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Klufts M, Jiménez AM, Lotz S, Bashir MA, Pfeiffer T, Mlynek A, Wieser W, Chamorovskiy A, Bradu A, Podoleanu A, Huber R. 828 kHz retinal imaging with an 840 nm Fourier domain mode locked laser. BIOMEDICAL OPTICS EXPRESS 2023; 14:6493-6508. [PMID: 38420314 PMCID: PMC10898573 DOI: 10.1364/boe.504302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/08/2023] [Accepted: 11/16/2023] [Indexed: 03/02/2024]
Abstract
This paper presents a Fourier domain mode locked (FDML) laser centered around 840 nm. It features a bidirectional sweep repetition rate of 828 kHz and a spectral bandwidth of 40 nm. An axial resolution of ∼9.9 µm in water and a 1.4 cm sensitivity roll-off are achieved. Utilizing a complex master-slave (CMS) recalibration method and due to a sufficiently high sensitivity of 84.6 dB, retinal layers of the human eye in-vivo can be resolved during optical coherence tomography (OCT) examination. The developed FDML laser enables acquisition rates of 3D-volumes with a size of 200 × 100 × 256 voxels in under 100 milliseconds. Detailed information on the FDML implementation, its challenging design tasks, and OCT images obtained with the laser are presented in this paper.
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Affiliation(s)
- Marie Klufts
- Institute of Biomedical Optics, University of Lübeck, Lübeck 23562, Germany
| | | | - Simon Lotz
- Institute of Biomedical Optics, University of Lübeck, Lübeck 23562, Germany
| | | | | | | | | | | | - Adrian Bradu
- School of Physical Sciences, University of Kent, Canterbury CT2 7NH, United Kingdom
| | - Adrian Podoleanu
- School of Physical Sciences, University of Kent, Canterbury CT2 7NH, United Kingdom
| | - Robert Huber
- Institute of Biomedical Optics, University of Lübeck, Lübeck 23562, Germany
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2
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Liu X, Jiang L, Ke M, Sigal IA, Chua J, Hoang QV, Chia AW, Najjar RP, Tan B, Cheong J, Bellemo V, Chong RS, Girard MJA, Ang M, Liu M, Garhöfer G, Barathi VA, Saw SM, Villiger M, Schmetterer L. Posterior scleral birefringence measured by triple-input polarization-sensitive imaging as a biomarker of myopia progression. Nat Biomed Eng 2023; 7:986-1000. [PMID: 37365268 PMCID: PMC10427432 DOI: 10.1038/s41551-023-01062-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 05/30/2023] [Indexed: 06/28/2023]
Abstract
In myopic eyes, pathological remodelling of collagen in the posterior sclera has mostly been observed ex vivo. Here we report the development of triple-input polarization-sensitive optical coherence tomography (OCT) for measuring posterior scleral birefringence. In guinea pigs and humans, the technique offers superior imaging sensitivities and accuracies than dual-input polarization-sensitive OCT. In 8-week-long studies with young guinea pigs, scleral birefringence was positively correlated with spherical equivalent refractive errors and predicted the onset of myopia. In a cross-sectional study involving adult individuals, scleral birefringence was associated with myopia status and negatively correlated with refractive errors. Triple-input polarization-sensitive OCT may help establish posterior scleral birefringence as a non-invasive biomarker for assessing the progression of myopia.
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Affiliation(s)
- Xinyu Liu
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE) programme, Singapore, Singapore
| | - Liqin Jiang
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
| | - Mengyuan Ke
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Ian A Sigal
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jacqueline Chua
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE) programme, Singapore, Singapore
| | - Quan V Hoang
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine National University of Singapore, Singapore, Singapore
- Department of Ophthalmology, Columbia University, New York, NY, USA
| | - Audrey Wi Chia
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
| | - Raymond P Najjar
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine National University of Singapore, Singapore, Singapore
| | - Bingyao Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE) programme, Singapore, Singapore
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
| | - Jocelyn Cheong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
| | - Valentina Bellemo
- SERI-NTU Advanced Ocular Engineering (STANCE) programme, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Rachel S Chong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
| | - Michaël J A Girard
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
- Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
| | - Marcus Ang
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
| | - Mengyang Liu
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Veluchamy A Barathi
- Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine National University of Singapore, Singapore, Singapore
- Translational Pre-Clinical Model Platform, Singapore Eye Research Institute, Singapore, Singapore
| | - Seang-Mei Saw
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
- Saw Swee Hock School of Public Health, ,National University of Singapore, National University Health System, Singapore, Singapore
| | - Martin Villiger
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, Boston, MA, USA
| | - Leopold Schmetterer
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.
- Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore.
- SERI-NTU Advanced Ocular Engineering (STANCE) programme, Singapore, Singapore.
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore.
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
- Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland.
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
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3
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Nam AS, Braaf B, Vakoc BJ. Using the dynamic forward scattering signal for optical coherence tomography based blood flow quantification. OPTICS LETTERS 2022; 47:3083-3086. [PMID: 35709056 PMCID: PMC9580005 DOI: 10.1364/ol.455475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
To our knowledge, all existing optical coherence tomography approaches for quantifying blood flow, whether Doppler-based or decorrelation-based, analyze light that is back-scattered by moving red blood cells (RBCs). This work investigates the potential advantages of basing these measurements on light that is forward-scattered by RBCs, i.e., by looking at the signals back-scattered from below the vessel. We show experimentally that flowmetry based on forward-scattering is insensitive to vessel orientation for vessels that are approximately orthogonal to the imaging beam. We further provide proof-of-principle demonstrations of dynamic forward-scattering (DFS) flowmetry in human retinal and choroidal vessels.
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Affiliation(s)
- Ahhyun Stephanie Nam
- Wellman Center for Photomedicine, Massachusetts General Hospital, 40 Blossom St, Boston, MA 02114 USA
- Harvard Medical School, 25 Shattuck St, Boston, MA 02115 USA
| | - Boy Braaf
- Wellman Center for Photomedicine, Massachusetts General Hospital, 40 Blossom St, Boston, MA 02114 USA
- Harvard Medical School, 25 Shattuck St, Boston, MA 02115 USA
| | - Benjamin J. Vakoc
- Wellman Center for Photomedicine, Massachusetts General Hospital, 40 Blossom St, Boston, MA 02114 USA
- Harvard Medical School, 25 Shattuck St, Boston, MA 02115 USA
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High speed, long range, deep penetration swept source OCT for structural and angiographic imaging of the anterior eye. Sci Rep 2022; 12:992. [PMID: 35046423 PMCID: PMC8770693 DOI: 10.1038/s41598-022-04784-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 12/13/2021] [Indexed: 11/24/2022] Open
Abstract
This study reports the development of prototype swept-source optical coherence tomography (SS-OCT) technology for imaging the anterior eye. Advances in vertical-cavity surface-emitting laser (VCSEL) light sources, signal processing, optics and mechanical designs, enable a unique combination of high speed, long range, and deep penetration that addresses the challenges of anterior eye imaging. We demonstrate SS-OCT with a 325 kHz A-scan rate, 12.2 µm axial resolution (in air), and 15.5 mm depth range (in air) at 1310 nm wavelength. The ultrahigh 325 kHz A-scan rate not only facilitates biometry measurements by minimizing acquisition time and thus reducing motion, but also enables volumetric OCT for comprehensive structural analysis and OCT angiography (OCTA) for visualizing vasculature. The 15.5 mm (~ 11.6 mm in tissue) depth range spans all optical surfaces from the anterior cornea to the posterior lens capsule. The 1310 nm wavelength range enables structural OCT and OCTA deep in the sclera and through the iris. Achieving high speed and long range requires linearizing the VCSEL wavenumber sweep to efficiently utilize analog-to-digital conversion bandwidth. Dual channel recording of the OCT and calibration interferometer fringe signals, as well as sweep to sweep wavenumber compensation, is used to achieve invariant 12.2 µm (~ 9.1 µm in tissue) axial resolution and optimum point spread function throughout the depth range. Dynamic focusing using a tunable liquid lens extends the effective depth of field while preserving the lateral resolution. Improved optical and mechanical design, including parallax “split view” iris cameras and stable, ergonomic patient interface, facilitates accurate instrument positioning, reduces patient motion, and leads to improved imaging data yield and measurement accuracy. We present structural and angiographic OCT images of the anterior eye, demonstrating the unique imaging capabilities using representative scanning protocols which may be relevant to future research and clinical applications.
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Gunzinger JM, Ibrahimi B, Baur J, Wiest MRJ, Piccirelli M, Pangalu A, Straumann D, Nietlispach F, Moarof I, Zweifel SA. Assessment of Retinal Capillary Dropout after Transcatheter Aortic Valve Implantation by Optical Coherence Tomography Angiography. Diagnostics (Basel) 2021; 11:diagnostics11122399. [PMID: 34943635 PMCID: PMC8700652 DOI: 10.3390/diagnostics11122399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 11/24/2022] Open
Abstract
Transcatheter aortic valve implantation (TAVI) is an alternative to open heart surgery in the treatment of symptomatic aortic valve stenosis, which is often the treatment of choice in elderly and frail patients. It carries a risk of embolic complications in the whole cerebral vascular bed, which includes the retinal vasculature. The main objective was the evaluation of retinal emboli visible on optical coherence tomography angiography (OCTA) following TAVI. This is a prospective, single center, observational study enrolling consecutive patients over two years. Patients were assessed pre- and post-TAVI. Twenty-eight patients were included in the final analysis, 82.1% were male, median age was 79.5 (range 52–88), median BCVA was 82.5 letters (range 75–93). Eight patients (28.6%) presented new capillary dropout lesions in their post-TAVI OCTA scans. There was no statistically significant change in BCVA. Quantitative analysis of macular or peripapillary OCTA parameters did not show any statistically significant difference in pre- and post-intervention. In conclusion, capillary dropout lesions could frequently be found in patients after TAVI. Quantitative measurements of macular and peripapillary flow remained stable, possibly indicating effective ocular blood flow regulation within the range of left ventricular ejection fraction in our cohort.
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Affiliation(s)
- Jeanne Martine Gunzinger
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland; (J.B.); (M.R.J.W.); (S.A.Z.)
- Correspondence:
| | - Burbuqe Ibrahimi
- Department of Cardiology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland; (B.I.); (F.N.)
| | - Joel Baur
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland; (J.B.); (M.R.J.W.); (S.A.Z.)
| | - Maximilian Robert Justus Wiest
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland; (J.B.); (M.R.J.W.); (S.A.Z.)
| | - Marco Piccirelli
- Department of Information Technology and Electrical Engineering, ETH Zurich, 8092 Zurich, Switzerland;
| | - Athina Pangalu
- Department of Neuroradiology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland;
| | - Dominik Straumann
- Department of Neurology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland;
| | - Fabian Nietlispach
- Department of Cardiology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland; (B.I.); (F.N.)
- Heartcenter im Park, Hirslanden Clinic Im Park, 8027 Zurich, Switzerland
| | - Igal Moarof
- Department of Cardiology, Kantonsspital Baden, 5404 Baden, Switzerland;
| | - Sandrine Anne Zweifel
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland; (J.B.); (M.R.J.W.); (S.A.Z.)
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6
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Wei S, Kang JU. Stabilizing the phase of swept-source optical coherence tomography by a wrapped Gaussian mixture model. OPTICS LETTERS 2021; 46:2932-2935. [PMID: 34129577 PMCID: PMC9808914 DOI: 10.1364/ol.420898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 05/20/2021] [Indexed: 06/12/2023]
Abstract
The phase of an optical coherence tomography (OCT) signal carries critical information about particle micro-displacements. However, swept-source OCT (SSOCT) suffers from phase instability problems due to trigger jitters from the swept source. In this Letter, a wrapped Gaussian mixture model (WGMM) is proposed to stabilize the phase of SSOCT systems. A closed-form iteration solution of the WGMM is derived using the expectation-maximization algorithm. Necessary approximations are made for real-time graphic processing unit implementation. The performance of the proposed method is demonstrated through ex vivo, in vivo, and flow phantom experiments. The results show the robustness of the method in different application scenarios.
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7
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Liu X, Jiang L, Ke M, Schmetterer L, Barathi VA. Using image data to numerically correct the jitter in polarization depth encoding PS-OCT. OPTICS LETTERS 2021; 46:1692-1695. [PMID: 33793520 DOI: 10.1364/ol.420029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/06/2021] [Indexed: 06/12/2023]
Abstract
In swept source polarization depth encoding polarization sensitive optical coherence tomography (PS-OCT), the laser jitter induces additional noise to the polarization sensitive measurement. In this Letter, we developed a numerical algorithm to correct the jitter phases based on the image data using the Mueller matrix calculus. The algorithm was demonstrated on in vivo retina imaging of a guinea pig with a custom-built PS-OCT system. The performance of the proposed algorithm was almost comparable to the conventional method of using a physical calibration signal. By not requiring a hardware generated calibration signal and k-clock, the proposed algorithm is useful to reduce the complexity and the cost of a polarization depth encoding PS-OCT system.
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8
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Wei X, Hormel TT, Jia Y. Phase-stabilized complex-decorrelation angiography. BIOMEDICAL OPTICS EXPRESS 2021; 12:2419-2431. [PMID: 33996238 PMCID: PMC8086438 DOI: 10.1364/boe.420503] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/20/2021] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
In this study, we developed a novel phase-stabilized complex-decorrelation (PSCD) optical coherence tomography (OCT) angiography (OCTA) method that can generate high quality OCTA images. This method has been validated using three different types of OCT systems and compared with conventional complex- and amplitude-based OCTA algorithms. Our results suggest that in combination with a pre-processing phase stabilization method, the PSCD method is insensitive to bulk motion phase shifts, less dependent on OCT reflectance than conventional complex methods and demonstrates extended dynamic range of flow signal, in contrast to other two methods.
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Affiliation(s)
- Xiang Wei
- Casey Eye Institute, Oregon Health and Science University, Portland, Oregon 97239, USA
- Department of Biomedical Engineer, Oregon Health and Science University, Portland, Oregon 97239, USA
| | - Tristan T. Hormel
- Casey Eye Institute, Oregon Health and Science University, Portland, Oregon 97239, USA
| | - Yali Jia
- Casey Eye Institute, Oregon Health and Science University, Portland, Oregon 97239, USA
- Department of Biomedical Engineer, Oregon Health and Science University, Portland, Oregon 97239, USA
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9
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Zhang J, Nguyen T, Potsaid B, Jayaraman V, Burgner C, Chen S, Li J, Liang K, Cable A, Traverso G, Mashimo H, Fujimoto JG. Multi-MHz MEMS-VCSEL swept-source optical coherence tomography for endoscopic structural and angiographic imaging with miniaturized brushless motor probes. BIOMEDICAL OPTICS EXPRESS 2021; 12:2384-2403. [PMID: 33996236 PMCID: PMC8086463 DOI: 10.1364/boe.420394] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/10/2021] [Accepted: 03/18/2021] [Indexed: 05/02/2023]
Abstract
Swept source optical coherence tomography (SS-OCT) enables volumetric imaging of subsurface structure. However, applications requiring wide fields of view (FOV), rapid imaging, and higher resolutions have been challenging because multi-MHz axial scan (A-scan) rates are needed. We describe a microelectromechanical systems vertical cavity surface-emitting laser (MEMS-VCSEL) SS-OCT technology for A-scan rates of 2.4 and 3.0 MHz. Sweep to sweep calibration and resampling are performed using dual channel acquisition of the OCT signal and a Mach Zehnder interferometer signal, overcoming inherent optical clock limitations and enabling higher performance. We demonstrate ultrahigh speed structural SS-OCT and OCT angiography (OCTA) imaging of the swine gastrointestinal tract using a suite of miniaturized brushless motor probes, including a 3.2 mm diameter micromotor OCT catheter, a 12 mm diameter tethered OCT capsule, and a 12 mm diameter widefield OCTA probe. MEMS-VCSELs promise to enable ultrahigh speed SS-OCT with a scalable, low cost, and manufacturable technology, suitable for a diverse range of imaging applications.
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Affiliation(s)
- Jason Zhang
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- These authors contributed equally to this work
| | - Tan Nguyen
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- These authors contributed equally to this work
| | - Benjamin Potsaid
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Advanced Imaging Group, Thorlabs Inc., Newton, NJ 07860, USA
| | | | | | - Siyu Chen
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jinxi Li
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Kaicheng Liang
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alex Cable
- Advanced Imaging Group, Thorlabs Inc., Newton, NJ 07860, USA
| | - Giovanni Traverso
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Division of Gastroenterology, Massachusetts General Hospital, Boston, MA 02114, USA
- Division of Gastroenterology, Brigham and Women’s Hospital, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Hiroshi Mashimo
- Harvard Medical School, Boston, MA 02115, USA
- Veterans Affairs Boston Healthcare System, Boston, MA 02132, USA
| | - James G. Fujimoto
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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10
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Optical coherence tomography angiography in preclinical neuroimaging. Biomed Eng Lett 2019; 9:311-325. [PMID: 31456891 DOI: 10.1007/s13534-019-00118-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 04/29/2019] [Accepted: 06/27/2019] [Indexed: 01/22/2023] Open
Abstract
Preclinical neuroimaging allows for the assessment of brain anatomy, connectivity, and function in laboratory animals, such as mice and this imaging field has been a rapidly growing aimed at bridging the translation gap between animal and human research. The progress in the animal research could be accelerated by high-resolution in vivo optical imaging technologies. Optical coherence tomography-based angiography (OCTA) estimates the scattering from moving red blood cells, providing the visualization of functional micro-vessel networks within tissue beds in vivo without a need for exogenous contrast agents. Recent advancement of OCTA methods have expanded its application to neuroimaging of small animal models of brain disorders. In this paper, we overview the recent development of OCTA techniques for blood flow imaging and its preclinical applications in neuroimaging. In specific, a summary of preclinical OCTA studies for traumatic brain injury, cerebral stroke, and aging brain on mice is reviewed.
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11
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Ramier A, Tavakol B, Yun SH. Measuring mechanical wave speed, dispersion, and viscoelastic modulus of the cornea using optical coherence elastography. OPTICS EXPRESS 2019; 27:16635-16649. [PMID: 31252887 PMCID: PMC6825608 DOI: 10.1364/oe.27.016635] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/14/2019] [Accepted: 04/16/2019] [Indexed: 05/22/2023]
Abstract
Acoustic wave velocity measurement based on optical coherence tomography (OCT) is a promising approach to assess the mechanical properties of biological tissues and soft materials. While studies to date have demonstrated proof of concept of different ways to excite and detect mechanical waves, the quantitative performance of this modality as mechanical measurement has been underdeveloped. Here, we investigate the frequency dependent measurement of the wave propagation in viscoelastic tissues, using a piezoelectric point-contact probe driven with various waveforms. We found that a frequency range of 2-10 kHz is a good window for corneal elastography, in which the lowest-order flexural waves can be identified in post processing. We tested our system on tissue-simulating phantoms and ex vivo porcine eyes, and demonstrate reproducibility and inter-sample variability. Using the Kelvin-Voigt model of viscoelasticity, we extracted the shear-elastic modulus and viscosity of the cornea and their correlation with the corneal thickness, curvature, and eyeball mass. Our results show that our method can be a quantitative, useful tool for the mechanical analysis of the cornea.
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Affiliation(s)
- Antoine Ramier
- Wellman Center for photomedicine and Harvard Medical School, Massachusetts General Hospital, 50 Blossom St., BAR-8, Boston, MA 02114,
USA
- Harvard-MIT division of Health Sciences and Technology, Cambridge, MA,
USA
| | - Behrouz Tavakol
- Wellman Center for photomedicine and Harvard Medical School, Massachusetts General Hospital, 50 Blossom St., BAR-8, Boston, MA 02114,
USA
| | - Seok-Hyun Yun
- Wellman Center for photomedicine and Harvard Medical School, Massachusetts General Hospital, 50 Blossom St., BAR-8, Boston, MA 02114,
USA
- Harvard-MIT division of Health Sciences and Technology, Cambridge, MA,
USA
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12
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Feroldi F, Willemse J, Davidoiu V, Gräfe MGO, van Iperen DJ, Goorsenberg AWM, Annema JT, Daniels JMA, Bonta PI, de Boer JF. In vivo multifunctional optical coherence tomography at the periphery of the lungs. BIOMEDICAL OPTICS EXPRESS 2019; 10:3070-3091. [PMID: 31259075 PMCID: PMC6583343 DOI: 10.1364/boe.10.003070] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/13/2019] [Accepted: 05/14/2019] [Indexed: 05/04/2023]
Abstract
Remodeling of tissue, such as airway smooth muscle (ASM) and extracellular matrix, is considered a key feature of airways disease. No clinically accepted diagnostic method is currently available to assess airway remodeling or the effect of treatment modalities such as bronchial thermoplasty in asthma, other than invasive airway biopsies. Optical coherence tomography (OCT) generates cross-sectional, near-histological images of airway segments and enables identification and quantification of airway wall layers based on light scattering properties only. In this study, we used a custom motorized OCT probe that combines standard and polarization sensitive OCT (PS-OCT) to visualize birefringent tissue in vivo in the airway wall of a patient with severe asthma in a minimally invasive manner. We used optic axis uniformity (OAxU) to highlight the presence of uniformly arranged fiber-like tissue, helping visualizing the abundance of ASM and connective tissue structures. Attenuation coefficient images of the airways are presented for the first time, showing superior architectural contrast compared to standard OCT images. A novel segmentation algorithm was developed to detect the surface of the endoscope sheath and the surface of the tissue. PS-OCT is an innovative imaging technique that holds promise to assess airway remodeling including ASM and connective tissue in a minimally invasive, real-time manner.
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Affiliation(s)
- Fabio Feroldi
- LaserLaB Amsterdam and Department of Physics and Astronomy, VU University Amsterdam, de Boelelaan 1081, 1081HV, Amsterdam, the Netherlands
| | - Joy Willemse
- LaserLaB Amsterdam and Department of Physics and Astronomy, VU University Amsterdam, de Boelelaan 1081, 1081HV, Amsterdam, the Netherlands
- These authors contributed equally
| | - Valentina Davidoiu
- LaserLaB Amsterdam and Department of Physics and Astronomy, VU University Amsterdam, de Boelelaan 1081, 1081HV, Amsterdam, the Netherlands
- These authors contributed equally
| | - Maximilian G. O. Gräfe
- LaserLaB Amsterdam and Department of Physics and Astronomy, VU University Amsterdam, de Boelelaan 1081, 1081HV, Amsterdam, the Netherlands
| | - Dirck J. van Iperen
- LaserLaB Amsterdam and Department of Physics and Astronomy, VU University Amsterdam, de Boelelaan 1081, 1081HV, Amsterdam, the Netherlands
| | - Annika W. M. Goorsenberg
- Amsterdam University Medical Center, Department of Pulmonology, University of Amsterdam, Amsterdam, the Netherlands
| | - Jouke T. Annema
- Amsterdam University Medical Center, Department of Pulmonology, University of Amsterdam, Amsterdam, the Netherlands
| | - Johannes M. A. Daniels
- Amsterdam University Medical Center, Department of Pulmonology, VUmc Location, Amsterdam, the Netherlands
| | - Peter I. Bonta
- Amsterdam University Medical Center, Department of Pulmonology, University of Amsterdam, Amsterdam, the Netherlands
| | - Johannes F. de Boer
- LaserLaB Amsterdam and Department of Physics and Astronomy, VU University Amsterdam, de Boelelaan 1081, 1081HV, Amsterdam, the Netherlands
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13
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Yamanari M, Uematsu S, Ishihara K, Ikuno Y. Parallel detection of Jones-matrix elements in polarization-sensitive optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2019; 10:2318-2336. [PMID: 31149375 PMCID: PMC6524579 DOI: 10.1364/boe.10.002318] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/16/2019] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
The polarization properties of a sample can be characterized using a Jones matrix. To measure the Jones matrix without assumptions of the sample, two different incident states of polarization are usually used. This requirement often causes certain drawbacks in polarization-sensitive optical coherence tomography (PS-OCT), e.g., a decrease in the effective A-scan rate or axial depth range, if a multiplexing scheme is used. Because both the A-scan rate and axial depth range are important for clinical applications, including the imaging of an anterior eye segment, a new PS-OCT method that does not have these drawbacks is desired. Here, we present a parallel-detection approach that maintains the same A-scan rate and axial measurement range as conventional OCT. The interferometer consists of fiber-optic components, most of which are polarization-maintaining components with fast-axis blocking free from polarization management. When a parallel detection is implemented using swept-source OCT (SS-OCT), synchronization between the A-scans and synchronization between the detection channels have critical effects on the Jones-matrix measurement. Because it is difficult to achieve perfect synchronization using only hardware, we developed a solution using a numerical correction with signals from a static mirror. Using the developed system, we demonstrate the imaging of an anterior eye segment from the cornea to the back surface of the crystalline lens.
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Affiliation(s)
- Masahiro Yamanari
- Engineering Department, Tomey Corporation, 2-11-33 Noritakeshinmachi, Nishiku, Nagoya, Aichi, 451-0051, Japan
| | - Sato Uematsu
- Department of Ophthalmology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Kenji Ishihara
- Engineering Department, Tomey Corporation, 2-11-33 Noritakeshinmachi, Nishiku, Nagoya, Aichi, 451-0051, Japan
| | - Yasushi Ikuno
- Ikuno Eye Center, 2-9-10 3F Juso-Higashi, Yodogawaku, Osaka, Osaka, 532-0023, Japan
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14
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Migacz JV, Gorczynska I, Azimipour M, Jonnal R, Zawadzki RJ, Werner JS. Megahertz-rate optical coherence tomography angiography improves the contrast of the choriocapillaris and choroid in human retinal imaging. BIOMEDICAL OPTICS EXPRESS 2019; 10:50-65. [PMID: 30775082 PMCID: PMC6363198 DOI: 10.1364/boe.10.000050] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/25/2018] [Accepted: 11/27/2018] [Indexed: 05/03/2023]
Abstract
Angiographic imaging of the human eye with optical coherence tomography (OCT) is becoming an increasingly important tool in the scientific investigation and clinical management of several blinding diseases, including age-related macular degeneration and diabetic retinopathy. We have observed that OCT angiography (OCTA) of the human choriocapillaris and choroid with a 1.64 MHz A-scan rate swept-source laser yields higher contrast images as compared to a slower rate system operating at 100 kHz. This result is unexpected because signal sensitivity is reduced when acquisition rates are increased, and the incident illumination power is kept constant. The contrast of angiography images generated by acquiring multiple sequential frames and calculating the variation caused by blood flow, however, appears to be improved significantly when lower-contrast images are taken more rapidly. To demonstrate that the acquisition rate plays a role in the quality improvement, we have imaged five healthy subjects with a narrow field of view (1.2 mm) OCTA imaging system using two separate swept-source lasers of different A-line rates and compared the results quantitatively using the radially-averaged power spectrum. The average improvement in the contrast is 23.0% (+/-7.6%). Although the underlying cause of this enhancement is not explicitly determined here, we speculate that the higher-speed system suppresses the noise contribution from eye motion in subjects and operates with an inter-scan time that better discriminates the flow velocities present in the choroid and choriocapillaris. Our result informs OCT system developers on the merits of ultrahigh-speed acquisition in functional imaging applications.
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Affiliation(s)
- Justin V. Migacz
- Vison Science and Advanced Retinal Imaging Laboratory, Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
| | - Iwona Gorczynska
- Vison Science and Advanced Retinal Imaging Laboratory, Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
- Institute of Physics, Faculty of Physics, Astronomy, and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland
| | - Mehdi Azimipour
- Vison Science and Advanced Retinal Imaging Laboratory, Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
| | - Ravi Jonnal
- Vison Science and Advanced Retinal Imaging Laboratory, Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
| | - Robert J. Zawadzki
- Vison Science and Advanced Retinal Imaging Laboratory, Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
| | - John S. Werner
- Vison Science and Advanced Retinal Imaging Laboratory, Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
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15
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Wells WA, Thrall M, Sorokina A, Fine J, Krishnamurthy S, Haroon A, Rao B, Shevchuk MM, Wolfsen HC, Tearney GJ, Hariri LP. In Vivo and Ex Vivo Microscopy: Moving Toward the Integration of Optical Imaging Technologies Into Pathology Practice. Arch Pathol Lab Med 2018; 143:288-298. [PMID: 30525931 DOI: 10.5858/arpa.2018-0298-ra] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The traditional surgical pathology assessment requires tissue to be removed from the patient, then processed, sectioned, stained, and interpreted by a pathologist using a light microscope. Today, an array of alternate optical imaging technologies allow tissue to be viewed at high resolution, in real time, without the need for processing, fixation, freezing, or staining. Optical imaging can be done in living patients without tissue removal, termed in vivo microscopy, or also in freshly excised tissue, termed ex vivo microscopy. Both in vivo and ex vivo microscopy have tremendous potential for clinical impact in a wide variety of applications. However, in order for these technologies to enter mainstream clinical care, an expert will be required to assess and interpret the imaging data. The optical images generated from these imaging techniques are often similar to the light microscopic images that pathologists already have expertise in interpreting. Other clinical specialists do not have this same expertise in microscopy, therefore, pathologists are a logical choice to step into the developing role of microscopic imaging expert. Here, we review the emerging technologies of in vivo and ex vivo microscopy in terms of the technical aspects and potential clinical applications. We also discuss why pathologists are essential to the successful clinical adoption of such technologies and the educational resources available to help them step into this emerging role.
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Affiliation(s)
- Wendy A Wells
- From the Department of Pathology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (Dr Wells); the Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas (Dr Thrall); the Department of Pathology, University of Illinois at Chicago, Chicago (Dr Sorokina); the Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (Dr Fine); the Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston (Dr Krishnamurthy); the Department of Dermatology, Rutgers-Robert Wood Johnson Medical School, Somerset, New Jersey (Drs Haroon and Rao); the Department of Pathology, Weill Cornell Medical College, New York, New York (Dr Shevchuk); the Division of Gastroenterology & Hepatology, Mayo Clinic, Jacksonville, Florida (Dr Wolfsen); and the Wellman Center for Photomedicine (Dr Tearney) and the Department of Pathology (Drs Tearney and Hariri), Massachusetts General Hospital, Harvard Medical School, Boston
| | - Michael Thrall
- From the Department of Pathology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (Dr Wells); the Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas (Dr Thrall); the Department of Pathology, University of Illinois at Chicago, Chicago (Dr Sorokina); the Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (Dr Fine); the Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston (Dr Krishnamurthy); the Department of Dermatology, Rutgers-Robert Wood Johnson Medical School, Somerset, New Jersey (Drs Haroon and Rao); the Department of Pathology, Weill Cornell Medical College, New York, New York (Dr Shevchuk); the Division of Gastroenterology & Hepatology, Mayo Clinic, Jacksonville, Florida (Dr Wolfsen); and the Wellman Center for Photomedicine (Dr Tearney) and the Department of Pathology (Drs Tearney and Hariri), Massachusetts General Hospital, Harvard Medical School, Boston
| | - Anastasia Sorokina
- From the Department of Pathology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (Dr Wells); the Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas (Dr Thrall); the Department of Pathology, University of Illinois at Chicago, Chicago (Dr Sorokina); the Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (Dr Fine); the Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston (Dr Krishnamurthy); the Department of Dermatology, Rutgers-Robert Wood Johnson Medical School, Somerset, New Jersey (Drs Haroon and Rao); the Department of Pathology, Weill Cornell Medical College, New York, New York (Dr Shevchuk); the Division of Gastroenterology & Hepatology, Mayo Clinic, Jacksonville, Florida (Dr Wolfsen); and the Wellman Center for Photomedicine (Dr Tearney) and the Department of Pathology (Drs Tearney and Hariri), Massachusetts General Hospital, Harvard Medical School, Boston
| | - Jeffrey Fine
- From the Department of Pathology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (Dr Wells); the Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas (Dr Thrall); the Department of Pathology, University of Illinois at Chicago, Chicago (Dr Sorokina); the Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (Dr Fine); the Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston (Dr Krishnamurthy); the Department of Dermatology, Rutgers-Robert Wood Johnson Medical School, Somerset, New Jersey (Drs Haroon and Rao); the Department of Pathology, Weill Cornell Medical College, New York, New York (Dr Shevchuk); the Division of Gastroenterology & Hepatology, Mayo Clinic, Jacksonville, Florida (Dr Wolfsen); and the Wellman Center for Photomedicine (Dr Tearney) and the Department of Pathology (Drs Tearney and Hariri), Massachusetts General Hospital, Harvard Medical School, Boston
| | - Savitri Krishnamurthy
- From the Department of Pathology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (Dr Wells); the Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas (Dr Thrall); the Department of Pathology, University of Illinois at Chicago, Chicago (Dr Sorokina); the Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (Dr Fine); the Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston (Dr Krishnamurthy); the Department of Dermatology, Rutgers-Robert Wood Johnson Medical School, Somerset, New Jersey (Drs Haroon and Rao); the Department of Pathology, Weill Cornell Medical College, New York, New York (Dr Shevchuk); the Division of Gastroenterology & Hepatology, Mayo Clinic, Jacksonville, Florida (Dr Wolfsen); and the Wellman Center for Photomedicine (Dr Tearney) and the Department of Pathology (Drs Tearney and Hariri), Massachusetts General Hospital, Harvard Medical School, Boston
| | - Attiya Haroon
- From the Department of Pathology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (Dr Wells); the Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas (Dr Thrall); the Department of Pathology, University of Illinois at Chicago, Chicago (Dr Sorokina); the Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (Dr Fine); the Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston (Dr Krishnamurthy); the Department of Dermatology, Rutgers-Robert Wood Johnson Medical School, Somerset, New Jersey (Drs Haroon and Rao); the Department of Pathology, Weill Cornell Medical College, New York, New York (Dr Shevchuk); the Division of Gastroenterology & Hepatology, Mayo Clinic, Jacksonville, Florida (Dr Wolfsen); and the Wellman Center for Photomedicine (Dr Tearney) and the Department of Pathology (Drs Tearney and Hariri), Massachusetts General Hospital, Harvard Medical School, Boston
| | - Babar Rao
- From the Department of Pathology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (Dr Wells); the Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas (Dr Thrall); the Department of Pathology, University of Illinois at Chicago, Chicago (Dr Sorokina); the Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (Dr Fine); the Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston (Dr Krishnamurthy); the Department of Dermatology, Rutgers-Robert Wood Johnson Medical School, Somerset, New Jersey (Drs Haroon and Rao); the Department of Pathology, Weill Cornell Medical College, New York, New York (Dr Shevchuk); the Division of Gastroenterology & Hepatology, Mayo Clinic, Jacksonville, Florida (Dr Wolfsen); and the Wellman Center for Photomedicine (Dr Tearney) and the Department of Pathology (Drs Tearney and Hariri), Massachusetts General Hospital, Harvard Medical School, Boston
| | - Maria M Shevchuk
- From the Department of Pathology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (Dr Wells); the Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas (Dr Thrall); the Department of Pathology, University of Illinois at Chicago, Chicago (Dr Sorokina); the Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (Dr Fine); the Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston (Dr Krishnamurthy); the Department of Dermatology, Rutgers-Robert Wood Johnson Medical School, Somerset, New Jersey (Drs Haroon and Rao); the Department of Pathology, Weill Cornell Medical College, New York, New York (Dr Shevchuk); the Division of Gastroenterology & Hepatology, Mayo Clinic, Jacksonville, Florida (Dr Wolfsen); and the Wellman Center for Photomedicine (Dr Tearney) and the Department of Pathology (Drs Tearney and Hariri), Massachusetts General Hospital, Harvard Medical School, Boston
| | - Herbert C Wolfsen
- From the Department of Pathology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (Dr Wells); the Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas (Dr Thrall); the Department of Pathology, University of Illinois at Chicago, Chicago (Dr Sorokina); the Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (Dr Fine); the Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston (Dr Krishnamurthy); the Department of Dermatology, Rutgers-Robert Wood Johnson Medical School, Somerset, New Jersey (Drs Haroon and Rao); the Department of Pathology, Weill Cornell Medical College, New York, New York (Dr Shevchuk); the Division of Gastroenterology & Hepatology, Mayo Clinic, Jacksonville, Florida (Dr Wolfsen); and the Wellman Center for Photomedicine (Dr Tearney) and the Department of Pathology (Drs Tearney and Hariri), Massachusetts General Hospital, Harvard Medical School, Boston
| | - Guillermo J Tearney
- From the Department of Pathology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (Dr Wells); the Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas (Dr Thrall); the Department of Pathology, University of Illinois at Chicago, Chicago (Dr Sorokina); the Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (Dr Fine); the Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston (Dr Krishnamurthy); the Department of Dermatology, Rutgers-Robert Wood Johnson Medical School, Somerset, New Jersey (Drs Haroon and Rao); the Department of Pathology, Weill Cornell Medical College, New York, New York (Dr Shevchuk); the Division of Gastroenterology & Hepatology, Mayo Clinic, Jacksonville, Florida (Dr Wolfsen); and the Wellman Center for Photomedicine (Dr Tearney) and the Department of Pathology (Drs Tearney and Hariri), Massachusetts General Hospital, Harvard Medical School, Boston
| | - Lida P Hariri
- From the Department of Pathology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (Dr Wells); the Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas (Dr Thrall); the Department of Pathology, University of Illinois at Chicago, Chicago (Dr Sorokina); the Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (Dr Fine); the Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston (Dr Krishnamurthy); the Department of Dermatology, Rutgers-Robert Wood Johnson Medical School, Somerset, New Jersey (Drs Haroon and Rao); the Department of Pathology, Weill Cornell Medical College, New York, New York (Dr Shevchuk); the Division of Gastroenterology & Hepatology, Mayo Clinic, Jacksonville, Florida (Dr Wolfsen); and the Wellman Center for Photomedicine (Dr Tearney) and the Department of Pathology (Drs Tearney and Hariri), Massachusetts General Hospital, Harvard Medical School, Boston
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16
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Feroldi F, Verlaan M, Knaus H, Davidoiu V, Vugts DJ, van Dongen GAMS, Molthoff CFM, de Boer JF. High resolution combined molecular and structural optical imaging of colorectal cancer in a xenograft mouse model. BIOMEDICAL OPTICS EXPRESS 2018; 9:6186-6204. [PMID: 31065422 PMCID: PMC6491025 DOI: 10.1364/boe.9.006186] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/01/2018] [Accepted: 11/06/2018] [Indexed: 05/08/2023]
Abstract
With the emergence of immunotherapies for cancer treatment, there is a rising clinical need to visualize the tumor microenvironment (TME) non-invasively in detail, which could be crucial to predict the efficacy of therapy. Nuclear imaging techniques enable whole-body imaging but lack the required spatial resolution. Conversely, near-infrared immunofluorescence (immuno-NIRF) is able to reveal tumor cells and/or other cell subsets in the TME by targeting the expression of a specific membrane receptor with fluorescently labeled monoclonal antibodies (mAb). Optical coherence tomography (OCT) provides three-dimensional morphological imaging of tissues without exogenous contrast agents. The combination of the two allows molecular and structural contrast at a resolution of ~15 µm, allowing for the specific location of a cell-type target with immuno-NIRF as well as revealing the three-dimensional architectural context with OCT. For the first time, combined immuno-NIRF and OCT of a tumor is demonstrated in situ in a xenograft mouse model of human colorectal cancer, targeted by a clinically-safe fluorescent mAb, revealing unprecedented details of the TME. A handheld scanner for ex vivo examination and an endoscope designed for imaging bronchioles in vivo are presented. This technique promises to complement nuclear imaging for diagnosing cancer invasiveness, precisely determining tumor margins, and studying the biodistribution of newly developed antibodies in high detail.
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Affiliation(s)
- Fabio Feroldi
- Department of Physics and Astronomy, LaserLaB Amsterdam, VU University Amsterdam, de Boelelaan 1081, 1081HV, Amsterdam, The Netherlands
| | - Mariska Verlaan
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Radiology & Nuclear Medicine, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Helene Knaus
- Department of Physics and Astronomy, LaserLaB Amsterdam, VU University Amsterdam, de Boelelaan 1081, 1081HV, Amsterdam, The Netherlands
| | - Valentina Davidoiu
- Department of Physics and Astronomy, LaserLaB Amsterdam, VU University Amsterdam, de Boelelaan 1081, 1081HV, Amsterdam, The Netherlands
| | - Danielle J. Vugts
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Radiology & Nuclear Medicine, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Guus A. M. S. van Dongen
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Radiology & Nuclear Medicine, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Carla F. M. Molthoff
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Radiology & Nuclear Medicine, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Johannes F. de Boer
- Department of Physics and Astronomy, LaserLaB Amsterdam, VU University Amsterdam, de Boelelaan 1081, 1081HV, Amsterdam, The Netherlands
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17
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Moon S, Chen Z. Phase-stability optimization of swept-source optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2018; 9:5280-5295. [PMID: 30460128 PMCID: PMC6238911 DOI: 10.1364/boe.9.005280] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/21/2018] [Accepted: 09/25/2018] [Indexed: 05/18/2023]
Abstract
Phase-resolved imaging of swept-source optical coherence tomography (SS-OCT) is subject to phase measurement instabilities involved with the sweep variation of a frequency-swept source. In general, optically generated timing references are utilized to track the variations imposed on OCT signals. But they might not be accurately synchronized due to relative time delays. In this research, we investigated the impact of the signal delays on the timing instabilities and the consequent deviations of the measured phases. We considered two types of timing signals utilized in a popular digitizer operation mode: a sweep trigger from a fiber Bragg grating (FBG) that initiates a series of signal sampling actions clocked by an auxiliary Mach-Zehnder interferometer (MZI) signal. We found that significant instabilities were brought by the relative delays through incoherent timing corrections and timing collisions between the timing references. The best-to-worst ratio of the measured phase errors was higher than 200 while only the signal delays varied. Noise-limited phase stability was achieved with a wide dynamic range of OCT signals above 50 dB in optimized delays. This demonstrated that delay optimization is very effective in phase stabilization of SS-OCT.
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Affiliation(s)
- Sucbei Moon
- Beckman Laser Institute, University of California, Irvine, Irvine, CA 92617, USA
- Department of Physics, Kookmin University, Seoul 02707, South Korea
| | - Zhongping Chen
- Beckman Laser Institute, University of California, Irvine, Irvine, CA 92617, USA
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA
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18
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Ramier A, Cheng JT, Ravicz ME, Rosowski JJ, Yun SH. Mapping the phase and amplitude of ossicular chain motion using sound-synchronous optical coherence vibrography. BIOMEDICAL OPTICS EXPRESS 2018; 9:5489-5502. [PMID: 30460142 PMCID: PMC6238908 DOI: 10.1364/boe.9.005489] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 09/10/2018] [Accepted: 09/12/2018] [Indexed: 05/21/2023]
Abstract
The sound-driven vibration of the tympanic membrane and ossicular chain of middle-ear bones is fundamental to hearing. Here we show that optical coherence tomography in phase synchrony with a sound stimulus is well suited for volumetric, vibrational imaging of the ossicles and tympanic membrane. This imaging tool - OCT vibrography - provides intuitive motion pictures of the ossicular chain and how they vary with frequency. Using the chinchilla ear as a model, we investigated the vibrational snapshots and phase delays of the manubrium, incus, and stapes over 100 Hz to 15 kHz. The vibrography images reveal a previously undescribed mode of motion of the chinchilla ossicles at high frequencies.
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Affiliation(s)
- Antoine Ramier
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA
| | - Jeffrey Tao Cheng
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Michael E. Ravicz
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - John J. Rosowski
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Seok-Hyun Yun
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA
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19
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de Jong JH, Braaf B, Amarakoon S, Gräfe M, Yzer S, Vermeer KA, Missotten T, de Boer JF, van Velthoven MEJ. Treatment Effects in Retinal Angiomatous Proliferation Imaged with OCT Angiography. Ophthalmologica 2018; 241:143-153. [PMID: 30227415 DOI: 10.1159/000491798] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 07/04/2018] [Indexed: 11/19/2022]
Abstract
PURPOSE This prospective case series is aimed at exploring optical coherence tomographic angiography (OCT-A) as a treatment monitoring tool in patients treated for retinal angiomatous proliferation (RAP). METHODS Twelve treatment-naïve RAP patients were included, with a median age of 79 years (range 65-90). Patients were imaged with an experimental 1,040-nm swept-source phase-resolved OCT-A instrument before and after treatment. Treatment consisted of either intravitreal bevacizumab or triamcinolone injections with or without photodynamic therapy (PDT). Abnormal blood flow after treatment was graded as increased, unchanged, decreased, or resolved. RESULTS OCT-A images before and after treatment could be obtained in 9 patients. The median follow-up period was 10 weeks (range 5-19). After various treatments, the RAP lesion resolved in 7 patients, in 1 patient the OCT-A depicted decreased flow in the lesion, and 1 patient showed unchanged abnormal blood flow. Monotherapy with intravitreal bevacizumab injections resolved RAP in 1 out of 2 patients. Combined therapy of bevacizumab with PDT resolved RAP in 6 out of 7 patients. CONCLUSIONS OCT-A visualized resolution of abnormal blood flow in 7 out of 9 RAP patients after various short-term treatment sequences. OCT-A may become an important noninvasive monitoring tool for optimizing treatment strategies in RAP patients.
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Affiliation(s)
- Jan H de Jong
- Rotterdam Ophthalmic Institute, Rotterdam, The Netherlands.,Rotterdam Eye Hospital, Rotterdam, The Netherlands
| | - Boy Braaf
- Institute for Lasers, Life and Biophotonics Amsterdam, Department of Physics and Astronomy, VU University, Amsterdam, The Netherlands
| | - Sankha Amarakoon
- Rotterdam Ophthalmic Institute, Rotterdam, The Netherlands.,Rotterdam Eye Hospital, Rotterdam, The Netherlands
| | - Maximilian Gräfe
- Institute for Lasers, Life and Biophotonics Amsterdam, Department of Physics and Astronomy, VU University, Amsterdam, The Netherlands
| | - Suzanne Yzer
- Rotterdam Ophthalmic Institute, Rotterdam, The Netherlands.,Rotterdam Eye Hospital, Rotterdam, The Netherlands
| | | | - Tom Missotten
- Rotterdam Ophthalmic Institute, Rotterdam, The Netherlands.,Rotterdam Eye Hospital, Rotterdam, The Netherlands
| | - Johannes F de Boer
- Rotterdam Ophthalmic Institute, Rotterdam, The Netherlands.,Institute for Lasers, Life and Biophotonics Amsterdam, Department of Physics and Astronomy, VU University, Amsterdam, The Netherlands
| | - Mirjam E J van Velthoven
- Rotterdam Ophthalmic Institute, Rotterdam, The Netherlands, .,Rotterdam Eye Hospital, Rotterdam, The Netherlands,
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20
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Gao W. Quantitative depth-resolved microcirculation imaging with optical coherence tomography angiography (Part ΙΙ): Microvascular network imaging. Microcirculation 2018; 25:e12376. [DOI: 10.1111/micc.12376] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 04/11/2017] [Indexed: 11/28/2022]
Affiliation(s)
- Wanrong Gao
- Department of Optical Engineering; Nanjing University of Science and Technology; Nanjing Jiangsu China
- MIIT Key Laboratory of Advanced Solid Laser; Nanjing University of Science and Technology; Nanjing Jiangsu China
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21
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Lal C, Subhash HM, Alexandrov S, Leahy MJ. Feasibility of correlation mapping optical coherence tomography angiographic technique using a 200 kHz vertical-cavity surface-emitting laser source for in vivo microcirculation imaging applications. APPLIED OPTICS 2018; 57:E224-E231. [PMID: 30117906 DOI: 10.1364/ao.57.00e224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/04/2018] [Indexed: 05/19/2023]
Abstract
Optical coherence tomography (OCT) angiography is a well-established in vivo imaging technique to assess the overall vascular morphology of tissues and is an emerging field of research for the assessment of blood flow dynamics and functional parameters such as oxygen saturation. In this study, we present a modified scanning-based correlation mapping OCT using a 200 kHz high-speed swept-source OCT system operating at 1300 nm and demonstrate its wide field-imaging capability in ocular angiographic studies.
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22
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Tozburun S, Blatter C, Siddiqui M, Meijer EFJ, Vakoc BJ. Phase-stable Doppler OCT at 19 MHz using a stretched-pulse mode-locked laser. BIOMEDICAL OPTICS EXPRESS 2018; 9:952-961. [PMID: 29541496 PMCID: PMC5846541 DOI: 10.1364/boe.9.000952] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 12/13/2017] [Accepted: 12/13/2017] [Indexed: 05/18/2023]
Abstract
We present a swept-wavelength optical coherence tomography (OCT) system with a 19 MHz laser source and electronic phase-locking of the source, acquisition clock, and beam scanning mirrors. The laser is based on stretched-pulse active mode-locking using an electro-optic modulator. Beam scanning in the fast axis uses a resonant micro-electromechanical systems (MEMS) -based mirror at ~23.8 kHz. Acquisition is performed at 1.78 Gigasamples per second using an external fixed clock. Phase sensitive imaging without need for k-clocking, A-line triggers, or phase-calibration methods is demonstrated. The system was used to demonstrate inter-frame and inter-volume Doppler imaging in the mouse ear and brain at 4D acquisition rates of 1, 30, 60 and 100 volumes/sec (V-scans/s). Angiography based on inter-frame and inter-volume methods are presented. The platform offers extremely fast and phase-stable measurements that can be used in preclinical angiographic and Doppler investigations of perfusion dynamics.
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Affiliation(s)
- Serhat Tozburun
- Harvard Medical School, Boston, Massachusetts 02115, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
- Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, 35340 Balcova, Izmir, Turkey
| | - Cedric Blatter
- Harvard Medical School, Boston, Massachusetts 02115, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
| | - Meena Siddiqui
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
| | - Eelco F. J. Meijer
- Harvard Medical School, Boston, Massachusetts 02115, USA
- Edwin L. Steele Laboratory for Tumor Biology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
| | - Benjamin J. Vakoc
- Harvard Medical School, Boston, Massachusetts 02115, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
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23
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Abstract
Rapid, accurate, and nondestructive mapping of material properties is of great interest in many fields, with applications ranging from detection of defects or other subsurface features in semiconductors to estimating temperature rise in various tissue layers during laser therapy. We demonstrate the speed and precision of two interferometric techniques, quantitative phase imaging and phase-resolved optical coherence tomography, in recording optical phase changes induced by energy deposition in various materials. Such phase perturbations can be used to infer sample properties, ranging from absorption and temperature maps to distribution of electric field or resistivity. We derive the theoretical sensitivity limits of such techniques and demonstrate their applicability to the mapping of absorption coefficients, temperature, and electric fields in synthetic and biological samples. Optical phase changes induced by transient perturbations provide a sensitive measure of material properties. We demonstrate the high sensitivity and speed of such methods, using two interferometric techniques: quantitative phase imaging (QPI) in transmission and phase-resolved optical coherence tomography (OCT) in reflection. Shot-noise–limited QPI can resolve energy deposition of about 3.4 mJ/cm2 in a single pulse, which corresponds to 0.8 °C temperature rise in a single cell. OCT can detect deposition of 24 mJ/cm2 energy between two scattering interfaces producing signals with about 30-dB signal-to-noise ratio (SNR), and 4.7 mJ/cm2 when SNR is 45 dB. Both techniques can image thermal changes within the thermal confinement time, which enables accurate single-shot mapping of absorption coefficients even in highly scattering samples, as well as electrical conductivity and many other material properties in biological samples at cellular scale. Integration of the phase changes along the beam path helps increase sensitivity, and the signal relaxation time reveals the size of hidden objects. These methods may enable multiple applications, ranging from temperature-controlled retinal laser therapy or gene expression to mapping electric current density and characterization of semiconductor devices with rapid pump–probe measurements.
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24
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Braaf B, Donner S, Nam AS, Bouma BE, Vakoc BJ. Complex differential variance angiography with noise-bias correction for optical coherence tomography of the retina. BIOMEDICAL OPTICS EXPRESS 2018; 9:486-506. [PMID: 29552388 PMCID: PMC5854053 DOI: 10.1364/boe.9.000486] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/03/2018] [Accepted: 01/03/2018] [Indexed: 05/05/2023]
Abstract
Complex differential variance (CDV) provides phase-sensitive angiographic imaging for optical coherence tomography (OCT) with immunity to phase-instabilities of the imaging system and small-scale axial bulk motion. However, like all angiographic methods, measurement noise can result in erroneous indications of blood flow that confuse the interpretation of angiographic images. In this paper, a modified CDV algorithm that corrects for this noise-bias is presented. This is achieved by normalizing the CDV signal by analytically derived upper and lower limits. The noise-bias corrected CDV algorithm was implemented into an experimental 1 μm wavelength OCT system for retinal imaging that used an eye tracking scanner laser ophthalmoscope at 815 nm for compensation of lateral eye motions. The noise-bias correction improved the CDV imaging of the blood flow in tissue layers with a low signal-to-noise ratio and suppressed false indications of blood flow outside the tissue. In addition, the CDV signal normalization suppressed noise induced by galvanometer scanning errors and small-scale lateral motion. High quality cross-section and motion-corrected en face angiograms of the retina and choroid are presented.
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Affiliation(s)
- Boy Braaf
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, Massachusetts 02114, USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Sabine Donner
- Heidelberg Engineering GmbH, Max-Jarecki-Straße 8, 69115 Heidelberg, Germany
| | - Ahhyun S. Nam
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, Massachusetts 02114, USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Brett E. Bouma
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, Massachusetts 02114, USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, USA
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
| | - Benjamin J. Vakoc
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, Massachusetts 02114, USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, USA
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
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25
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Xu J, Song S, Li Y, Wang RK. Complex-based OCT angiography algorithm recovers microvascular information better than amplitude- or phase-based algorithms in phase-stable systems. Phys Med Biol 2017; 63:015023. [PMID: 29049034 DOI: 10.1088/1361-6560/aa94bc] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Optical coherence tomography angiography (OCTA) is increasingly becoming a popular inspection tool for biomedical imaging applications. By exploring the amplitude, phase and complex information available in OCT signals, numerous algorithms have been proposed that contrast functional vessel networks within microcirculatory tissue beds. However, it is not clear which algorithm delivers optimal imaging performance. Here, we investigate systematically how amplitude and phase information have an impact on the OCTA imaging performance, to establish the relationship of amplitude and phase stability with OCT signal-to-noise ratio (SNR), time interval and particle dynamics. With either repeated A-scan or repeated B-scan imaging protocols, the amplitude noise increases with the increase of OCT SNR; however, the phase noise does the opposite, i.e. it increases with the decrease of OCT SNR. Coupled with experimental measurements, we utilize a simple Monte Carlo (MC) model to simulate the performance of amplitude-, phase- and complex-based algorithms for OCTA imaging, the results of which suggest that complex-based algorithms deliver the best performance when the phase noise is < ~40 mrad. We also conduct a series of in vivo vascular imaging in animal models and human retina to verify the findings from the MC model through assessing the OCTA performance metrics of vessel connectivity, image SNR and contrast-to-noise ratio. We show that for all the metrics assessed, the complex-based algorithm delivers better performance than either the amplitude- or phase-based algorithms for both the repeated A-scan and the B-scan imaging protocols, which agrees well with the conclusion drawn from the MC simulations.
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Affiliation(s)
- Jingjiang Xu
- Department of Bioengineering, University of Washington, Seattle, WA 98195, United States of America
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26
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Chu Z, Chen CL, Zhang Q, Pepple K, Durbin M, Gregori G, Wang RK. Complex signal-based optical coherence tomography angiography enables in vivo visualization of choriocapillaris in human choroid. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-10. [PMID: 29178697 PMCID: PMC5745879 DOI: 10.1117/1.jbo.22.12.121705] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 11/08/2017] [Indexed: 05/15/2023]
Abstract
The choriocapillaris (CC) plays an essential role in maintaining the normal functions of the human eye. There is increasing interest in the community to develop an imaging technique for visualizing the CC, yet this remains underexplored due to technical limitations. We propose an approach for the visualization of the CC in humans via a complex signal-based optical microangiography (OMAG) algorithm, based on commercially available spectral domain optical coherence tomography (SD-OCT). We show that the complex signal-based OMAG was superior to both the phase and amplitude signal-based approaches in detailing the vascular lobules previously seen with histological analysis. With this improved ability to visualize the lobular vascular networks, it is possible to identify the feeding arterioles and draining venules around the lobules, which is important in understanding the role of the CC in the pathogenesis of ocular diseases. With built-in FastTrac™ and montage scanning capabilities, we also demonstrate wide-field SD-OCT angiograms of the CC with a field of view at 9×11 mm2.
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Affiliation(s)
- Zhongdi Chu
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
| | - Chieh-Li Chen
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
| | - Qinqin Zhang
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
| | - Kathryn Pepple
- University of Washington, Department of Ophthalmology, Seattle, Washington, United States
| | - Mary Durbin
- Carl Zeiss Meditec, Inc., Advanced Development, Dublin, California, United States
| | - Giovanni Gregori
- University of Miami Miller School of Medicine, Bascom Palmer Eye Institute, Department of Ophthalmology, Miami, Florida, United States
| | - Ruikang K. Wang
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
- University of Washington, Department of Ophthalmology, Seattle, Washington, United States
- Address all correspondence to: Ruikang K. Wang, E-mail:
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27
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Song S, Xu J, Men S, Shen TT, Wang RK. Robust numerical phase stabilization for long-range swept-source optical coherence tomography. JOURNAL OF BIOPHOTONICS 2017; 10:1398-1410. [PMID: 28485132 PMCID: PMC5831409 DOI: 10.1002/jbio.201700034] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 03/28/2017] [Accepted: 04/03/2017] [Indexed: 05/03/2023]
Abstract
A novel phase stabilization technique is demonstrated with significant improvement in the phase stability of a micro-electromechanical (MEMS) vertical cavity surface-emitting laser (VCSEL) based swept-source optical coherence tomography (SS-OCT) system. Without any requirements of hardware modifications, the new fully numerical phase stabilization technique features high tolerance to acquisition jitter, and significantly reduced budget in computational effort. We demonstrate that when measured with biological tissue, this technique enables a phase sensitivity of 89 mrad in highly scattering tissue, with image ranging distance of up to 12.5 mm at A-line scan rate of 100.3 kHz. We further compare the performances delivered by the phase-stabilization approach with conventional numerical approach for accuracy and computational efficiency. Imaging result of complex signal-based optical coherence tomography angiography (OCTA) and Doppler OCTA indicate that the proposed phase stabilization technique is robust, and efficient in improving the image contrast-to-noise ratio and extending OCTA depth range. The proposed technique can be universally applied to improve phase-stability in generic SS-OCT with different scale of scan rates without a need for special treatment.
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Affiliation(s)
- Shaozhen Song
- University of Washington, Department of Bioengineering, Seattle, WA 98195, USA
| | - Jingjiang Xu
- University of Washington, Department of Bioengineering, Seattle, WA 98195, USA
| | - Shaojie Men
- University of Washington, Department of Bioengineering, Seattle, WA 98195, USA
| | - Tueng T Shen
- University of Washington, Department of Bioengineering, Seattle, WA 98195, USA
- University of Washington, Department of Ophthalmology, Seattle, WA 98195, USA
| | - Ruikang K Wang
- University of Washington, Department of Bioengineering, Seattle, WA 98195, USA
- University of Washington, Department of Ophthalmology, Seattle, WA 98195, USA
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28
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Poddar R, Migacz JV, Schwartz DM, Werner JS, Gorczynska I. Challenges and advantages in wide-field optical coherence tomography angiography imaging of the human retinal and choroidal vasculature at 1.7-MHz A-scan rate. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-14. [PMID: 29090534 PMCID: PMC9062069 DOI: 10.1117/1.jbo.22.10.106018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 10/04/2017] [Indexed: 05/08/2023]
Abstract
We present noninvasive, three-dimensional, depth-resolved imaging of human retinal and choroidal blood circulation with a swept-source optical coherence tomography (OCT) system at 1065-nm center wavelength. Motion contrast OCT imaging was performed with the phase-variance OCT angiography method. A Fourier-domain mode-locked light source was used to enable an imaging rate of 1.7 MHz. We experimentally demonstrate the challenges and advantages of wide-field OCT angiography (OCTA). In the discussion, we consider acquisition time, scanning area, scanning density, and their influence on visualization of selected features of the retinal and choroidal vascular networks. The OCTA imaging was performed with a field of view of 16 deg (5 mm×5 mm) and 30 deg (9 mm×9 mm). Data were presented in en face projections generated from single volumes and in en face projection mosaics generated from up to 4 datasets. OCTA imaging at 1.7 MHz A-scan rate was compared with results obtained from a commercial OCTA instrument and with conventional ophthalmic diagnostic methods: fundus photography, fluorescein, and indocyanine green angiography. Comparison of images obtained from all methods is demonstrated using the same eye of a healthy volunteer. For example, imaging of retinal pathology is presented in three cases of advanced age-related macular degeneration.
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Affiliation(s)
- Raju Poddar
- University of California Davis, Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, Sacramento, California, United States
- Birla Institute of Technology, Department of Bio-Engineering, Mesra, Ranchi, Jharkhand, India
- Address all correspondence to: Raju Poddar, E-mail:
| | - Justin V. Migacz
- University of California Davis, Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, Sacramento, California, United States
| | - Daniel M. Schwartz
- University of California San Francisco, Department of Ophthalmology and Vision Science, San Francisco, California, United States
| | - John S. Werner
- University of California Davis, Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, Sacramento, California, United States
| | - Iwona Gorczynska
- University of California Davis, Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, Sacramento, California, United States
- Nicolaus Copernicus University, Institute of Physics, Toruń, Poland
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29
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de Boer JF, Leitgeb R, Wojtkowski M. Twenty-five years of optical coherence tomography: the paradigm shift in sensitivity and speed provided by Fourier domain OCT [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:3248-3280. [PMID: 28717565 PMCID: PMC5508826 DOI: 10.1364/boe.8.003248] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 04/26/2017] [Accepted: 05/22/2017] [Indexed: 05/19/2023]
Abstract
Optical coherence tomography (OCT) has become one of the most successful optical technologies implemented in medicine and clinical practice mostly due to the possibility of non-invasive and non-contact imaging by detecting back-scattered light. OCT has gone through a tremendous development over the past 25 years. From its initial inception in 1991 [Science254, 1178 (1991)] it has become an indispensable medical imaging technology in ophthalmology. Also in fields like cardiology and gastro-enterology the technology is envisioned to become a standard of care. A key contributor to the success of OCT has been the sensitivity and speed advantage offered by Fourier domain OCT. In this review paper the development of FD-OCT will be revisited, providing a single comprehensive framework to derive the sensitivity advantage of both SD- and SS-OCT. We point out the key aspects of the physics and the technology that has enabled a more than 2 orders of magnitude increase in sensitivity, and as a consequence an increase in the imaging speed without loss of image quality. This speed increase provided a paradigm shift from point sampling to comprehensive 3D in vivo imaging, whose clinical impact is still actively explored by a large number of researchers worldwide.
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Affiliation(s)
- Johannes F. de Boer
- Department of Physics and Astronomy and LaserLaB Amsterdam, VU University, De Boelelaan 1105, 1081 HV Amsterdam, Department of Ophthalmology, VU Medical Center, Amsterdam, The Netherlands
- Authors are listed in alphabetical order and contributed equally
| | - Rainer Leitgeb
- Christian Doppler Laboratory OPTRAMED, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
- Authors are listed in alphabetical order and contributed equally
| | - Maciej Wojtkowski
- Physical Optics and Biophotonics Group, Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52 01-224 Warsaw, Poland
- Authors are listed in alphabetical order and contributed equally
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30
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Gao W. Quantitative depth-resolved microcirculation imaging with optical coherence tomography angiography (Part Ι): Blood flow velocity imaging. Microcirculation 2017; 25:e12375. [PMID: 28419622 DOI: 10.1111/micc.12375] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 04/11/2017] [Indexed: 12/20/2022]
Abstract
The research goal of the microvascular network imaging with OCT angiography is to achieve depth-resolved blood flow and vessel imaging in vivo in the clinical management of patents. In this review, we review the main phenomena that have been explored in OCT to image the blood flow velocity vector and the vessels of the microcirculation within living tissues. Parameters that limit the accurate measurements of blood flow velocity are then considered. Finally, initial clinical diagnosis applications and future developments of OCT flow images are discussed.
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Affiliation(s)
- Wanrong Gao
- Department of Optical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, China.,MIIT Key Laboratory of Advanced soIid Laser, Nanjing University of science and Technology, Nanjing, Jiangsu, China
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31
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SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY REVEALS CHORIOCAPILLARIS ALTERATIONS IN EYES WITH NASCENT GEOGRAPHIC ATROPHY AND DRUSEN-ASSOCIATED GEOGRAPHIC ATROPHY. Retina 2017; 36 Suppl 1:S2-S11. [PMID: 28005659 DOI: 10.1097/iae.0000000000001287] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE To investigate choriocapillaris (CC) alteration in patients with nascent geographic atrophy (nGA) and/or drusen-associated geographic atrophy (DAGA) using swept-source optical coherence tomography angiography (OCTA). METHODS A 1,050-nm wavelength, 400 kHz A-scan rate swept-source optical coherence tomography prototype was used to perform volumetric swept-source optical coherence tomography angiography over 6 mm × 6 mm fields of view in patients with nGA and/or DAGA. The resulting optical coherence tomography (OCT) and OCTA data were analyzed using a combination of en face and cross-sectional techniques. Variable interscan time analysis (VISTA) was used to differentiate CC flow impairment from complete CC atrophy. RESULTS A total of 7 eyes from 6 patients (mean age: 73.8 ± 5.7 years) were scanned. Seven areas of nGA and three areas of DAGA were identified. Analysis of cross-sectional OCT and OCTA images identified focal alterations of the CC underlying all seven areas of nGA and all three areas of DAGA. En face OCTA analysis of the CC revealed diffuse CC alterations in all eyes. Variable interscan time analysis processing suggested that the observed CC flow alterations predominantly corresponded to flow impairment rather than complete CC atrophy. CONCLUSION The OCTA imaging of the CC revealed focal CC flow impairment associated with areas of nGA and DAGA, as well as diffuse CC flow impairment throughout the imaged field. En face OCT analysis should prove useful for understanding the pathogenesis of nGA and DAGA and for identifying the formation of nGA and DAGA as endpoints in therapeutic trials.
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32
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Liu YZ, South FA, Xu Y, Carney PS, Boppart SA. Computational optical coherence tomography [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:1549-1574. [PMID: 28663849 PMCID: PMC5480564 DOI: 10.1364/boe.8.001549] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/09/2017] [Accepted: 02/10/2017] [Indexed: 05/18/2023]
Abstract
Optical coherence tomography (OCT) has become an important imaging modality with numerous biomedical applications. Challenges in high-speed, high-resolution, volumetric OCT imaging include managing dispersion, the trade-off between transverse resolution and depth-of-field, and correcting optical aberrations that are present in both the system and sample. Physics-based computational imaging techniques have proven to provide solutions to these limitations. This review aims to outline these computational imaging techniques within a general mathematical framework, summarize the historical progress, highlight the state-of-the-art achievements, and discuss the present challenges.
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Affiliation(s)
- Yuan-Zhi Liu
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, USA
| | - Fredrick A. South
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, USA
| | - Yang Xu
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, USA
| | - P. Scott Carney
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, USA
| | - Stephen A. Boppart
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, USA
- Departments of Bioengineering and Internal Medicine, University of Illinois at Urbana-Champaign, USA
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33
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Baghaie A, Yu Z, D'Souza RM. Involuntary eye motion correction in retinal optical coherence tomography: Hardware or software solution? Med Image Anal 2017; 37:129-145. [PMID: 28208100 DOI: 10.1016/j.media.2017.02.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 01/27/2017] [Accepted: 02/03/2017] [Indexed: 01/05/2023]
Abstract
In this paper, we review state-of-the-art techniques to correct eye motion artifacts in Optical Coherence Tomography (OCT) imaging. The methods for eye motion artifact reduction can be categorized into two major classes: (1) hardware-based techniques and (2) software-based techniques. In the first class, additional hardware is mounted onto the OCT scanner to gather information about the eye motion patterns during OCT data acquisition. This information is later processed and applied to the OCT data for creating an anatomically correct representation of the retina, either in an offline or online manner. In software based techniques, the motion patterns are approximated either by comparing the acquired data to a reference image, or by considering some prior assumptions about the nature of the eye motion. Careful investigations done on the most common methods in the field provides invaluable insight regarding future directions of the research in this area. The challenge in hardware-based techniques lies in the implementation aspects of particular devices. However, the results of these techniques are superior to those obtained from software-based techniques because they are capable of capturing secondary data related to eye motion during OCT acquisition. Software-based techniques on the other hand, achieve moderate success and their performance is highly dependent on the quality of the OCT data in terms of the amount of motion artifacts contained in them. However, they are still relevant to the field since they are the sole class of techniques with the ability to be applied to legacy data acquired using systems that do not have extra hardware to track eye motion.
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Affiliation(s)
- Ahmadreza Baghaie
- Department of Electrical Engineering, University of Wisconsin-Milwaukee, WI 53211, USA.
| | - Zeyun Yu
- Department of Computer Science, University of Wisconsin-Milwaukee, WI 53211, USA
| | - Roshan M D'Souza
- Department of Mechanical Engineering, University of Wisconsin-Milwaukee, WI 53211, USA
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34
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Johnson B, Atia W, Kuznetsov M, Goldberg BD, Whitney P, Flanders DC. Coherence properties of short cavity swept lasers. BIOMEDICAL OPTICS EXPRESS 2017; 8:1045-1055. [PMID: 28271002 PMCID: PMC5330592 DOI: 10.1364/boe.8.001045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 01/12/2017] [Accepted: 01/18/2017] [Indexed: 05/18/2023]
Abstract
It has been shown theoretically and experimentally that short cavity swept lasers are passively mode locked. We develop a mathematical model of these lasers and the light field solutions are used to predict the coherence length and coherence revival behavior. The calculations compare favorably with data from a 990-1100 nm laser swept at 100 kHz suitable for optical coherence tomography applications.
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35
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Wartak A, Haindl R, Trasischker W, Baumann B, Pircher M, Hitzenberger CK. Active-passive path-length encoded (APPLE) Doppler OCT. BIOMEDICAL OPTICS EXPRESS 2016; 7:5233-5251. [PMID: 28018739 PMCID: PMC5175566 DOI: 10.1364/boe.7.005233] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/10/2016] [Accepted: 11/20/2016] [Indexed: 05/23/2023]
Abstract
We present a novel active-passive path-length encoded (APPLE) swept source Doppler optical coherence tomography (DOCT) approach, enabling three-dimensional velocity vector reconstruction of moving particles without prior knowledge of the orientation of motion. The developed APPLE DOCT setup allows for non-invasive blood flow measurements in vivo and was primarily designed for quantitative human ocular blood flow investigations. The system's performance was demonstrated by in vitro flow phantom as well as in vivo retinal vessel bifurcation measurements. Furthermore, total retinal blood flow - a biomarker aiding in diagnosis and monitoring of major ocular diseases such as glaucoma, diabetic retinopathy or central/branch retinal vein occlusion - was determined in the eyes of healthy human volunteers.
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36
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Merkle CW, Leahy C, Srinivasan VJ. Dynamic contrast optical coherence tomography images transit time and quantifies microvascular plasma volume and flow in the retina and choriocapillaris. BIOMEDICAL OPTICS EXPRESS 2016; 7:4289-4312. [PMID: 27867732 PMCID: PMC5102529 DOI: 10.1364/boe.7.004289] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 08/19/2016] [Accepted: 09/16/2016] [Indexed: 05/18/2023]
Abstract
Despite the prevalence of optical imaging techniques to measure hemodynamics in large retinal vessels, quantitative measurements of retinal capillary and choroidal hemodynamics have traditionally been challenging. Here, a new imaging technique called dynamic contrast optical coherence tomography (DyC-OCT) is applied in the rat eye to study microvascular blood flow in individual retinal and choroidal layers in vivo. DyC-OCT is based on imaging the transit of an intravascular tracer dynamically as it passes through the field-of-view. Hemodynamic parameters can be determined through quantitative analysis of tracer kinetics. In addition to enabling depth-resolved transit time, volume, and flow measurements, the injected tracer also enhances OCT angiograms and enables clear visualization of the choriocapillaris, particularly when combined with a post-processing method for vessel enhancement. DyC-OCT complements conventional OCT angiography through quantification of tracer dynamics, similar to fluorescence angiography, but with the important added benefit of laminar resolution.
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Affiliation(s)
- Conrad W. Merkle
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
| | - Conor Leahy
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
| | - Vivek J. Srinivasan
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
- Department of Ophthalmology and Vision Science, University of California Davis School of Medicine, Sacramento, California, USA
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37
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Chen Z, Liu M, Minneman M, Ginner L, Hoover E, Sattmann H, Bonesi M, Drexler W, Leitgeb RA. Phase-stable swept source OCT angiography in human skin using an akinetic source. BIOMEDICAL OPTICS EXPRESS 2016; 7:3032-48. [PMID: 27570695 PMCID: PMC4986811 DOI: 10.1364/boe.7.003032] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 06/30/2016] [Accepted: 07/07/2016] [Indexed: 05/19/2023]
Abstract
We demonstrate noninvasive structural and microvascular contrast imaging of human skin in vivo, using phase difference swept source OCT angiography (pOCTA). The pOCTA system employs an akinetic, all-semiconductor, highly phase-stable swept laser source which operates at 1340 nm central wavelength, with 37 nm bandwidth (at 0 dB region) and 200 kHz A-scan rate. The phase sensitive detection does not need any external phase stabilizing implementations, due to the outstanding high phase linearity and sweep phase repeatability within 2 mrad. We compare the performance of phase based OCTA to speckle based OCTA for visualizing human vascular networks. pOCTA shows better contrast especially for deeper vascular details as compared to speckle based OCTA. The phase stability of the akinetic source allows the OCTA system to show decent vascular contrast only with 2 B-scans. We compare the performance of using 2 versus 4 B-scans for calculating the vascular contrast. Finally, the performance of a 100 nm bandwidth akinetic laser at 1310 nm is investigated for both OCT and OCTA.
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Affiliation(s)
- Zhe Chen
- Center of Medical Physics and Biomedical Engineering, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Mengyang Liu
- Center of Medical Physics and Biomedical Engineering, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Michael Minneman
- Insight Photonic Solutions, Inc., 300 S. Public Rd., Lafayette CO 80026, USA
| | - Laurin Ginner
- Center of Medical Physics and Biomedical Engineering, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and its Translation to Medicine, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Erich Hoover
- Insight Photonic Solutions, Inc., 300 S. Public Rd., Lafayette CO 80026, USA
| | - Harald Sattmann
- Center of Medical Physics and Biomedical Engineering, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
- Insight Photonic Solutions, Inc., 300 S. Public Rd., Lafayette CO 80026, USA
| | - Marco Bonesi
- Center of Medical Physics and Biomedical Engineering, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Wolfgang Drexler
- Center of Medical Physics and Biomedical Engineering, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Rainer A. Leitgeb
- Center of Medical Physics and Biomedical Engineering, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and its Translation to Medicine, Währinger Gürtel 18-20, 1090 Vienna, Austria
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38
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Liu G, Jia Y, Pechauer AD, Chandwani R, Huang D. Split-spectrum phase-gradient optical coherence tomography angiography. BIOMEDICAL OPTICS EXPRESS 2016; 7:2943-54. [PMID: 27570689 PMCID: PMC4986805 DOI: 10.1364/boe.7.002943] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 06/28/2016] [Accepted: 07/05/2016] [Indexed: 05/20/2023]
Abstract
A phase gradient angiography (PGA) method is proposed for optical coherence tomography (OCT). This method allows the use of phase information to map the microvasculature in tissue without the correction of bulk motion and laser trigger jitter induced phase artifacts. PGA can also be combined with the amplitude/intensity to improve the performance. Split-spectrum technique can further increase the signal to noise ratio by more than two times. In-vivo imaging of human retinal circulation is shown with a 70 kHz, 840 nm spectral domain OCT system and a 200 kHz, 1050 nm swept source OCT system. Four different OCT angiography methods are compared. The best performance was achieved with split-spectrum amplitude and phase-gradient angiography.
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39
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In vivo label-free measurement of lymph flow velocity and volumetric flow rates using Doppler optical coherence tomography. Sci Rep 2016; 6:29035. [PMID: 27377852 PMCID: PMC4932526 DOI: 10.1038/srep29035] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 06/09/2016] [Indexed: 01/08/2023] Open
Abstract
Direct in vivo imaging of lymph flow is key to understanding lymphatic system function in normal and disease states. Optical microscopy techniques provide the resolution required for these measurements, but existing optical techniques for measuring lymph flow require complex protocols and provide limited temporal resolution. Here, we describe a Doppler optical coherence tomography platform that allows direct, label-free quantification of lymph velocity and volumetric flow rates. We overcome the challenge of very low scattering by employing a Doppler algorithm that operates on low signal-to-noise measurements. We show that this technique can measure lymph velocity at sufficiently high temporal resolution to resolve the dynamic pulsatile flow in collecting lymphatic vessels.
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40
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Song S, Wei W, Hsieh BY, Pelivanov I, Shen TT, O'Donnell M, Wang RK. Strategies to improve phase-stability of ultrafast swept source optical coherence tomography for single shot imaging of transient mechanical waves at 16 kHz frame rate. APPLIED PHYSICS LETTERS 2016; 108:191104. [PMID: 27375295 PMCID: PMC4866944 DOI: 10.1063/1.4949469] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 04/25/2016] [Indexed: 05/17/2023]
Abstract
We present single-shot phase-sensitive imaging of propagating mechanical waves within tissue, enabled by an ultrafast optical coherence tomography (OCT) system powered by a 1.628 MHz Fourier domain mode-locked (FDML) swept laser source. We propose a practical strategy for phase-sensitive measurement by comparing the phases between adjacent OCT B-scans, where the B-scan contains a number of A-scans equaling an integer number of FDML buffers. With this approach, we show that micro-strain fields can be mapped with ∼3.0 nm sensitivity at ∼16 000 fps. The system's capabilities are demonstrated on porcine cornea by imaging mechanical wave propagation launched by a pulsed UV laser beam, promising non-contact, real-time, and high-resolution optical coherence elastography.
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Affiliation(s)
- Shaozhen Song
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
| | - Wei Wei
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
| | - Bao-Yu Hsieh
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
| | - Ivan Pelivanov
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
| | | | - Matthew O'Donnell
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
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Kim S, Raphael PD, Oghalai JS, Applegate BE. High-speed spectral calibration by complex FIR filter in phase-sensitive optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2016; 7:1430-44. [PMID: 27446666 PMCID: PMC4929652 DOI: 10.1364/boe.7.001430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 03/14/2016] [Accepted: 03/15/2016] [Indexed: 05/03/2023]
Abstract
Swept-laser sources offer a number of advantages for Phase-sensitive Optical Coherence Tomography (PhOCT). However, inter- and intra-sweep variability leads to calibration errors that adversely affect phase sensitivity. While there are several approaches to overcoming this problem, our preferred method is to simply calibrate every sweep of the laser. This approach offers high accuracy and phase stability at the expense of a substantial processing burden. In this approach, the Hilbert phase of the interferogram from a reference interferometer provides the instantaneous wavenumber of the laser, but is computationally expensive. Fortunately, the Hilbert transform may be approximated by a Finite Impulse-Response (FIR) filter. Here we explore the use of several FIR filter based Hilbert transforms for calibration, explicitly considering the impact of filter choice on phase sensitivity and OCT image quality. Our results indicate that the complex FIR filter approach is the most robust and accurate among those considered. It provides similar image quality and slightly better phase sensitivity than the traditional FFT-IFFT based Hilbert transform while consuming fewer resources in an FPGA implementation. We also explored utilizing the Hilbert magnitude of the reference interferogram to calculate an ideal window function for spectral amplitude calibration. The ideal window function is designed to carefully control sidelobes on the axial point spread function. We found that after a simple chromatic correction, calculating the window function using the complex FIR filter and the reference interferometer gave similar results to window functions calculated using a mirror sample and the FFT-IFFT Hilbert transform. Hence, the complex FIR filter can enable accurate and high-speed calibration of the magnitude and phase of spectral interferograms.
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Affiliation(s)
- Sangmin Kim
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Patrick D. Raphael
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, CA, USA
| | - John S. Oghalai
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, CA, USA
| | - Brian E. Applegate
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
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42
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Makita S, Kurokawa K, Hong YJ, Miura M, Yasuno Y. Noise-immune complex correlation for optical coherence angiography based on standard and Jones matrix optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2016; 7:1525-48. [PMID: 27446673 PMCID: PMC4929659 DOI: 10.1364/boe.7.001525] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 03/24/2016] [Accepted: 03/24/2016] [Indexed: 05/18/2023]
Abstract
This paper describes a complex correlation mapping algorithm for optical coherence angiography (cmOCA). The proposed algorithm avoids the signal-to-noise ratio dependence and exhibits low noise in vasculature imaging. The complex correlation coefficient of the signals, rather than that of the measured data are estimated, and two-step averaging is introduced. Algorithms of motion artifact removal based on non perfusing tissue detection using correlation are developed. The algorithms are implemented with Jones-matrix OCT. Simultaneous imaging of pigmented tissue and vasculature is also achieved using degree of polarization uniformity imaging with cmOCA. An application of cmOCA to in vivo posterior human eyes is presented to demonstrate that high-contrast images of patients' eyes can be obtained.
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Affiliation(s)
- Shuichi Makita
- Computational Optics Group, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573,
Japan
| | - Kazuhiro Kurokawa
- Computational Optics Group, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573,
Japan
| | - Young-Joo Hong
- Computational Optics Group, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573,
Japan
| | - Masahiro Miura
- Department of Ophthalmology, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Chuo, Ami, Inashiki, Ibaraki 300-0395,
Japan
| | - Yoshiaki Yasuno
- Computational Optics Group, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573,
Japan
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43
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Gorczynska I, Migacz JV, Zawadzki RJ, Capps AG, Werner JS. Comparison of amplitude-decorrelation, speckle-variance and phase-variance OCT angiography methods for imaging the human retina and choroid. BIOMEDICAL OPTICS EXPRESS 2016; 7:911-42. [PMID: 27231598 PMCID: PMC4866465 DOI: 10.1364/boe.7.000911] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 02/03/2016] [Accepted: 02/12/2016] [Indexed: 05/18/2023]
Abstract
We compared the performance of three OCT angiography (OCTA) methods: speckle variance, amplitude decorrelation and phase variance for imaging of the human retina and choroid. Two averaging methods, split spectrum and volume averaging, were compared to assess the quality of the OCTA vascular images. All data were acquired using a swept-source OCT system at 1040 nm central wavelength, operating at 100,000 A-scans/s. We performed a quantitative comparison using a contrast-to-noise (CNR) metric to assess the capability of the three methods to visualize the choriocapillaris layer. For evaluation of the static tissue noise suppression in OCTA images we proposed to calculate CNR between the photoreceptor/RPE complex and the choriocapillaris layer. Finally, we demonstrated that implementation of intensity-based OCT imaging and OCT angiography methods allows for visualization of retinal and choroidal vascular layers known from anatomic studies in retinal preparations. OCT projection imaging of data flattened to selected retinal layers was implemented to visualize retinal and choroidal vasculature. User guided vessel tracing was applied to segment the retinal vasculature. The results were visualized in a form of a skeletonized 3D model.
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Affiliation(s)
- Iwona Gorczynska
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
- Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Torun 87-100, Poland
| | - Justin V. Migacz
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
| | - Robert J. Zawadzki
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
| | - Arlie G. Capps
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
- Physics Division, Lawrence Livermore National Laboratory Livermore, CA 94550, USA
| | - John S. Werner
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA 95817, USA
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44
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Amarakoon S, de Jong JH, Braaf B, Yzer S, Missotten T, van Velthoven MEJ, de Boer JF. Phase-Resolved Doppler Optical Coherence Tomographic Features in Retinal Angiomatous Proliferation. Am J Ophthalmol 2015. [PMID: 26210860 DOI: 10.1016/j.ajo.2015.07.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE To study patients diagnosed with retinal angiomatous proliferation (RAP) based on conventional imaging techniques with phase-resolved Doppler optical coherence tomography (OCT) to detect and localize blood flow in RAP lesions; and to compare these findings to conventional imaging, which are mostly invasive and give limited information concerning intra- and transretinal blood flow. DESIGN Single-center, consecutive observational case series. METHODS Twelve treatment-naïve patients diagnosed with RAP based on fundus examination, fluorescein angiography, and indocyanine green angiography were included. Median age was 79 years (range 65-90). Patients were imaged with an experimental 1040 nm swept-source phase-resolved Doppler OCT instrument. Abnormal flow was defined as intraretinal neovascularization or retinal choroidal anastomosis. RESULTS In 11 patients adequate phase-resolved Doppler OCT images were obtained showing abnormal blood flow in the RAP lesion. In 4 patients a retinal choroidal anastomosis was found, 3 patients showed intraretinal neovascularization connected with a pigment epithelial detachment, 2 patients showed only intraretinal neovascularization, and in 2 patients flow was limited to the subretinal or sub-retinal pigment epithelial space. CONCLUSIONS Phase-resolved Doppler OCT is able to detect and localize abnormal blood flow within RAP lesions. Blood flow was mostly confined to the intraretinal structures with or without a connecting pigment epithelial detachment; in one-third of patients a retinal choroidal anastomosis was detected. The potential of angiography with phase-resolved Doppler OCT to accurately distinguish between normal and pathologic blood flow in addition to structural OCT data without invasive procedures will help to further elucidate both retinal and choroidal vascular pathologies like RAP.
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Affiliation(s)
- Sankha Amarakoon
- Rotterdam Ophthalmic Institute, Rotterdam, Netherlands; Medical Retina Service, Rotterdam Eye Hospital, Rotterdam, Netherlands
| | - Jan H de Jong
- Rotterdam Ophthalmic Institute, Rotterdam, Netherlands
| | - Boy Braaf
- Rotterdam Ophthalmic Institute, Rotterdam, Netherlands
| | - Suzanne Yzer
- Medical Retina Service, Rotterdam Eye Hospital, Rotterdam, Netherlands
| | - Tom Missotten
- Rotterdam Ophthalmic Institute, Rotterdam, Netherlands; Medical Retina Service, Rotterdam Eye Hospital, Rotterdam, Netherlands
| | - Mirjam E J van Velthoven
- Rotterdam Ophthalmic Institute, Rotterdam, Netherlands; Medical Retina Service, Rotterdam Eye Hospital, Rotterdam, Netherlands.
| | - Johannes F de Boer
- Rotterdam Ophthalmic Institute, Rotterdam, Netherlands; Institute for Lasers, Life and Biophotonics Amsterdam, Department of Physics and Astronomy, VU University, Amsterdam, Netherlands
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45
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Novosel J, Thepass G, Lemij HG, de Boer JF, Vermeer KA, van Vliet LJ. Loosely coupled level sets for simultaneous 3D retinal layer segmentation in optical coherence tomography. Med Image Anal 2015; 26:146-58. [PMID: 26401595 DOI: 10.1016/j.media.2015.08.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 07/13/2015] [Accepted: 08/20/2015] [Indexed: 11/29/2022]
Abstract
Optical coherence tomography (OCT) yields high-resolution, three-dimensional images of the retina. Reliable segmentation of the retinal layers is necessary for the extraction of clinically useful information. We present a novel segmentation method that operates on attenuation coefficients and incorporates anatomical knowledge about the retina. The attenuation coefficients are derived from in-vivo human retinal OCT data and represent an optical property of the tissue. Then, the layers in the retina are simultaneously segmented via a new flexible coupling approach that exploits the predefined order of the layers. The accuracy of the method was evaluated on 20 peripapillary scans of healthy subjects. Ten of those subjects were imaged again to evaluate the reproducibility. An additional evaluation was performed to examine the robustness of the method on a variety of data: scans of glaucoma patients, macular scans and scans by a two different OCT imaging devices. A very good agreement on all data was found between the manual segmentation performed by a medical doctor and the segmentation obtained by the automatic method. The mean absolute deviation for all interfaces in all data types varied between 1.9 and 8.5 µm (0.5-2.2 pixels). The reproducibility of the automatic method was similar to the reproducibility of the manual segmentation.
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Affiliation(s)
- Jelena Novosel
- Rotterdam Ophthalmic Institute, Rotterdam Eye Hospital, Rotterdam, The Netherlands; Quantitative Imaging Group, Faculty of Applied Physics, Delft University of Technology, Delft,Netherlands.
| | - Gijs Thepass
- Rotterdam Ophthalmic Institute, Rotterdam Eye Hospital, Rotterdam, The Netherlands.
| | - Hans G Lemij
- Glaucoma Service, Rotterdam Eye Hospital, Rotterdam, The Netherlands.
| | - Johannes F de Boer
- Department of Physics and Astronomy, VU University Amsterdam, Amsterdam, Netherlands.
| | - Koenraad A Vermeer
- Rotterdam Ophthalmic Institute, Rotterdam Eye Hospital, Rotterdam, The Netherlands.
| | - Lucas J van Vliet
- Quantitative Imaging Group, Faculty of Applied Physics, Delft University of Technology, Delft,Netherlands.
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46
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Lippok N, Villiger M, Bouma BE. Degree of polarization (uniformity) and depolarization index: unambiguous depolarization contrast for optical coherence tomography. OPTICS LETTERS 2015; 40:3954-7. [PMID: 26368685 PMCID: PMC4586115 DOI: 10.1364/ol.40.003954] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The degree of polarization (uniformity) has attracted increased interest as a functional contrast in optical coherence tomography (OCT). However, its computation from a single polarization state suggests an ambiguity that is strongly dependent on a sample's orientation. We here propose an improved metric to present depolarization with respect to the optical system rather than the propagating field. Using numerical simulations and optical frequency domain imaging, we evaluate the conventional DOP(U) for different polarization states and compare its performance with the unambiguous depolarization index.
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Affiliation(s)
- Norman Lippok
- Harvard Medical School, Boston, Massachusetts 02115, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
- Corresponding author:
| | - Martin Villiger
- Harvard Medical School, Boston, Massachusetts 02115, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
| | - Brett E. Bouma
- Harvard Medical School, Boston, Massachusetts 02115, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
- Harvard–Massachusetts Institute of Technology, Program in Health Sciences and Technology, Cambridge, Massachusetts 02142, USA
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47
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Liu G, Tan O, Gao SS, Pechauer AD, Lee B, Lu CD, Fujimoto JG, Huang D. Postprocessing algorithms to minimize fixed-pattern artifact and reduce trigger jitter in swept source optical coherence tomography. OPTICS EXPRESS 2015; 23:9824-34. [PMID: 25969023 PMCID: PMC4523376 DOI: 10.1364/oe.23.009824] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 03/19/2015] [Accepted: 03/26/2015] [Indexed: 05/19/2023]
Abstract
We propose methods to align interferograms affected by trigger jitter to a reference interferogram based on the information (amplitude/phase) at a fixed-pattern noise location to reduce residual fixed-pattern noise and improve the phase stability of swept source optical coherence tomography (SS-OCT) systems. One proposed method achieved this by introducing a wavenumber shift (k-shift) in the interferograms of interest and searching for the k-shift that minimized the fixed-pattern noise amplitude. The other method calculated the relative k-shift using the phase information at the residual fixed-pattern noise location. Repeating this wavenumber alignment procedure for all A-lines of interest produced fixed-pattern noise free and phase stable OCT images. A system incorporating these correction routines was used for human retina OCT and Doppler OCT imaging. The results from the two methods were compared, and it was found that the intensity-based method provided better results.
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Affiliation(s)
- Gangjun Liu
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Ou Tan
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Simon S. Gao
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Alex D. Pechauer
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - ByungKun Lee
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Chen D. Lu
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - James G. Fujimoto
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
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48
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Mo J, de Groot M, de Boer JF. Depth-encoded synthetic aperture optical coherence tomography of biological tissues with extended focal depth. OPTICS EXPRESS 2015; 23:4935-4945. [PMID: 25836528 DOI: 10.1364/oe.23.004935] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Optical coherence tomography (OCT) has proven to be able to provide three-dimensional (3D) volumetric images of scattering biological tissues for in vivo medical diagnostics. Unlike conventional optical microscopy, its depth-resolving ability (axial resolution) is exclusively determined by the laser source and therefore invariant over the full imaging depth. In contrast, its transverse resolution is determined by the objective's numerical aperture and the wavelength which is only approximately maintained over twice the Rayleigh range. However, the prevailing laser sources for OCT allow image depths of more than 5 mm which is considerably longer than the Rayleigh range. This limits high transverse resolution imaging with OCT. Previously, we reported a novel method to extend the depth-of-focus (DOF) of OCT imaging in Mo et al.Opt. Express 21, 10048 (2013)]. The approach is to create three different optical apertures via pupil segmentation with an annular phase plate. These three optical apertures produce three OCT images from the same sample, which are encoded to different depth positions in a single OCT B-scan. This allows for correcting the defocus-induced curvature of wave front in the pupil so as to improve the focus. As a consequence, the three images originating from those three optical apertures can be used to reconstruct a new image with an extended DOF. In this study, we successfully applied this method for the first time to both an artificial phantom and biological tissues over a four times larger depth range. The results demonstrate a significant DOF improvement, paving the way for 3D high resolution OCT imaging beyond the conventional Rayleigh range.
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49
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van Zeeburg EJT, Braaf B, Cereda MG, van Meurs JC, de Boer JF. Direct Blood Flow Measurements in a Free RPE-Choroid Graft with Phase-Resolved Doppler OCT. Transl Vis Sci Technol 2015; 4:2. [PMID: 25599010 DOI: 10.1167/tvst.4.1.2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 11/17/2014] [Indexed: 11/24/2022] Open
Abstract
PURPOSE We directly demonstrated the revascularization in a free retinal pigment epithelium (RPE)-choroid graft with direct blood flow detection by experimental phase-resolved Doppler optical coherence tomography (PRD-OCT). METHODS Seven patients with age-related macular degeneration underwent an RPE-choroid graft translocation in a prospective institutional cohort study. Spectral domain optical coherence tomography (SD-OCT) was used to measure the revascularization stage. With PRD-OCT the presence of flow was imaged postoperatively. RESULTS The PRD-OCT confirmed flow in three patients when SD-OCT indicated the afferent vessel ingrowth stage, and in all seven patients when the SD-OCT indicated the efferent vessel ingrowth stage. CONCLUSIONS The PRD-OCT study was able to detect the presence of blood flow in a free RPE-choroid graft. The PRD-OCT findings directly confirmed the revascularization that was otherwise based on the more circumstantial evidence provided by SD-OCT images and angiography. TRANSLATIONAL RELEVANCE The use of both techniques to monitor the revascularization process in a free graft in patients are an interesting example of replacing more invasive by noninvasive techniques. There is potential future use of PRD-OCT for the visualization of vascularization patterns in other pathologies.
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Affiliation(s)
- Elsbeth J T van Zeeburg
- Rotterdam Ophthalmic Institute, Rotterdam, The Netherlands ; The Rotterdam Eye Hospital, Rotterdam, The Netherlands
| | - Boy Braaf
- Rotterdam Ophthalmic Institute, Rotterdam, The Netherlands
| | | | - Jan C van Meurs
- The Rotterdam Eye Hospital, Rotterdam, The Netherlands ; Erasmus University Rotterdam, Department of Ophthalmology, Rotterdam, The Netherlands
| | - Johannes F de Boer
- Rotterdam Ophthalmic Institute, Rotterdam, The Netherlands ; LaserLaB, Department of Physics and Astronomy, VU University Amsterdam, Amsterdam, The Netherlands
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Poddar R, Kim DY, Werner JS, Zawadzki RJ. In vivo imaging of human vasculature in the chorioretinal complex using phase-variance contrast method with phase-stabilized 1-μm swept-source optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:126010. [PMID: 25517255 PMCID: PMC4269528 DOI: 10.1117/1.jbo.19.12.126010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 07/17/2014] [Accepted: 10/08/2014] [Indexed: 05/22/2023]
Abstract
We present a noninvasive phase-variance (pv)–based motion contrast method for depth-resolved imaging of the human chorioretinal complex microcirculation with a newly developed phase-stabilized high speed (100-kHz A-scans/s) 1-μm swept- ource optical coherence tomography (SSOCT) system. Compared to our previous spectral-domain (spectrometer based) pv-spectral domain OCT (SDOCT) system, this system has the advantages of higher sensitivity, reduced fringe wash-out for high blood flow speeds and deeper penetration in choroid. High phase stability SSOCT imaging was achieved by using a computationally efficient phase stabilization approach. This process does not require additional calibration hardware and complex numerical procedures. Our phase stabilization method is simple and can be employed in a variety of SSOCT systems. Examples of vasculature in the chorioretinal complex imaged by pv-SSOCT from normal as well as diseased eyes are presented and compared to retinal images of the same subjects acquired with fluorescein angiography and indocyanine green angiography. Observations of morphology of vascular perfusion in chorioretinal complex visualized by our method are listed.
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Affiliation(s)
- Raju Poddar
- University of California Davis, Department of Ophthalmology and Vision Science, Vision Science and Advanced Retinal Imaging Laboratory, Sacramento, California 95817, United States
- Birla Institute of Technology, Department of Biotechnology, Mesra, Ranchi, Jharkhand 835215, India
| | - Dae Yu Kim
- University of California Davis, Department of Ophthalmology and Vision Science, Vision Science and Advanced Retinal Imaging Laboratory, Sacramento, California 95817, United States
- Dankook University, Beckman Laser Institute Korea, Cheonan, Chungnam 330-715, Republic of Korea
| | - John S. Werner
- University of California Davis, Department of Ophthalmology and Vision Science, Vision Science and Advanced Retinal Imaging Laboratory, Sacramento, California 95817, United States
| | - Robert J. Zawadzki
- University of California Davis, Department of Ophthalmology and Vision Science, Vision Science and Advanced Retinal Imaging Laboratory, Sacramento, California 95817, United States
- Address all correspondence to: Robert J. Zawadzki, E-mail:
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