences, Biel, Switzerland
| | - Jasmin Wandel
- Institute for Optimisation and Data Analysis, Bern University of Applied Sciences, Burgdorf, Switzerland
| | - Leonie Hoffmann
- optoLab, Institute for Human Centered Engineering, Bern University of Applied Sciences, Biel, Switzerland
| | - Boris Považay
- optoLab, Institute for Human Centered Engineering, Bern University of Applied Sciences, Biel, Switzerland
| | - Christoph Meier
- optoLab, Institute for Human Centered Engineering, Bern University of Applied Sciences, Biel, Switzerland
| | - Martin Frenz
- Biomedical Photonics Group, Institute of Applied Physics, University of Bern, Bern, Switzerland
| |
Collapse
|
5
|
Simoncic U, Milanic M. Tail Artifact Removal via Transmittance Effect Subtraction in Optical Coherence Tail Artifact Images. SENSORS (BASEL, SWITZERLAND) 2023; 23:9312. [PMID: 38067685 PMCID: PMC10708777 DOI: 10.3390/s23239312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 11/14/2023] [Accepted: 11/20/2023] [Indexed: 12/18/2023]
Abstract
Optical Coherence Tomography Angiography (OCTA) has revolutionized non-invasive, high-resolution imaging of blood vessels. However, the challenge of tail artifacts in OCTA images persists. In response, we present the Tail Artifact Removal via Transmittance Effect Subtraction (TAR-TES) algorithm that effectively mitigates these artifacts. Through a simple physics-based model, the TAR-TES accounts for variations in transmittance within the shallow layers with the vasculature, resulting in the removal of tail artifacts in deeper layers after the vessel. Comparative evaluations with alternative correction methods demonstrate that TAR-TES excels in eliminating these artifacts while preserving the essential integrity of vasculature images. Crucially, the success of the TAR-TES is closely linked to the precise adjustment of a weight constant, underlining the significance of individual dataset parameter optimization. In conclusion, TAR-TES emerges as a powerful tool for enhancing OCTA image quality and reliability in both clinical and research settings, promising to reshape the way we visualize and analyze intricate vascular networks within biological tissues. Further validation across diverse datasets is essential to unlock the full potential of this physics-based solution.
Collapse
Affiliation(s)
- Urban Simoncic
- Faculty of Mathematics and Physics, University of Ljubljana, 1000 Ljubljana, Slovenia;
- Jozef Stefan Institute, 1000 Ljubljana, Slovenia
| | - Matija Milanic
- Faculty of Mathematics and Physics, University of Ljubljana, 1000 Ljubljana, Slovenia;
- Jozef Stefan Institute, 1000 Ljubljana, Slovenia
| |
Collapse
|
6
|
Hou H, Tang Y, Coole JB, Kortum A, Schwarz RA, Carns J, Gillenwater AM, Ramalingam P, Milbourne A, Salcedo MP, Schmeler KM, Richards-Kortum RR. Scanning darkfield high-resolution microendoscope for label-free microvascular imaging. BIOMEDICAL OPTICS EXPRESS 2023; 14:5097-5112. [PMID: 37854554 PMCID: PMC10581811 DOI: 10.1364/boe.498584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/31/2023] [Accepted: 09/01/2023] [Indexed: 10/20/2023]
Abstract
Characterization of microvascular changes during neoplastic progression has the potential to assist in discriminating precancer and early cancer from benign lesions. Here, we introduce a novel high-resolution microendoscope that leverages scanning darkfield reflectance imaging to characterize angiogenesis without exogenous contrast agents. Scanning darkfield imaging is achieved by coupling programmable illumination with a complementary metal-oxide semiconductor (CMOS) camera rolling shutter, eliminating the need for complex optomechanical components and making the system portable, low-cost (<$5,500) and simple to use. Imaging depth is extended by placing a gradient-index (GRIN) lens at the distal end of the imaging fiber to resolve subepithelial microvasculature. We validated the capability of the scanning darkfield microendoscope to visualize microvasculature at different anatomic sites in vivo by imaging the oral cavity of healthy volunteers. Images of cervical specimens resected for suspected neoplasia reveal distinct microvascular patterns in columnar and squamous epithelium with different grades of precancer, indicating the potential of scanning darkfield microendoscopy to aid in efforts to prevent cervical cancer through early diagnosis.
Collapse
Affiliation(s)
- Huayu Hou
- Department of Bioengineering, Rice University, Houston, TX 77005, USA
| | - Yubo Tang
- Department of Bioengineering, Rice University, Houston, TX 77005, USA
| | - Jackson B. Coole
- Department of Bioengineering, Rice University, Houston, TX 77005, USA
| | - Alex Kortum
- Department of Bioengineering, Rice University, Houston, TX 77005, USA
| | | | - Jennifer Carns
- Department of Bioengineering, Rice University, Houston, TX 77005, USA
| | - Ann M. Gillenwater
- Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Preetha Ramalingam
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Andrea Milbourne
- Department of Gynecologic Oncology and Reproductive Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Mila P. Salcedo
- Department of Gynecologic Oncology and Reproductive Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Department of Obstetrics and Gynecology, Federal University of Health Sciences of Porto Alegre (UFCSPA)/Santa Casa Hospital of Porto Alegre, Porto Alegre, Brazil
| | - Kathleen M. Schmeler
- Department of Gynecologic Oncology and Reproductive Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | | |
Collapse
|
7
|
Choi H, Iyer RR, Renteria CA, Boppart SA. Phase-sensitive detection of anomalous diffusion dynamics in the neuronal membrane induced by ion channel gating. Phys Med Biol 2023; 68:065005. [PMID: 36848681 PMCID: PMC10010434 DOI: 10.1088/1361-6560/acbf9c] [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: 07/28/2022] [Revised: 02/14/2023] [Accepted: 02/27/2023] [Indexed: 03/01/2023]
Abstract
Non-ergodicity of neuronal dynamics from rapid ion channel gating through the membrane induces membrane displacement statistics that deviate from Brownian motion. The membrane dynamics from ion channel gating were imaged by phase-sensitive optical coherence microscopy. The distribution of optical displacements of the neuronal membrane showed a Lévy-like distribution and the memory effect of the membrane dynamics by the ionic gating was estimated. The alternation of the correlation time was observed when neurons were exposed to channel-blocking molecules. Non-invasive optophysiology by detecting the anomalous diffusion characteristics of dynamic images is demonstrated.
Collapse
Affiliation(s)
- Honggu Choi
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States of America
| | - Rishyashring R Iyer
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States of America
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, United States of America
| | - Carlos A Renteria
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States of America
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, United States of America
| | - Stephen A Boppart
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States of America
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, United States of America
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, United States of America
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, United States of America
- Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, United States of America
| |
Collapse
|
8
|
Lin L, Zhang X, Huang C, Zhang Z. Evaluation of retinal vascular density and related factors using OCTA in children and adolescents with myopia without maculopathy. J Int Med Res 2023; 51:3000605221150136. [PMID: 36694304 PMCID: PMC9893076 DOI: 10.1177/03000605221150136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Myopia is the most common ophthalmic condition worldwide with a rapidly increasing prevalence. This study aimed to compare the retinal microvasculature in the superficial capillary plexus (SCP) in children and adolescents with mild and moderate/high myopia using optical coherence tomography angiography, determine the relationship between retinal parameters and axial length (AL), and understand the occurrence and progression of myopia in microcirculation. METHODS This prospective observational study included 39 participants with mild myopia and 33 participants with moderate/high myopia. Vessel density (VD) and perfusion density (PD) in the SCP, the foveal avascular zone (FAZ), and AL were compared between the groups and the relationship between these retinal parameters and AL was assessed. RESULTS No difference in SCP VD or PD was observed between the two groups. The FAZ did not differ significantly between groups whereas significant differences in age, height, refractive status, and AL were observed. Significantly shorter AL was observed in participants with mild myopia compared with the moderate/high myopia group. Age was positively correlated with height (r = 0.852) and refractive status was negatively correlated with AL (r = -0.588). AL was positively correlated with VD (r = 0.317) and PD (r = 0.308) in the SCP and AL was negatively correlated with the FAZ (r = -0.434). CONCLUSIONS This study revealed that superficial foveal microvessel density was unaffected in children and adolescents without pathological myopia. However, myopia progression was associated with a change in AL, and an AL increase altered macular blood flow.
Collapse
Affiliation(s)
| | | | | | - Zhaode Zhang
- Zhaode Zhang, Ningde City Hospital affiliated with Fujian Medical University, No.13 Mindong East Road, Fujian, Ningde 352100, China.
| |
Collapse
|
9
|
Zhang W, He B, Wu Y, Tao Y, Zhu F, Cai W, Liu N, Zhao Q, Xue P. Tail artifacts removal of three-dimensional optical coherence tomography angiography with common parts extraction method. JOURNAL OF BIOPHOTONICS 2022; 15:e202200155. [PMID: 36328058 DOI: 10.1002/jbio.202200155] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/11/2022] [Accepted: 08/02/2022] [Indexed: 06/16/2023]
Abstract
In optical coherence tomography angiography (OCTA), each blood vessel has a tail artifact. These tails of superficial vessels will shadow underlying the deep vascular images and make it difficult to reconstruct the three-dimensional (3D) image of the vessels. As 3D structure can provide much more information than two-dimensional (2D) images, it is important to develop a method to remove the artifacts. In this letter, we introduce an image processing technique based on common parts extraction to remove the artifacts. With the help of subtraction operation and erode operation, our method can reconstruct the 3D image of vascular network by extracting the common parts of adjacent B-Scan OCTA images. Vessels of palm are used as samples to experimentally demonstrate our technique. In the 3D image, we can see the interesting phenomenon that the ends of the blood vessels which close to the surface of the skin point toward the surface.
Collapse
Affiliation(s)
- Wenxin Zhang
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing, China
- State Key Laboratory of Low-dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
| | - Bin He
- State Key Laboratory of Low-dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
| | - Yangkang Wu
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Yuxiu Tao
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Fu Zhu
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Wenchao Cai
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Ning Liu
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Qiang Zhao
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Ping Xue
- State Key Laboratory of Low-dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
| |
Collapse
|
10
|
Wei X, Hormel TT, Pi S, Wang B, Morrison JC, Jia Y. Wide-field sensorless adaptive optics swept-source optical coherence tomographic angiography in rodents. OPTICS LETTERS 2022; 47:5060-5063. [PMID: 36181186 DOI: 10.1364/ol.472387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 09/04/2022] [Indexed: 06/16/2023]
Abstract
In this study, we present a sensorless adaptive optics swept-source optical coherence tomographic angiography (sAO-SS-OCTA) imaging system for mice. Real-time graphics processing unit (GPU)-based OCTA image acquisition and processing software were applied to guide wavefront correction using a deformable mirror based on signal strength index (SSI) from both OCT and OCTA images. High-resolution OCTA images with aberrations corrected and contrast enhanced were successfully acquired. Fifty-degree field of view high-resolution montaged OCTA images were also acquired.
Collapse
|
11
|
Akdogan M, Dogan M, Beysel S, Gobeka HH, Sabaner MC, Oran M. Optical coherence tomography angiography characteristics of the retinal and optic disc morphology in prolactinoma. Microvasc Res 2022; 144:104424. [PMID: 36007656 DOI: 10.1016/j.mvr.2022.104424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 07/01/2022] [Accepted: 08/19/2022] [Indexed: 10/31/2022]
Abstract
PURPOSE To investigate changes in the retinal and optic disc (OD) morphology in prolactinoma patients without optical chiasmal compression and/or visual field defects using optical coherence tomography angiography (OCTA). METHODS In this cross-sectional imaging study, 16 consecutive prolactinoma patients (group 1, 32 eyes) and 15 age- and gender-matched healthy subjects (group 2, 30 eyes) underwent a thorough neuro-ophthalmological examination, which included testing for the presence of any intracranial compressive lesion that could cause optic neuropathy. Retinal morphological parameters, outer retinal and choriocapillaris flow areas, as well as OD vessel density (VD) and retinal nerve fiber layer (RNFL) thickness in for quadrants were then measured using OCTA. RESULTS Mean age (p = 0.537) and gender (p = 0.385) of participants in groups 1 and 2 did not differ significantly. The mean BCVA for both groups was 0.00 ± 0.00 logMAR. Microadenomas made up the majority of prolactinomas (87.1 %). All retinal morphological parameters in deep capillary plexus (excluding foveal VD) differed significantly between groups 1 and 2 (whole: p < 0.001, parafoveal: p = 0.021, and perifoveal: p < 0.001). Peripapillary RNFL thickness in temporal (p < 0.001), nasal (p = 0.010), and inferior (p = 0.007) quadrants also differed significantly between the two groups. Foveal deep (r = -0.304, p = 0.035) and choriocapillaris flow (r = -0.511, p = 0.008) were negatively correlated with tumor size at diagnosis. CONCLUSIONS Significant microvascular morphological changes, particularly in the deep retinal layer, as well as in the peripapillary RNFL thickness, were observed in prolactinoma patients. OCTA appears to be capable of detecting non-manifest circumpapillary and even intra-retinal microvascular changes even when there are no obvious signs of prolactinoma-related ocular complications caused by chiasmal compression.
Collapse
Affiliation(s)
- Mubera Akdogan
- Afyonkarahisar Health Sciences University, Faculty of Medicine, Department of Ophthalmology, Afyonkarahisar, Turkey
| | - Mustafa Dogan
- Afyonkarahisar Health Sciences University, Faculty of Medicine, Department of Ophthalmology, Afyonkarahisar, Turkey
| | - Selvihan Beysel
- Afyonkarahisar Health Sciences University, Faculty of Medicine, Department of Endocrinology and Metabolism, Afyonkarahisar, Turkey
| | - Hamidu Hamisi Gobeka
- Afyonkarahisar Health Sciences University, Faculty of Medicine, Department of Ophthalmology, Afyonkarahisar, Turkey.
| | - Mehmet Cem Sabaner
- Afyonkarahisar Health Sciences University, Faculty of Medicine, Department of Ophthalmology, Afyonkarahisar, Turkey
| | - Merve Oran
- Afyonkarahisar Health Sciences University, Faculty of Medicine, Department of Ophthalmology, Afyonkarahisar, Turkey
| |
Collapse
|
12
|
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.
Collapse
|
13
|
Maguluri G, Grimble J, Mujat M, Park J, Caron A, Iftimia N. Fiber‐based hand‐held
RCM‐OCT
probe for noninvasive assessment of skin lesions and therapy guidance. TRANSLATIONAL BIOPHOTONICS 2022; 4. [PMID: 36176918 PMCID: PMC9514145 DOI: 10.1002/tbio.202200002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Noninvasive assessment of skin lesions, especially of basal cell carcinoma (BCC), has benefited more recently from the use of optical imaging techniques such as optical coherence tomography (OCT) and reflectance confocal microscopy (RCM). While RCM provides submicron scale resolution and thus enables identification of skin morphological changes of the skin, with the downside of limited penetration depth, OCT imaging of the same lesion brings the benefit of better resolving its depth of invasion. OCT and RCM can be used either individually or combined within the same instrument for the noninvasive diagnosis of nonmelanoma skin cancers (NMSCs). Their combined use has shown to provide certain benefits such as better characterization of the lesion's margins, both in depth and laterally, as well as improved sensitivity and specificity, as previously demonstrated by our team. In this paper we report a new "fiber-based" implementation of the second-generation RCM-OCT hand-held probe. The fiber-based implementation of both imaging modalities enabled the construction of a smaller footprint/lower weight hand-held probe. Its preliminary evaluation on the skin of healthy volunteers is reported here, demonstrating improved capabilities for resolving sub-cellular structures and image skin morphology with micron-scale resolution to a higher depth than in the previous implementation, while also enabling the construction of angiography maps showing vascular remodeling.
Collapse
|
14
|
Luisi JD, Lin JL, Ameredes BT, Motamedi M. Spatial-Temporal Speckle Variance in the En-Face View as a Contrast for Optical Coherence Tomography Angiography (OCTA). SENSORS (BASEL, SWITZERLAND) 2022; 22:s22072447. [PMID: 35408061 PMCID: PMC9003003 DOI: 10.3390/s22072447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/19/2022] [Accepted: 03/20/2022] [Indexed: 05/09/2023]
Abstract
Optical Coherence Tomography (OCT) is an adaptable depth-resolved imaging modality capable of creating a non-invasive 'digital biopsy' of the eye. One of the latest advances in OCT is optical coherence tomography angiography (OCTA), which uses the speckle variance or phase change in the signal to differentiate static tissue from blood flow. Unlike fluorescein angiography (FA), OCTA is contrast free and depth resolved. By combining high-density scan patterns and image processing algorithms, both morphometric and functional data can be extracted into a depth-resolved vascular map of the retina. The algorithm that we explored takes advantage of the temporal-spatial relationship of the speckle variance to improve the contrast of the vessels in the en-face OCT with a single frame. It also does not require the computationally inefficient decorrelation of multiple A-scans to detect vasculature, as used in conventional OCTA analysis. Furthermore, the spatial temporal OCTA (ST-OCTA) methodology tested offers the potential for post hoc analysis to improve the depth-resolved contrast of specific ocular structures, such as blood vessels, with the capability of using only a single frame for efficient screening of large sample volumes, and additional enhancement by processing with choice of frame averaging methods. Applications of this method in pre-clinical studies suggest that the OCTA algorithm and spatial temporal methodology reported here can be employed to investigate microvascularization and blood flow in the retina, and possibly other compartments of the eye.
Collapse
Affiliation(s)
- Jonathan D. Luisi
- Department of Internal Medicine, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX 77555, USA; (J.D.L.); (B.T.A.)
| | - Jonathan L. Lin
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX 77555, USA;
| | - Bill T. Ameredes
- Department of Internal Medicine, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX 77555, USA; (J.D.L.); (B.T.A.)
- Department of Pharmacology and Toxicology, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX 77555, USA
| | - Massoud Motamedi
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX 77555, USA;
- Correspondence:
| |
Collapse
|
15
|
Evaluation of Mannitol Intervention Effects on Ischemic Cerebral Edema in Mice Using Swept Source Optical Coherence Tomography. PHOTONICS 2022. [DOI: 10.3390/photonics9020081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cerebral edema is a serious complication of ischemic cerebrovascular disease and mannitol is a commonly used dehydrating agent for relieving cerebral edema. However, the edema state and surrounding vascular perfusion level during mannitol treatment remains unclear, which affects the clinical application of the medicine. In this paper, we demonstrated the role of swept-source optical coherence tomography (OCT) in the evaluation of mannitol efficacy using mouse models. The OCT-based angiography and attenuation imaging technology were used to obtain the cerebral vascular perfusion level and cerebral edema state at different times. Vascular parameters and edema parameters were quantified and compared. Experimental results show that mannitol can significantly reduce the water content in the central region of edema, effectively inhibiting the rapid growth of the edema area, and restoring cerebral blood flow. On average, the edema area decreased by 33% after 2 h, and the vascular perfusion density increased by 12% after 5 h. This work helps to provide a valuable theoretical basis and research ideas for the clinical treatment of cerebral edema.
Collapse
|
16
|
Wang JV, Mehrabi JN, Abrouk M, Pomerantz H, Palma AM, Zachary CB, Waibel JS, Kelly KM, Geronemus RG. Analysis of port-wine birthmark vascular characteristics by location: Utility of optical coherence tomography mapping. Lasers Surg Med 2021; 54:98-104. [PMID: 34888897 DOI: 10.1002/lsm.23496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 11/10/2021] [Accepted: 11/10/2021] [Indexed: 11/08/2022]
Abstract
INTRODUCTION Port-wine birthmarks (PWBs) are congenital capillary malformations that can be located on any area of the body. Vascular features include vessel size, depth, and density, which can greatly differ between patients, individual lesions, and even sites within the same lesion. Previous studies have determined that the location of PWB lesions has impacted their clinical response to laser treatment. OBJECTIVE We utilized dynamic optical coherence tomography (D-OCT) to measure in vivo vessel diameter, density, and superficial plexus depth in patients of all ages with PWB on various sites of the body. We hypothesized that these vascular characteristics would differ according to body location. MATERIALS AND METHODS Patients who had a PWB and presented to clinic at three sites for treatment with the pulsed dye laser (PDL) were enrolled into the study. A D-OCT scanner was utilized for noninvasive, in vivo imaging of PWB lesions. The depth of the top portion of the superficial vascular plexus was estimated as the depth at which the vessel density reaches 50% of the maximum. Vessel diameter and density were calculated by incorporated software algorithm. RESULTS A total of 108 patients were enrolled into the study. There was a total of 204 measurements of PWB lesions. Of all patients, 56.5% (n = 61) reported having a previous treatment with PDL. Of all D-OCT scans, 62.3% (n = 127) were located on the head, 14.2% (n = 29) the upper extremities, 8.3% (n = 17) the lower extremities, 7.8% (n = 16) the trunk, and 7.8% (n = 15) the neck. All locations were compared for each vascular characteristic. For superficial plexus depth, lesions on the head were significantly shallower than those on the upper extremities (217 vs. 284 µm; p < 0.001) and lower extremities (217 vs. 309 µm; p < 0.001). For vessel diameter, lesions on the head had significantly larger vessels than those on the upper extremities (100 vs. 72 µm; p = 0.001). For vessel density, lesions on the head had significantly denser vessels than those on the trunk (19% vs. 9.6%; p = 0.039) and upper extremities (19% vs. 9.3%; p < 0.001) CONCLUSIONS: PWB lesions have distinct vascular characteristics, which can be associated with their body location. This includes superficial vascular plexus depth as well as vessel diameter and density.
Collapse
Affiliation(s)
- Jordan V Wang
- Laser & Skin Surgery Center of New York, New York, New York, USA
| | - Joseph N Mehrabi
- Department of Dermatology, University of California, Irvine, California, USA
| | - Michael Abrouk
- Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Hyemin Pomerantz
- Laser & Skin Surgery Center of New York, New York, New York, USA
| | - Anton M Palma
- Institute for Clinical and Translational Science, University of California, Irvine, California, USA
| | | | - Jill S Waibel
- Miami Dermatology and Laser Institute, Miami, Florida, USA
| | - Kristen M Kelly
- Department of Dermatology, University of California, Irvine, California, USA.,Beckman Laser Institute and Medical Clinic, University of California, Irvine, California, USA
| | - Roy G Geronemus
- Laser & Skin Surgery Center of New York, New York, New York, USA
| |
Collapse
|
17
|
Vascular characteristics of port wine birthmarks as measured by dynamic optical coherence tomography. J Am Acad Dermatol 2021; 85:1537-1543. [PMID: 34390783 DOI: 10.1016/j.jaad.2021.08.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 08/01/2021] [Accepted: 08/03/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND Port wine birthmarks (PWBs) are congenital capillary malformations. Vessel characteristics, such as diameter and depth, may impact presentation and outcomes. They can be imaged using dynamic optical coherence tomography, a high-resolution, noninvasive imaging method. PURPOSE We conducted a cross-sectional observational study to measure in vivo vascular characteristics as a function of PWB color. METHODS Patients undergoing treatment for PWB were recruited from 3 sites. PWBs were classified by color. Dynamic optical coherence tomography images with calculations were obtained. RESULTS One hundred eight patients were enrolled. Mean age correlated with PWB color, with birthmarks being lighter in younger patients and darker in older patients (P < .01). Mean superficial plexus depth was significantly shallower in purple PWBs than in pink PWBs. Color was not associated with significant differences in mean superficial vessel density or diameter. Among pink PWBs, each 10-year increase in age was associated with a 10.6-μm increase in superficial plexus depth. Among purple PWBs, each 10-year increase in age was associated with a 16.2-μm reduction in superficial plexus depth. In lesions without prior treatment, vessel density was 12.7% lower in purple PWBs than in pink PWBs. CONCLUSION Superficial vessels of purple PWBs were significantly closer to the epidermis than those of pink PWBs, which might impact optimal laser parameters.
Collapse
|
18
|
Jang JH, Solarana K, Hammer DX, Fisher JAN. Dissecting the microvascular contributions to diffuse correlation spectroscopy measurements of cerebral hemodynamics using optical coherence tomography angiography. NEUROPHOTONICS 2021; 8:025006. [PMID: 33912621 PMCID: PMC8071783 DOI: 10.1117/1.nph.8.2.025006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
Significance: Diffuse correlation spectroscopy (DCS) is an emerging noninvasive, diffuse optical modality that purportedly enables direct measurements of microvasculature blood flow. Functional optical coherence tomography angiography (OCT-A) can resolve blood flow in vessels as fine as capillaries and thus has the capability to validate key attributes of the DCS signal. Aim: To characterize activity in cortical vasculature within the spatial volume that is probed by DCS and to identify populations of blood vessels that are most representative of the DCS signals. Approach: We performed simultaneous measurements of somatosensory-evoked cerebral blood flow in mice in vivo using both DCS and OCT-A. Results: We resolved sensory-evoked blood flow in the somatosensory cortex with both modalities. Vessels with diameters smaller than 10 μ m featured higher peak flow rates during the initial poststimulus positive increase in flow, whereas larger vessels exhibited considerably larger magnitude of the subsequent undershoot. The simultaneously recorded DCS waveforms correlated most highly with flow in the smallest vessels, yet featured a more prominent undershoot. Conclusions: Our direct, multiscale, multimodal cross-validation measurements of functional blood flow support the assertion that the DCS signal preferentially represents flow in microvasculature. The significantly greater undershoot in DCS, however, suggests a more spatially complex relationship to flow in cortical vasculature during functional activation.
Collapse
Affiliation(s)
- James H. Jang
- Center for Devices and Radiological Health, U. S. Food and Drug Administration, Silver Spring, Maryland, United States
| | - Krystyna Solarana
- Center for Devices and Radiological Health, U. S. Food and Drug Administration, Silver Spring, Maryland, United States
| | - Daniel X. Hammer
- Center for Devices and Radiological Health, U. S. Food and Drug Administration, Silver Spring, Maryland, United States
| | - Jonathan A. N. Fisher
- New York Medical College, Department of Physiology, Valhalla, New York, United States
| |
Collapse
|
19
|
Wu S, Okada R, Liu Y, Fang Y, Yan F, Wang C, Li H, Kobayashi H, Chen Y, Tang Q. Quantitative analysis of vascular changes during photoimmunotherapy using speckle variance optical coherence tomography (SV-OCT). BIOMEDICAL OPTICS EXPRESS 2021; 12:1804-1820. [PMID: 33996199 PMCID: PMC8086455 DOI: 10.1364/boe.419163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/24/2021] [Accepted: 02/24/2021] [Indexed: 06/12/2023]
Abstract
Near-infrared (NIR) photoimmunotherapy (NIR-PIT) is an emerging cancer therapy based on a monoclonal antibody and phthalocyanine dye conjugate. Direct tumor necrosis and immunogenic cell death occur during NIR irradiation. However, the alteration of tumor blood vessels and blood volume inside the blood vessels induced by the NIR-PIT process is still unknown. In our study, a speckle variance (SV) algorithm combined with optical coherence tomography (OCT) technology was applied to monitor the change of blood vessels and the alterations of the blood volume inside the blood vessels during and after NIR-PIT treatment. Vascular density and the measurable diameter of the lumen in the blood vessel (the diameter of the region filled with blood) were extracted for quantitively uncovering the alterations of blood vessels and blood volume induced by NIR-PIT treatment. The results indicate that both the density and the diameter of the lumen in the blood vessels decrease during the NIR-PIT process, while histological results indicated the blood vessels were dilated. The increase of permeability of blood vessels could lead to the increase of the blood pool volume within the tumor (shown in histology) and results in the decrease of free-moving red blood cells inside the blood vessels (shown in SV-OCT).
Collapse
Affiliation(s)
- Shulian Wu
- College of Photonic and Electronic Engineering, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, Fujian Provincial Key Laboratory of Photonic Technology, Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education, Fujian Normal University, Fuzhou, 350007, China
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
- These authors contributed equally to this work
| | - Ryuhei Okada
- National Institute of Health, National Cancer Institute, Molecular Imaging Program, Bldg 10, Room B3B47, Bethesda, Maryland 20892-1088, USA
- These authors contributed equally to this work
| | - Yi Liu
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Yuhong Fang
- College of Photonic and Electronic Engineering, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, Fujian Provincial Key Laboratory of Photonic Technology, Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education, Fujian Normal University, Fuzhou, 350007, China
| | - Feng Yan
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK 73019, USA
| | - Chen Wang
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK 73019, USA
| | - Hui Li
- College of Photonic and Electronic Engineering, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, Fujian Provincial Key Laboratory of Photonic Technology, Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education, Fujian Normal University, Fuzhou, 350007, China
| | - Hisataka Kobayashi
- National Institute of Health, National Cancer Institute, Molecular Imaging Program, Bldg 10, Room B3B47, Bethesda, Maryland 20892-1088, USA
| | - Yu Chen
- College of Photonic and Electronic Engineering, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, Fujian Provincial Key Laboratory of Photonic Technology, Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education, Fujian Normal University, Fuzhou, 350007, China
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
- Department of Biomedical Engineering, University of Massachusetts, Amherst, MA 01003, USA
| | - Qinggong Tang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK 73019, USA
| |
Collapse
|
20
|
Kanngiesser J, Roth B. Wavefront Shaping Concepts for Application in Optical Coherence Tomography-A Review. SENSORS (BASEL, SWITZERLAND) 2020; 20:E7044. [PMID: 33316998 PMCID: PMC7763956 DOI: 10.3390/s20247044] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/02/2020] [Accepted: 12/07/2020] [Indexed: 01/10/2023]
Abstract
Optical coherence tomography (OCT) enables three-dimensional imaging with resolution on the micrometer scale. The technique relies on the time-of-flight gated detection of light scattered from a sample and has received enormous interest in applications as versatile as non-destructive testing, metrology and non-invasive medical diagnostics. However, in strongly scattering media such as biological tissue, the penetration depth and imaging resolution are limited. Combining OCT imaging with wavefront shaping approaches significantly leverages the capabilities of the technique by controlling the scattered light field through manipulation of the field incident on the sample. This article reviews the main concepts developed so far in the field and discusses the latest results achieved with a focus on signal enhancement and imaging.
Collapse
Affiliation(s)
- Jonas Kanngiesser
- Hannoversches Zentrum für Optische Technologien, Leibniz Universität Hannover, Nienburger Straße 17, D-30167 Hannover, Germany;
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering–Innovation Across Disciplines), D-30167 Hannover, Germany
| | - Bernhard Roth
- Hannoversches Zentrum für Optische Technologien, Leibniz Universität Hannover, Nienburger Straße 17, D-30167 Hannover, Germany;
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering–Innovation Across Disciplines), D-30167 Hannover, Germany
| |
Collapse
|
21
|
Intact in vivo visualization of telencephalic microvasculature in medaka using optical coherence tomography. Sci Rep 2020; 10:19831. [PMID: 33199719 PMCID: PMC7669881 DOI: 10.1038/s41598-020-76468-6] [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: 04/02/2020] [Accepted: 10/28/2020] [Indexed: 11/09/2022] Open
Abstract
To date, various human disease models in small fish-such as medaka (Oryzias lapties)-have been developed for medical and pharmacological studies. Although genetic and environmental homogeneities exist, disease progressions can show large individual differences in animal models. In this study, we established an intact in vivo angiographic approach and explored vascular networks in the telencephalon of wild-type adult medaka using the spectral-domain optical coherence tomography. Our approach, which required neither surgical operations nor labeling agents, allowed to visualize blood vessels in medaka telencephala as small as about 8 µm, that is, almost the size of the blood cells of medaka. Besides, we could show the three-dimensional microvascular distribution in the medaka telencephalon. Therefore, the intact in vivo imaging via optical coherence tomography can be used to perform follow-up studies on cerebrovascular alterations in metabolic syndrome and their associations with neurodegenerative disease models in medaka.
Collapse
|
22
|
Raghunathan R, Liu CH, Kouka A, Singh M, Miranda RC, Larin KV. Dose-response analysis of microvasculature changes in the murine fetal brain and the maternal extremities due to prenatal ethanol exposure. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:JBO-200176RR. [PMID: 33244919 PMCID: PMC7689263 DOI: 10.1117/1.jbo.25.12.126001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 11/06/2020] [Indexed: 05/29/2023]
Abstract
SIGNIFICANCE Prenatal exposure to ethanol causes several morphological and neurobehavioral deficits. While there are some studies on the effects of ethanol exposure on blood flow, research focusing on acute changes in the microvasculature is limited. AIM The first aim of this study was to assess the dose-dependent changes in murine fetal brain microvasculature of developing fetuses in response to maternal alcohol consumption. The second aim was to quantify changes in vasculature occurring concurrently in the mother's hindlimb and the fetus's brain after maternal exposure to alcohol. APPROACH Correlation mapping optical coherence angiography was used to evaluate the effects of prenatal exposure to different doses of ethanol (3, 1.5, and 0.75 g / kg) on murine fetal brain vasculature in utero. Additionally, simultaneous imaging of maternal peripheral vessels and the fetal brain vasculature was performed to assess changes of the vasculature occurring concurrently in response to ethanol consumption. RESULTS The fetal brain vessel diameters (VDs) decreased by ∼47 % , 30%, and 14% in response to ethanol doses of 3, 1.5, and 0.75 g / kg, respectively. However, the mother's hindlimb VD increased by 63% in response to ethanol at a dose of 3 g / kg. CONCLUSIONS Results showed a dose-dependent reduction in vascular blood flow in fetal brain vessels when the mother was exposed to ethanol, whereas vessels in the maternal hindlimb exhibited concurrent vasodilation.
Collapse
Affiliation(s)
- Raksha Raghunathan
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Chih-Hao Liu
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Amur Kouka
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Manmohan Singh
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Rajesh C. Miranda
- Texas A&M University Health Science Center College of Medicine, Department of Neuroscience and Experimental Therapeutics, Bryan, Texas, United States
| | - Kirill V. Larin
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| |
Collapse
|
23
|
Yamazaki K, Li E, Miyazawa A, Kobayashi M, Sayo T, Makita S, Takahashi Y, Yasuno Y, Sakai S. Depth-resolved investigation of multiple optical properties and wrinkle morphology in eye-corner areas with multi-contrast Jones matrix optical coherence tomography. Skin Res Technol 2020; 27:435-443. [PMID: 33111404 DOI: 10.1111/srt.12960] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 09/07/2020] [Indexed: 11/27/2022]
Abstract
BACKGROUND Multi-contrast Jones matrix optical coherence tomography (JM-OCT) can provide quantitative depth-resolved local optical properties by improving the measurement algorithm. MATERIALS AND METHODS We examined the relationship between depth-resolved local optical properties of eye-corner skin measured by JM-OCT and corresponding wrinkle morphology of aged women (n = 21; age range, 71.7 ± 1.7 years). Wrinkle morphology was analyzed by measuring the surface topography of three-dimensional replicas. The same regions were measured three-dimensionally by JM-OCT, and the local optical properties at each depth were computed. RESULTS Birefringence (BR) and mean wrinkle depth correlated significantly at a depth of 88.2-138.6 µm from the skin surface, and attenuation coefficient (AC) and mean wrinkle depth correlated significantly at a depth of 12.6-18.9 µm and 189-459.9 μm from the skin surface, although a degree of polarization uniformity (DOPU) did not. Stepwise multiple regression analysis demonstrated that a significant regression equation (R2 = 0.649, P < .001) for predicting mean wrinkle depth was determined by BR at 107.1 µm depth (BR 107.1 µm ), DOPU at 170.1 µm (DOPU 170.1µm ), and AC at 252 µm (AC 252 µm ) as independent variables and that these standardized beta regression coefficients were -0.860, -0.593, and -0.440, respectively, suggesting that BR, DOPU, and AC sufficiently explained mean wrinkle depth. CONCLUSION These results suggest that BR 107.1 µm , DOPU 170.1 µm, and AC 252 µm may indicate collagen-related structure in the papillary, upper-reticular dermis, and microstructure or tissue density in reticular dermis, respectively, and may be involved in wrinkle formation.
Collapse
Affiliation(s)
- Kohei Yamazaki
- Biological Science Research, Kao Corporation, Odawara, Japan
| | - En Li
- Computational Optics Group, University of Tsukuba, Tsukuba, Japan
| | - Arata Miyazawa
- Computational Optics Group, University of Tsukuba, Tsukuba, Japan
| | | | - Tetsuya Sayo
- Biological Science Research, Kao Corporation, Odawara, Japan
| | - Shuichi Makita
- Computational Optics Group, University of Tsukuba, Tsukuba, Japan
| | | | - Yoshiaki Yasuno
- Computational Optics Group, University of Tsukuba, Tsukuba, Japan
| | - Shingo Sakai
- Skin Care Product Research, Kao Corporation, Odawara, Japan
| |
Collapse
|
24
|
Lopez AL, Wang S, Larina IV. Embryonic Mouse Cardiodynamic OCT Imaging. J Cardiovasc Dev Dis 2020; 7:E42. [PMID: 33020375 PMCID: PMC7712379 DOI: 10.3390/jcdd7040042] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/10/2020] [Accepted: 09/21/2020] [Indexed: 12/11/2022] Open
Abstract
The embryonic heart is an active and developing organ. Genetic studies in mouse models have generated great insight into normal heart development and congenital heart defects, and suggest mechanical forces such as heart contraction and blood flow to be implicated in cardiogenesis and disease. To explore this relationship and investigate the interplay between biomechanical forces and cardiac development, live dynamic cardiac imaging is essential. Cardiodynamic imaging with optical coherence tomography (OCT) is proving to be a unique approach to functional analysis of the embryonic mouse heart. Its compatibility with live culture systems, reagent-free contrast, cellular level resolution, and millimeter scale imaging depth make it capable of imaging the heart volumetrically and providing spatially resolved information on heart wall dynamics and blood flow. Here, we review the progress made in mouse embryonic cardiodynamic imaging with OCT, highlighting leaps in technology to overcome limitations in resolution and acquisition speed. We describe state-of-the-art functional OCT methods such as Doppler OCT and OCT angiography for blood flow imaging and quantification in the beating heart. As OCT is a continuously developing technology, we provide insight into the future developments of this area, toward the investigation of normal cardiogenesis and congenital heart defects.
Collapse
Affiliation(s)
- Andrew L. Lopez
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA;
| | - Shang Wang
- Department of Biomedical Engineering, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030, USA;
| | - Irina V. Larina
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA;
| |
Collapse
|
25
|
Gong P, Li Q, Wang Q, Karnowski K, Sampson DD. Jones matrix-based speckle-decorrelation angiography using polarization-sensitive optical coherence tomography. JOURNAL OF BIOPHOTONICS 2020; 13:e202000007. [PMID: 32418315 DOI: 10.1002/jbio.202000007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 04/19/2020] [Accepted: 05/13/2020] [Indexed: 05/18/2023]
Abstract
We show that polarization-sensitive optical coherence tomography angiography (PS-OCTA) based on full Jones matrix assessment of speckle decorrelation offers improved contrast and depth of vessel imaging over conventional OCTA. We determine how best to combine the individual Jones matrix elements and compare the resulting image quality to that of a conventional OCT scanner by co-locating and imaging the same skin locations with closely matched scanning setups. Vessel projection images from finger and forearm skin demonstrate the benefits of Jones matrix-based PS-OCTA. Our study provides a promising starting point and a useful reference for future pre-clinical and clinical applications of Jones matrix-based PS-OCTA.
Collapse
Affiliation(s)
- Peijun Gong
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, WA, Australia
| | - Qingyun Li
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, WA, Australia
| | - Qiang Wang
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, WA, Australia
| | - Karol Karnowski
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, WA, Australia
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - David D Sampson
- Surrey Biophotonics, Advanced Technology Institute and School of Biosciences and Medicine, University of Surrey, Surrey, UK
| |
Collapse
|
26
|
Tan B, Sim R, Chua J, Wong DWK, Yao X, Garhöfer G, Schmidl D, Werkmeister RM, Schmetterer L. Approaches to quantify optical coherence tomography angiography metrics. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:1205. [PMID: 33241054 PMCID: PMC7576021 DOI: 10.21037/atm-20-3246] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Optical coherence tomography (OCT) has revolutionized the field of ophthalmology in the last three decades. As an OCT extension, OCT angiography (OCTA) utilizes a fast OCT system to detect motion contrast in ocular tissue and provides a three-dimensional representation of the ocular vasculature in a non-invasive, dye-free manner. The first OCT machine equipped with OCTA function was approved by U.S. Food and Drug Administration in 2016 and now it is widely applied in clinics. To date, numerous methods have been developed to aid OCTA interpretation and quantification. In this review, we focused on the workflow of OCTA-based interpretation, beginning from the generation of the OCTA images using signal decorrelation, which we divided into intensity-based, phase-based and phasor-based methods. We further discussed methods used to address image artifacts that are commonly observed in clinical settings, to the algorithms for image enhancement, binarization, and OCTA metrics extraction. We believe a better grasp of these technical aspects of OCTA will enhance the understanding of the technology and its potential application in disease diagnosis and management. Moreover, future studies will also explore the use of ocular OCTA as a window to link ocular vasculature to the function of other organs such as the kidney and brain.
Collapse
Affiliation(s)
- Bingyao Tan
- Institute for Health Technologies, Nanyang Technological University, Singapore, Singapore.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,SERI-NTU Advanced Ocular Engineering (STANCE) Program, Nanyang Technological University, Singapore, Singapore
| | - Ralene Sim
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Jacqueline Chua
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
| | - Damon W K Wong
- Institute for Health Technologies, Nanyang Technological University, Singapore, Singapore.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,SERI-NTU Advanced Ocular Engineering (STANCE) Program, Nanyang Technological University, Singapore, Singapore
| | - Xinwen Yao
- Institute for Health Technologies, Nanyang Technological University, Singapore, Singapore.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,SERI-NTU Advanced Ocular Engineering (STANCE) Program, Nanyang Technological University, Singapore, Singapore
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Doreen Schmidl
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - René M Werkmeister
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Leopold Schmetterer
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,SERI-NTU Advanced Ocular Engineering (STANCE) Program, Nanyang Technological University, Singapore, Singapore.,Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore.,Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.,Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.,Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore.,Department of Ophthalmology, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.,Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
| |
Collapse
|
27
|
Liu J, Zhu J, Zhu L, Yang Q, Fan F, Zhang F. Quantitative assessment of optical coherence tomography angiography algorithms for neuroimaging. JOURNAL OF BIOPHOTONICS 2020; 13:e202000181. [PMID: 32542943 DOI: 10.1002/jbio.202000181] [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: 05/08/2020] [Revised: 06/11/2020] [Accepted: 06/11/2020] [Indexed: 06/11/2023]
Abstract
Optical coherence tomography (OCT) angiography can noninvasively map microvascular networks and quantify blood flow in a cerebral cortex with a resolution of 1 to 10 μm and a penetration depth of 2 to 3 mm incorporating OCT signals and angiography algorithms. Different angiography algorithms have been developed in recent years; however, the performance of the algorithms has not been assessed quantitatively for neuroimaging applications. In this paper, we developed four metrics including vascular connectivity, contrast-to-noise ratio, signal-to-noise ratio and processing time to quantitatively assess the performance of OCT angiography algorithms in image quality and computation speed. After the imaging of a rat cortex using an OCT system, the cerebral microvascular networks were visualized by seven algorithms, and the performance of the algorithms was quantified and compared. Quantitative performance assessment of the algorithms can provide suggestions for the selection of appropriate OCT angiography algorithms in neuroimaging.
Collapse
Affiliation(s)
- Jianting Liu
- Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument, Beijing Information Science and Technology University, Beijing, China
- Beijing Laboratory of Biomedical Testing Technology and Instruments, Beijing Information Science and Technology University, Beijing, China
| | - Jiang Zhu
- Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument, Beijing Information Science and Technology University, Beijing, China
- Beijing Laboratory of Biomedical Testing Technology and Instruments, Beijing Information Science and Technology University, Beijing, China
| | - Lianqing Zhu
- Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument, Beijing Information Science and Technology University, Beijing, China
- Beijing Key Laboratory of Optoelectronic Measurement Technology, Beijing Information Science and Technology University, Beijing, China
| | - Qiang Yang
- Beijing Laboratory of Biomedical Testing Technology and Instruments, Beijing Information Science and Technology University, Beijing, China
| | - Fan Fan
- Beijing Laboratory of Biomedical Testing Technology and Instruments, Beijing Information Science and Technology University, Beijing, China
| | - Fan Zhang
- Beijing Laboratory of Biomedical Testing Technology and Instruments, Beijing Information Science and Technology University, Beijing, China
| |
Collapse
|
28
|
Raghunathan R, Liu CH, Ambekar YS, Singh M, Miranda RC, Larin KV. Optical coherence tomography angiography to evaluate murine fetal brain vasculature changes caused by prenatal exposure to nicotine. BIOMEDICAL OPTICS EXPRESS 2020; 11:3618-3632. [PMID: 33014555 PMCID: PMC7510910 DOI: 10.1364/boe.394905] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 06/01/2020] [Accepted: 06/02/2020] [Indexed: 05/03/2023]
Abstract
Maternal smoking causes several defects ranging from intrauterine growth restriction to sudden infant death syndrome and spontaneous abortion. While several studies have documented the effects of prenatal nicotine exposure in development and behavior, acute vasculature changes in the fetal brain due to prenatal nicotine exposure have not been evaluated yet. This study uses correlation mapping optical coherence angiography to evaluate changes in fetal brain vasculature flow caused by maternal exposure to nicotine during the second trimester-equivalent of gestation in a mouse model. The effects of two different doses of nicotine were evaluated. Results showed a decrease in the vasculature for both doses of nicotine, which was not seen in the case of the sham group.
Collapse
Affiliation(s)
- Raksha Raghunathan
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Houston, TX 77204, USA
| | - Chih-Hao Liu
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Houston, TX 77204, USA
| | - Yogeshwari S Ambekar
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Houston, TX 77204, USA
| | - Manmohan Singh
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Houston, TX 77204, USA
| | - Rajesh C Miranda
- Department of Neuroscience and Experimental Therapeutics, TAMHSC College of Medicine, 8441 Riverside Parkway, Bryan, TX 77807, USA
| | - Kirill V Larin
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Houston, TX 77204, USA
- Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77206, USA
| |
Collapse
|
29
|
Schuerch K, Frech H, Zinkernagel M. Conjunctival Microangiopathy in Diabetes Mellitus Assessed with Optical Coherence Tomography Angiography. Transl Vis Sci Technol 2020; 9:10. [PMID: 32821507 PMCID: PMC7408868 DOI: 10.1167/tvst.9.6.10] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 03/12/2020] [Indexed: 02/07/2023] Open
Abstract
Purpose To detect and quantify conjunctival microangiopathy with optical coherence tomography angiography (OCTA). Methods Imaging was performed in the temporal and nasal quadrant of the conjunctiva using a Heidelberg Spectralis spectral domain-OCT in OCTA mode adding a 25D lens to the standard 30° fundus lens. Images were acquired within a 10° × 5° cube at the limbus. Binary images were analyzed using ImageJ (Fiji software version 2.0) and an average relative conjunctival vessel density was assessed. Results Thirty-two patients with diabetes mellitus type 1 and 2 and 42 healthy individuals were included. Vessel density in healthy individuals was 16.7 ± 5.2% in the nasal and 17.9 ± 6.4% in the temporal quadrant. In patients with diabetes without retinopathy, vessel density was 16.3 ± 6.7% in the nasal and 15.3 ± 7.3% in the temporal conjunctiva. In patients with diabetic retinopathy, vessel density was 13.7 ± 4.3% in the nasal and 15.2 ± 6.5% in the temporal conjunctiva. There were statistically significant higher values in both nasal and temporal measurements among healthy individuals than in patients with diabetic retinopathy (P = 0.03 and P = 0.01, respectively). Conclusions Patients with diabetic retinopathy exhibit reduced vessel density, which may suggest diabetic microangiopathy in the conjunctiva. Anterior segment OCTA may detect conjunctival microangiopathy in patients with visual axis opacifications, where retinal OCTA is not possible. Translational Relevance The findings of this study bridge the gap between experimental anterior segment OCTA imaging and clinical screening for diabetic complications.
Collapse
Affiliation(s)
- Kaspar Schuerch
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Hendrik Frech
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Martin Zinkernagel
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| |
Collapse
|
30
|
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.
Collapse
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
| |
Collapse
|
31
|
Rico-Jimenez J, Lee JH, Alex A, Musaad S, Chaney E, Barkalifa R, Spillman DR, Olson E, Adams D, Marjanovic M, Arp Z, Boppart SA. Non-invasive monitoring of pharmacodynamics during the skin wound healing process using multimodal optical microscopy. BMJ Open Diabetes Res Care 2020; 8:8/1/e000974. [PMID: 32327442 PMCID: PMC7202789 DOI: 10.1136/bmjdrc-2019-000974] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/13/2020] [Accepted: 02/22/2020] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Impaired diabetic wound healing is one of the serious complications associated with diabetes. In patients with diabetes, this impairment is characterized by several physiological abnormalities such as metabolic changes, reduced collagen production, and diminished angiogenesis. We designed and developed a multimodal optical imaging system that can longitudinally monitor formation of new blood vessels, metabolic changes, and collagen deposition in a non-invasive, label-free manner. RESEARCH DESIGN AND METHODS The closure of a skin wound in (db/db) mice, which presents delayed wound healing pathologically similar to conditions in human type 2 diabetes mellitus, was non-invasively followed using the custom-built multimodal microscope. In this microscope, optical coherence tomography angiography was used for studying neovascularization, fluorescence lifetime imaging microscopy for nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) assessment, fluorescence intensity changes of NAD(P)H and flavin adenine dinucleotide (FAD) cofactors for evaluating metabolic changes, and second harmonic generation microscopy for analyzing collagen deposition and organization. The animals were separated into four groups: control, placebo, low concentration (LC), and high concentration (HC) treatment. Images of the wound and surrounding areas were acquired at different time points during a 28-day period. RESULTS Various physiological changes measured using the optical imaging modalities at different phases of wound healing were compared. A statistically significant improvement in the functional relationship between angiogenesis, metabolism, and structural integrity was observed in the HC group. CONCLUSIONS This study demonstrated the capability of multimodal optical imaging to non-invasively monitor various physiological aspects of the wound healing process, and thus become a promising tool in the development of better diagnostic, treatment, and monitoring strategies for diabetic wound care.
Collapse
Affiliation(s)
- Jose Rico-Jimenez
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Jang Hyuk Lee
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Aneesh Alex
- GlaxoSmithKline, Philadelphia, Pennsylvania, USA
| | - Salma Musaad
- Interdisciplinary Health Sciences Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Eric Chaney
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Ronit Barkalifa
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Darold R Spillman
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Eric Olson
- GlaxoSmithKline, Philadelphia, Pennsylvania, USA
| | - David Adams
- GlaxoSmithKline, Philadelphia, Pennsylvania, USA
| | - Marina Marjanovic
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Zane Arp
- GlaxoSmithKline, Philadelphia, Pennsylvania, USA
| | - Stephen A Boppart
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| |
Collapse
|
32
|
Si P, Honkala A, de la Zerda A, Smith BR. Optical Microscopy and Coherence Tomography of Cancer in Living Subjects. Trends Cancer 2020; 6:205-222. [PMID: 32101724 DOI: 10.1016/j.trecan.2020.01.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 01/05/2020] [Accepted: 01/07/2020] [Indexed: 12/16/2022]
Abstract
Intravital microscopy (IVM) and optical coherency tomography (OCT) are two powerful optical imaging tools that allow visualization of dynamic biological activities in living subjects with subcellular resolutions. Recent advances in labeling and label-free techniques empower IVM and OCT for a wide range of preclinical and clinical cancer imaging, providing profound insights into the complex physiological, cellular, and molecular behaviors of tumors. Preclinical IVM and OCT have elucidated many otherwise inscrutable aspects of cancer biology, while clinical applications of IVM and OCT are revolutionizing cancer diagnosis and therapies. We review important progress in the fields of IVM and OCT for cancer imaging in living subjects, highlighting key technological developments and their emerging applications in fundamental cancer biology research and clinical oncology investigation.
Collapse
Affiliation(s)
- Peng Si
- Department of Structural Biology, Stanford University, Stanford, CA 94305, USA; Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA
| | - Alexander Honkala
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Adam de la Zerda
- Department of Structural Biology, Stanford University, Stanford, CA 94305, USA; Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA; Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA; The Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
| | - Bryan Ronain Smith
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA; Department of Biomedical Engineering and Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI 48824, USA.
| |
Collapse
|
33
|
Lee S, Wei S, Guo S, Kim J, Kim B, Kim G, Kang JU. Selective retina therapy monitoring by speckle variance optical coherence tomography for dosimetry control. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-9. [PMID: 32061065 PMCID: PMC7019183 DOI: 10.1117/1.jbo.25.2.026001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 01/29/2020] [Indexed: 05/29/2023]
Abstract
SIGNIFICANCE Selective retina therapy (SRT) selectively targets the retinal pigment epithelium (RPE) and reduces negative side effects by avoiding thermal damages of the adjacent photoreceptors, the neural retina, and the choroid. However, the selection of proper laser energy for the SRT is challenging because of ophthalmoscopically invisible lesions in the RPE and different melanin concentrations among patients or even regions within an eye. AIM We propose and demonstrate SRT monitoring based on speckle variance optical coherence tomography (svOCT) for dosimetry control. APPROACH M-scans, time-resolved sequence of A-scans, of ex vivo bovine retina irradiated by 1.7-μs duration laser pulses were obtained by a swept-source OCT. SvOCT images were calculated as interframe intensity variance of the sequence. Spatial and temporal temperature distributions in the retina were numerically calculated in a 2-D retinal model using COMSOL Multiphysics. Microscopic images of treated spots were obtained before and after removing the upper neural retinal layer to assess the damage in both RPE and neural layers. RESULTS SvOCT images show abrupt speckle variance changes when the retina is irradiated by laser pulses. The svOCT intensities averaged in RPE and photoreceptor layers along the axial direction show sharp peaks corresponding to each laser pulse, and the peak values were proportional to the laser pulse energy. The calculated temperatures in the neural retina layer and RPE were linearly fitted to the svOCT peak values, and the temperature of each lesion was estimated based on the fitting. The estimated temperatures matched well with previously reported results. CONCLUSION We found a reliable correlation between the svOCT peak values and the degree of retinal lesion formation, which can be used for selecting proper laser energy during SRT.
Collapse
Affiliation(s)
- Soohyun Lee
- Johns Hopkins University, Department of Electrical and Computer Engineering, Baltimore, Maryland, United States
| | - Shuwen Wei
- Johns Hopkins University, Department of Electrical and Computer Engineering, Baltimore, Maryland, United States
| | - Shoujing Guo
- Johns Hopkins University, Department of Electrical and Computer Engineering, Baltimore, Maryland, United States
| | | | | | - Gihoon Kim
- Lutronic Center, Goyang, Republic of Korea
| | - Jin U. Kang
- Johns Hopkins University, Department of Electrical and Computer Engineering, Baltimore, Maryland, United States
| |
Collapse
|
34
|
Smith KJ, Argarini R, Carter HH, Quirk BC, Haynes A, Naylor LH, McKirdy H, Kirk RW, McLaughlin RA, Green DJ. Novel Noninvasive Assessment of Microvascular Structure and Function in Humans. Med Sci Sports Exerc 2020; 51:1558-1565. [PMID: 30688767 DOI: 10.1249/mss.0000000000001898] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
INTRODUCTION Optical coherence tomography (OCT) is a novel high-resolution imaging technique capable of visualizing in vivo structures at a resolution of ~10 μm. We have developed specialized OCT-based approaches that quantify diameter, speed, and flow rate in human cutaneous microvessels. In this study, we hypothesized that OCT-based microvascular assessments would possess comparable levels of reliability when compared with those derived using conventional laser Doppler flowmetry (LDF). METHODS Speckle decorrelation images (OCT) and red blood cell flux (LDF) measures were collected from adjacent forearm skin locations on 2 d (48 h apart), at baseline, and after a 30-min rapid local heating protocol (30°C-44°C) in eight healthy young individuals. OCT postprocessing quantified cutaneous microvascular diameter, speed, flow rate, and density (vessel recruitment) within a region of interest, and data were compared between days. RESULTS Forearm skin LDF (13 ± 4 to 182 ± 31 AU, P < 0.05) and OCT-derived diameter (41.8 ± 6.6 vs 64.5 ± 6.9 μm), speed (68.4 ± 9.5 vs 89.0 ± 7.3 μm·s), flow rate (145.0 ± 60.6 vs 485 ± 132 pL·s), and density (9.9% ± 4.9% vs 45.4% ± 5.9%) increased in response to local heating. The average OCT-derived microvascular flow response (pL·s) to heating (234% increase) was lower (P < 0.05) than the LDF-derived change (AU) (1360% increase). Pearson correlation was significant for between-day local heating responses in terms of OCT flow (r = 0.93, P < 0.01), but not LDF (P = 0.49). Bland-Altman analysis revealed that between-day baseline OCT-derived flow rates were less variable than LDF-derived flux. CONCLUSIONS Our findings indicate that OCT, which directly visualizes human microvessels, not only allows microvascular quantification of diameter, speed, flow rate, and vessel recruitment but also provides outputs that are highly reproducible. OCT is a promising novel approach that enables a comprehensive assessment of cutaneous microvascular structure and function in humans.
Collapse
Affiliation(s)
- Kurt J Smith
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), Faculty of Science, The University of Western Australia, Perth, AUSTRALIA.,School of Kinesiology, Faculty of Health and Behavioural Science, Lakehead University, Thunderbay, Ontario, CANADA
| | - Raden Argarini
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), Faculty of Science, The University of Western Australia, Perth, AUSTRALIA.,Department of Physiology, Faculty of Medicine, Airlangga University, Surabaya, INDONESIA
| | - Howard H Carter
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), Faculty of Science, The University of Western Australia, Perth, AUSTRALIA
| | - Bryden C Quirk
- Australian Research Council Centre of Excellence for Nanoscale Biophotonics, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, AUSTRALIA.,Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, AUSTRALIA
| | - Andrew Haynes
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), Faculty of Science, The University of Western Australia, Perth, AUSTRALIA
| | - Louise H Naylor
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), Faculty of Science, The University of Western Australia, Perth, AUSTRALIA
| | - Hamish McKirdy
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), Faculty of Science, The University of Western Australia, Perth, AUSTRALIA
| | - Rodney W Kirk
- Australian Research Council Centre of Excellence for Nanoscale Biophotonics, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, AUSTRALIA.,Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, AUSTRALIA
| | - Robert A McLaughlin
- Australian Research Council Centre of Excellence for Nanoscale Biophotonics, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, AUSTRALIA.,Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, AUSTRALIA.,School of Electrical, Electronic and Computer Engineering, Faculty of Engineering and Mathematical Sciences, The University of Western Australia, Perth, AUSTRALIA
| | - Daniel J Green
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), Faculty of Science, The University of Western Australia, Perth, AUSTRALIA
| |
Collapse
|
35
|
Wang TA, Chan MC, Lee HC, Lee CY, Tsai MT. Ultrahigh-resolution optical coherence tomography/angiography with an economic and compact supercontinuum laser. BIOMEDICAL OPTICS EXPRESS 2019; 10:5687-5702. [PMID: 31799040 PMCID: PMC6865110 DOI: 10.1364/boe.10.005687] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 10/06/2019] [Accepted: 10/07/2019] [Indexed: 05/19/2023]
Abstract
In this study, a Q-switch pumped supercontinuum laser (QS-SCL) is used as a light source for in vivo imaging via ultrahigh-resolution optical coherence tomography and angiography (UHR-OCT/OCTA). For this purpose, an OCT system based on a spectral-domain detection scheme is constructed, and a spectrometer with a spectral range of 635 - 875 nm is designed. The effective full-width at half maximum of spectrum covers 150 nm, and the corresponding axial and transverse resolutions are 2 and 10 µm in air, respectively. The relative intensity noise of the QS-SCL and mode-locked SCL is quantitatively compared. Furthermore, a special processing algorithm is developed to eliminate the intrinsic noise of QS-SCL. This work demonstrates that QS-SCLs can effectively reduce the cost and size of UHR-OCT/OCTA instruments, making clinical applications feasible.
Collapse
Affiliation(s)
- Tai-Ang Wang
- Institute of Photonic System, College of Photonics, National Chiao-Tung University, Tainan City 71150, Taiwan
- The authors contributed equally to this work
| | - Ming-Che Chan
- Institute of Photonic System, College of Photonics, National Chiao-Tung University, Tainan City 71150, Taiwan
- The authors contributed equally to this work
| | - Hsiang-Chieh Lee
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, 10617, Taiwan
- Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Cheng-Yu Lee
- Department of Electrical Engineering, Chang Gung University, Taoyuan 33302, Taiwan
| | - Meng-Tsan Tsai
- Department of Electrical Engineering, Chang Gung University, Taoyuan 33302, Taiwan
- Department of Neurosurgery, Chang Gung Memorial Hospital, Linkou, Taoyuan 33305, Taiwan
| |
Collapse
|
36
|
Argarini R, McLaughlin RA, Naylor LH, Carter HH, Green DJ. Assessment of the human cutaneous microvasculature using optical coherence tomography: Proving Harvey's proof. Microcirculation 2019; 27:e12594. [PMID: 31585482 DOI: 10.1111/micc.12594] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/05/2019] [Accepted: 09/18/2019] [Indexed: 12/15/2022]
Abstract
William Harvey proved the circulation of blood 400 years ago using a combination of ligature application and astute observation that presaged the existence of capillaries. Here we report findings, based on our development of a novel application of optical coherence tomography (OCT), that directly confirm the impact of cuff inflation on microvessels as small as ~30µm. By emulating Harvey's proofs, using cuff inflation at low pressure in the presence and absence of skin heating, we have imaged and quantified significant effects on microvascular diameter and density in humans in vivo. The application of cuff pressure significantly increased microvascular diameter (40.5 ± 4.6 vs 47.1 ± 3.9 µm, P = .01) and density (8.33 ± 4.3 vs 15.1 ± 4.9%, P < .01). These impacts were reversed by cuff deflation. Our study also showed the profound impacts of skin heating on microvessel diameter (46.7 ± 5.8 vs 70.6 ± 7.8 µm, P < .01) and density (14.2 ± 6.5 vs 43.2 ± 9%, P < .01) in vivo, which were further exacerbated by cuff inflation. Our approach to the direct visualization of the human skin microvasculature is non-invasive, safe, and easily applied. Future experiments might be directed at questions of microvascular physiology and pathophysiology, such as how different mammals thermoregulate and what impacts cardiovascular disease and diabetes have on microvascular structure and function.
Collapse
Affiliation(s)
- Raden Argarini
- Physiology Department, Faculty of Medicine, Airlangga University, Surabaya, Indonesia.,Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, WA, Australia
| | - Robert A McLaughlin
- Faculty of Health and Medical Sciences, Australian Research Council Centre of Excellence for Nanoscale Biophotonics, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia.,Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, SA, Australia
| | - Louise H Naylor
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, WA, Australia
| | - Howard H Carter
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, WA, Australia
| | - Daniel J Green
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, WA, Australia
| |
Collapse
|
37
|
Kim JT, Chun YS, Lee JK, Moon NJ, Yi DY. Comparison of Vessel Density Reduction in the Deep and Superficial Capillary Plexuses in Branch Retinal Vein Occlusion. Ophthalmologica 2019; 243:66-74. [PMID: 31618738 DOI: 10.1159/000502385] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 07/29/2019] [Indexed: 11/19/2022]
Abstract
PURPOSE To quantify the susceptibility of the deep capillary plexus (DCP) in comparison with that of the superficial capillary plexus (SCP) in eyes with branch retinal vein occlusion (BRVO) using swept-source optical coherence tomography angiography (SS-OCTA). METHODS SS-OCTA (TritonTM; Topcon, Tokyo, Japan) scans (3 × 3 mm) of 41 patients with BRVO were retrospectively analyzed. The mean vessel densities (VDs) of the SCP and the DCP were calculated in eyes with BRVO using the ImageJ program (National Institutes of Health, Bethesda, MD, USA) and compared with those in the normal fellow eye without any morbidity or unaffected sector in the BRVO eye. RESULTS The reduction rate of mean VD in SCP and DCP between the affected and unaffected sector of eyes with BRVO was 13.88 and 24.60%, respectively. Additionally, the reduction rate of mean VD in the SCP and DCP in the affected sector of BRVO eyes versus the corresponding sector of fellow eyes was 13.31 and 24.49%, respectively. CONCLUSION The DCP was 1.77-1.84 times more affected than the SCP by ischemic damage in eyes with BRVO.
Collapse
Affiliation(s)
- Jee Taek Kim
- Department of Ophthalmology, College of Medicine, Chung-Ang University Hospital, Seoul, Republic of Korea,
| | - Yeon Sook Chun
- Department of Ophthalmology, College of Medicine, Chung-Ang University Hospital, Seoul, Republic of Korea
| | - Jeong Kyu Lee
- Department of Ophthalmology, College of Medicine, Chung-Ang University Hospital, Seoul, Republic of Korea
| | - Nam Ju Moon
- Department of Ophthalmology, College of Medicine, Chung-Ang University Hospital, Seoul, Republic of Korea
| | - Dae Yong Yi
- Department of Pediatrics, College of Medicine, Chung-Ang University Hospital, Seoul, Republic of Korea
| |
Collapse
|
38
|
Guo S, Wei S, Lee S, Sheu M, Kang S, Kang JU. Intraoperative Speckle Variance Optical Coherence Tomography for Tissue Temperature Monitoring During Cutaneous Laser Therapy. IEEE JOURNAL OF TRANSLATIONAL ENGINEERING IN HEALTH AND MEDICINE 2019; 7:1800608. [PMID: 32309052 PMCID: PMC6788854 DOI: 10.1109/jtehm.2019.2943317] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/13/2019] [Accepted: 09/19/2019] [Indexed: 01/18/2023]
Abstract
Background: Tissue temperature monitoring during cutaneous laser therapy can lead to safer and more effective treatments. In this study, we investigate the use of speckle variance optical coherence tomography (svOCT) to monitor real-time temperature changes in the excised human skin tissue sample during laser irradiation. Methods: To accomplish this, we combined the pulse laser system with a reference-based svOCT system. To calibrate the svOCT, the ex-vivo human skin samples from three individuals with tissues collected from the arm, face, and back were heated with 1-degree increments. Additionally, linear regression was used to extract and evaluate the linear relationship between the temperature and normalized speckle variance value. Experiments were conducted on excised human skin sample to monitor the temperature change during laser therapy with a svOCT system. Thermal modeling of ex-vivo human skin was used to numerically simulate the laser-tissue interaction and estimate the thermal diffusion and peak temperature of the tissue during the laser treatment. Results and Conclusion: These results showed that normalized speckle variance had a linear relationship with the tissue temperature before the onset of tissue coagulation (52°) and we were able to measure the rapid increase of the tissue temperature during laser therapy. The result of the experiment is also in good agreement with the numerical simulation result that estimated the laser-induced peak temperature and thermal relaxation time.
Collapse
Affiliation(s)
- Shoujing Guo
- Electrical and Computer Engineering DepartmentJohns Hopkins UniversityBaltimoreMD21218USA
| | - Shuwen Wei
- Electrical and Computer Engineering DepartmentJohns Hopkins UniversityBaltimoreMD21218USA
| | - Soohyun Lee
- Electrical and Computer Engineering DepartmentJohns Hopkins UniversityBaltimoreMD21218USA
| | - Mary Sheu
- Department of DermatologyJohns Hopkins Medicine - Green Spring StationLuthervilleMD21093USA
| | - Sewon Kang
- Department of DermatologyThe Johns Hopkins HospitalBaltimoreMD21287USA
| | - Jin U. Kang
- Electrical and Computer Engineering DepartmentJohns Hopkins UniversityBaltimoreMD21218USA
| |
Collapse
|
39
|
Zhang W, Qin Y, Xie X, Hu Z, Paulus YM, Yang X, Wang X. Real-time photoacoustic sensing for photo-mediated ultrasound therapy. OPTICS LETTERS 2019; 44:4063-4066. [PMID: 31415547 PMCID: PMC6907727 DOI: 10.1364/ol.44.004063] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 07/10/2019] [Indexed: 06/01/2023]
Abstract
Photo-mediated ultrasound therapy (PUT) is a novel, noninvasive antimicrovascular approach that can treat neovascularization with high precision. We developed a photoacoustic (PA) sensing (PAS) system for PUT and achieved real-time PAS-guided PUT. Experiments performed on a chicken yolk sac membrane model demonstrated that PAS could monitor the treatment effect in a microvessel during PUT. Vessel shrinkage induced a decrease in the PA signal amplitude, while vessel rupture induced an abrupt increase in the PA signal amplitude. The integrated PUT and PAS system can significantly improve the safety and effectiveness of PUT, and may assist with clinical translation of this novel antimicrovascular technique.
Collapse
Affiliation(s)
- Wei Zhang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Yu Qin
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Institute of Acoustics, School of Physics Science and Engineering, Tongji University, Shanghai, P. R. China
| | - Xinyi Xie
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, P.R. China
| | - Zizhong Hu
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, P.R. China
| | - Yannis M Paulus
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Xinmai Yang
- Institute for Bioengineering Research and Department of Mechanical Engineering, University of Kansas, Lawrence, KS, USA
| | - Xueding Wang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
40
|
Raghunathan R, Liu CH, Kouka A, Singh M, Miranda RC, Larin KV. Assessing the acute effects of prenatal synthetic cannabinoid exposure on murine fetal brain vasculature using optical coherence tomography. JOURNAL OF BIOPHOTONICS 2019; 12:e201900050. [PMID: 30887665 PMCID: PMC10039318 DOI: 10.1002/jbio.201900050] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/15/2019] [Accepted: 03/17/2019] [Indexed: 05/02/2023]
Abstract
Marijuana is one of the most commonly abused substances during pregnancy. Synthetic cannabinoids (SCBs) are a group of heterogeneous compounds that are 40- to 600-fold more potent than Δ9 -tetrahydrocannabinol, the major psychoactive component of marijuana. With SCBs being legally available for purchase and the prevalence of unplanned pregnancies, the possibility of prenatal exposure to SCBs is high. However, the effects of prenatal SCB exposure on embryonic brain development are not well understood. In this study, we use complex correlation mapping optical coherence angiography to evaluate changes in murine fetal brain vasculature in utero, minutes after maternal exposure to an SCB, CP-55940. Results showed a significant decrease (P < 0.05) in fetal brain vessel diameter, length fraction and area density when compared to the sham group. This preliminary study shows that acute prenatal exposure to an SCB resulted in significant fetal brain vasoconstriction during the peak period for brain development.
Collapse
Affiliation(s)
- Raksha Raghunathan
- Department of Biomedical Engineering, University of Houston, Houston, Texas
| | - Chih-Hao Liu
- Department of Biomedical Engineering, University of Houston, Houston, Texas
| | - Amur Kouka
- Department of Biomedical Engineering, University of Houston, Houston, Texas
| | - Manmohan Singh
- Department of Biomedical Engineering, University of Houston, Houston, Texas
| | - Rajesh C. Miranda
- Department of Neuroscience and Experimental Therapeutics, TAMHSC College of Medicine, Bryan, Texas
| | - Kirill V. Larin
- Department of Biomedical Engineering, University of Houston, Houston, Texas
- Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas
- Correspondence: Kirill V. Larin, Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Houston, TX 77204.
| |
Collapse
|
41
|
Alnawaiseh M, Brand C, Lauermann JL, Eter N. [Flow density measurements using optical coherence tomography angiography : Impact of age and gender]. Ophthalmologe 2019; 115:659-662. [PMID: 28726070 DOI: 10.1007/s00347-017-0539-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND This article presents the normative data for flow density measured using optical coherence tomography (OCT) angiography and the impact of age and gender is evaluated. METHODS In this study 58 eyes from 58 healthy volunteers with no history of any ocular disease or ocular surgery were included. The OCT angiography imaging was performed using the RTVue XR Avanti with the AngioVue (Optovue, Fremont, CA). The macula was imaged using a 3 × 3 mm scan, and the flow density data in the superficial retinal OCT angiogram and deep retinal OCT angiogram were extracted and analyzed. The groups were compared using the Mann-Whitney U‑test and the degree of correlation between two variables was expressed as the Spearman's correlation coefficient (rSp.) RESULTS: The mean subject age was 38.3 ± 14.6 years. The flow density (whole en face) in the deep retinal OCT angiogram was significantly higher compared to the flow density in the superficial retinal OCT angiogram (p < 0.001). There was no significant difference in the mean flow density in superficial and deep OCT angiograms of the macula between males (n = 27) and females (n = 31). There was a significant correlation between the flow density in the deep retinal OCT angiogram and age (rSp. = -0.41, p = 0.001). CONCLUSION Whereas gender has no impact on the flow density measured using OCT angiography, there was a significant correlation between the flow density in the deep retinal OCT angiogram and age.
Collapse
Affiliation(s)
- M Alnawaiseh
- Universitäts-Augenklinik Münster, Domagkstr.15, 48149, Münster, Deutschland.
| | - C Brand
- Centrum für Reproduktionsmedizin und Andrologie, Universitätsklinikum Münster, Münster, Deutschland
| | - J L Lauermann
- Universitäts-Augenklinik Münster, Domagkstr.15, 48149, Münster, Deutschland
| | - N Eter
- Universitäts-Augenklinik Münster, Domagkstr.15, 48149, Münster, Deutschland
| |
Collapse
|
42
|
Li W, Li P, Fang Y, Lei TC, Dong K, Zou J, Gong W, Xie S, Huang Z. Quantitative assessment of skin swelling using optical coherence tomography. Photodiagnosis Photodyn Ther 2019; 26:413-419. [DOI: 10.1016/j.pdpdt.2019.04.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 04/29/2019] [Accepted: 04/29/2019] [Indexed: 10/26/2022]
|
43
|
Optical coherence tomography angiography for noninvasive evaluation of angiogenesis in a limb ischemia mouse model. Sci Rep 2019; 9:5980. [PMID: 30979948 PMCID: PMC6461622 DOI: 10.1038/s41598-019-42520-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 04/02/2019] [Indexed: 01/15/2023] Open
Abstract
We developed an optical coherence tomography angiography technique by improving the speckle contrast algorithm and the imaging process. This technique, which can achieve angiogenesis imaging in vivo without increasing trauma, was used to evaluate the microvasculature in limb ischemia mice. Sixteen left hindlimb ischemia mice were randomly allocated into CuSO4 and saline groups. Within 7 days after treatment, limb ischemic damage, temperature and histological staining were assessed by traditional methods. In addition, angiogenesis was evaluated using an optical coherence tomography angiography system in vivo. All results were compared. After 7 days of treatment, both the ischemic tissue damage score and temperature ratio of the CuSO4 group were significantly higher than those of the control group (all P < 0.05). The number of CD31-positive endothelial cells in the CuSO4 group (0.1836 ± 0.0153) was significantly greater than that in the saline control group (0.0436 ± 0.0069) (P < 0.001). Optical coherence tomography angiography showed that the vessel area density of mice in the CuSO4 group (0.2566 ± 0.0060) was significantly greater than that of mice in the control group (0.2079 ± 0.0202) (P = 0.027). Optical coherence tomography angiography represents a practical and effective method for observing angiogenesis in the mouse hindlimb in vivo without increasing trauma.
Collapse
|
44
|
Generating retinal flow maps from structural optical coherence tomography with artificial intelligence. Sci Rep 2019; 9:5694. [PMID: 30952891 PMCID: PMC6450899 DOI: 10.1038/s41598-019-42042-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 03/14/2019] [Indexed: 11/14/2022] Open
Abstract
Despite advances in artificial intelligence (AI), its application in medical imaging has been burdened and limited by expert-generated labels. We used images from optical coherence tomography angiography (OCTA), a relatively new imaging modality that measures retinal blood flow, to train an AI algorithm to generate flow maps from standard optical coherence tomography (OCT) images, exceeding the ability and bypassing the need for expert labeling. Deep learning was able to infer flow from single structural OCT images with similar fidelity to OCTA and significantly better than expert clinicians (P < 0.00001). Our model allows generating flow maps from large volumes of previously collected OCT data in existing clinical trials and clinical practice. This finding demonstrates a novel application of AI to medical imaging, whereby subtle regularities between different modalities are used to image the same body part and AI is used to generate detailed inferences of tissue function from structure imaging.
Collapse
|
45
|
Leng Y, Tam EK, Falavarjani KG, Tsui I. Effect of Age and Myopia on Retinal Microvasculature. Ophthalmic Surg Lasers Imaging Retina 2019; 49:925-931. [PMID: 30566699 DOI: 10.3928/23258160-20181203-03] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 11/02/2018] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVE To investigate the effect of age and refractive error on changes in the retinal microvascular network. PATIENTS AND METHODS Subjects were recruited from the Doheny Eye Institute. Refractive error and axial length were measured. High myopia was defined as refractive error greater than -6 diopters (D). Optical coherence tomography angiography (OCTA) imaging was performed and images were analyzed using fractal analysis. Primary outcomes were superficial capillary plexus (SCP) vessel density, deep capillary plexus (DCP) vessel density, and foveal avascular zone (FAZ) area. RESULTS One hundred thirty-eight eyes of 69 subjects were included. Twenty-eight (41%) subjects were male and 41 (59%) subjects were female. Mean age was 42.81 years ± 19.91 years (range: 8 years to 87 years). Mean refractive error was -1.74 D ± 3.18 D (range: -15.78 D to 4.25 D), and mean axial length (AL) was 24.29 mm ± 1.35 mm (range: 21.73 mm to 28.32 mm). SCP and DCP vessel densities were negatively correlated to age (r = -0.22, P = .011; and r = -0.49, P < .001). Controlling for age, patients with high myopia and longer AL had decreased SCP density (P = .021 and P = .027, respectively), but no difference in DCP vessel density was observed (P = .065 and P = .058, respectively). FAZ area was not significantly correlated to age, gender, refraction, or AL. CONCLUSIONS SCP and DCP vessel densities decreased with age. In addition, SCP density but not DCP vessel density was reduced in eyes with high myopia and longer AL. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:925-931.].
Collapse
|
46
|
Corliss BA, Mathews C, Doty R, Rohde G, Peirce SM. Methods to label, image, and analyze the complex structural architectures of microvascular networks. Microcirculation 2019; 26:e12520. [PMID: 30548558 PMCID: PMC6561846 DOI: 10.1111/micc.12520] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 10/31/2018] [Accepted: 11/26/2018] [Indexed: 12/30/2022]
Abstract
Microvascular networks play key roles in oxygen transport and nutrient delivery to meet the varied and dynamic metabolic needs of different tissues throughout the body, and their spatial architectures of interconnected blood vessel segments are highly complex. Moreover, functional adaptations of the microcirculation enabled by structural adaptations in microvascular network architecture are required for development, wound healing, and often invoked in disease conditions, including the top eight causes of death in the Unites States. Effective characterization of microvascular network architectures is not only limited by the available techniques to visualize microvessels but also reliant on the available quantitative metrics that accurately delineate between spatial patterns in altered networks. In this review, we survey models used for studying the microvasculature, methods to label and image microvessels, and the metrics and software packages used to quantify microvascular networks. These programs have provided researchers with invaluable tools, yet we estimate that they have collectively attained low adoption rates, possibly due to limitations with basic validation, segmentation performance, and nonstandard sets of quantification metrics. To address these existing constraints, we discuss opportunities to improve effectiveness, rigor, and reproducibility of microvascular network quantification to better serve the current and future needs of microvascular research.
Collapse
Affiliation(s)
- Bruce A Corliss
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Corbin Mathews
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Richard Doty
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Gustavo Rohde
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Shayn M Peirce
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| |
Collapse
|
47
|
Relationship between the morphology of the foveal avascular zone and the degree of aniseikonia before and after vitrectomy in patients with unilateral epiretinal membrane. Graefes Arch Clin Exp Ophthalmol 2019; 257:507-515. [DOI: 10.1007/s00417-019-04245-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 12/30/2018] [Accepted: 01/08/2019] [Indexed: 01/29/2023] Open
|
48
|
Wang Q, Gong P, Cense B, Sampson DD. Short-time series optical coherence tomography angiography and its application to cutaneous microvasculature. BIOMEDICAL OPTICS EXPRESS 2019; 10:293-307. [PMID: 30775101 PMCID: PMC6363186 DOI: 10.1364/boe.10.000293] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 11/14/2018] [Accepted: 11/28/2018] [Indexed: 05/25/2023]
Abstract
We present a new optical coherence tomography (OCT) angiography method for imaging tissue microvasculature in vivo based on the characteristic frequency-domain flow signature in a short time series of a single voxel. The angiography signal is generated by Fourier transforming the OCT signal time series from a given voxel in multiple acquisitions and computing the average magnitude of non-zero (high-pass) frequency components. Larger temporal variations of the OCT signal caused by blood flow result in higher values of the average magnitude in the frequency domain compared to those from static tissue. Weighting of the signal by the inverse of the zero-frequency component (i.e., the sum of the OCT signal time series) improves vessel contrast in flow regions of low OCT signal. The method is demonstrated on a fabricated flow phantom and on human skin in vivo and, at only 5 time points per voxel, shows enhanced vessel contrast in comparison to conventional correlation mapping/speckle decorrelation and speckle variance methods.
Collapse
Affiliation(s)
- Qiang Wang
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Perth WA 6009, Australia
| | - Peijun Gong
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Perth WA 6009, Australia
| | - Barry Cense
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Perth WA 6009, Australia
| | - David D. Sampson
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Perth WA 6009, Australia
- University of Surrey, Guildford, Surrey, GU2 7XH, UK
| |
Collapse
|
49
|
Ramakonar H, Quirk BC, Kirk RW, Li J, Jacques A, Lind CRP, McLaughlin RA. Intraoperative detection of blood vessels with an imaging needle during neurosurgery in humans. SCIENCE ADVANCES 2018; 4:eaav4992. [PMID: 30585293 PMCID: PMC6300404 DOI: 10.1126/sciadv.aav4992] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 11/20/2018] [Indexed: 05/05/2023]
Abstract
Intracranial hemorrhage can be a devastating complication associated with needle biopsies of the brain. Hemorrhage can occur to vessels located adjacent to the biopsy needle as tissue is aspirated into the needle and removed. No intraoperative technology exists to reliably identify blood vessels that are at risk of damage. To address this problem, we developed an "imaging needle" that can visualize nearby blood vessels in real time. The imaging needle contains a miniaturized optical coherence tomography probe that allows differentiation of blood flow and tissue. In 11 patients, we were able to intraoperatively detect blood vessels (diameter, >500 μm) with a sensitivity of 91.2% and a specificity of 97.7%. This is the first reported use of an optical coherence tomography needle probe in human brain in vivo. These results suggest that imaging needles may serve as a valuable tool in a range of neurosurgical needle interventions.
Collapse
Affiliation(s)
- Hari Ramakonar
- Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
- School of Surgery, University of Western Australia, Crawley, Western Australia, Australia
| | - Bryden C. Quirk
- ARC Centre of Excellence for Nanoscale Biophotonics, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
- Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, South Australia, Australia
| | - Rodney W. Kirk
- ARC Centre of Excellence for Nanoscale Biophotonics, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
- Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, South Australia, Australia
| | - Jiawen Li
- ARC Centre of Excellence for Nanoscale Biophotonics, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
- Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, South Australia, Australia
| | - Angela Jacques
- Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
- Institute for Health Research, University of Notre Dame, Fremantle, Western Australia, Australia
| | - Christopher R. P. Lind
- Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
- School of Surgery, University of Western Australia, Crawley, Western Australia, Australia
| | - Robert A. McLaughlin
- ARC Centre of Excellence for Nanoscale Biophotonics, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
- Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, South Australia, Australia
- Corresponding author.
| |
Collapse
|
50
|
Alnawaiseh M, Lahme L, Eter N, Mardin C. [Optical coherence tomography angiography: Value for glaucoma diagnostics]. Ophthalmologe 2018; 116:602-609. [PMID: 30413870 DOI: 10.1007/s00347-018-0815-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Optical coherence tomography angiography (OCTA) is a novel noninvasive method which enables a quantitative evaluation of retinal and optic nerve head (ONH) perfusion. In this article, we discuss the principles of the application of OCTA and give a summary of the knowledge gained by using this method in glaucoma patients. METHODS This article is based on a selective literature search and the analysis of own data. RESULTS Quantitative OCTA parameters have a good reproducibility in glaucoma patients. Glaucoma patients show a reduced flow density (FD) in the ONH and in the area of the macula compared with a healthy control group. The FD parameters show a good diagnostic discriminatory power but are not superior to the structural parameters used in routine diagnostics. The reduced FD measured using OCTA correlates with the extent of functional and structural glaucoma damage. CONCLUSION The OCTA is noninvasive, fast and reproducible. Initial results from studies on glaucoma patients show the high diagnostic potential of this method. The OCTA could become a part of clinical glaucoma management in the future.
Collapse
Affiliation(s)
- M Alnawaiseh
- Klinik für Augenheilkunde, Universitätsklinikum Münster, Domagkstr. 15, 48149, Münster, Deutschland.
| | - L Lahme
- Klinik für Augenheilkunde, Universitätsklinikum Münster, Domagkstr. 15, 48149, Münster, Deutschland
| | - N Eter
- Klinik für Augenheilkunde, Universitätsklinikum Münster, Domagkstr. 15, 48149, Münster, Deutschland
| | - C Mardin
- Klinik für Augenheilkunde, Universitätsklinikum Erlangen, Erlangen, Deutschland
| |
Collapse
|