1. All Articles

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    1. Image contrast correction method in full-field optical coherence tomography

      Image contrast correction method in full-field optical coherence tomography

      An image contrast correction method is proposed for en face images obtained with full-field optical coherence tomography (FFOCT). First, the mechanism of image contrast decrease in FFOCT is considered and the theoretical models of main parameters that degrade image contrast are analyzed. Second, changes of contrast with depth are calculated under various conditions, from which the main parameters that affect contrast in tissue are identified. Then based on the analysis, the methods are proposed for correcting image contrast. Finally, the en face tomographic images of human liver tissue at different depths with and without contrast correction are presented to demonstrate ...

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    2. Evaluation of posterior vitreous detachment using ultrasonography and optical coherence tomography

      Evaluation of posterior vitreous detachment using ultrasonography and optical coherence tomography

      Purpose To compare the diagnostic ability of ultrasonography (US) and optical coherence tomography (OCT) in evaluating posterior vitreous detachment (PVD) status. Methods In total, 124 eyes in 63 patients were prospectively enrolled. Posterior vitreous detachment (PVD) status was evaluated by two examiners independently using US and OCT (transverse scan with/without peripapillary scan). By combining all examination results from both examiners, a final agreement on the PVD status was made. Inter‐observer agreement and inter‐examination agreement on PVD detection were evaluated. Results The inter‐observer agreement on PVD grading based on US was substantial (kappa = 0.628). The inter ...

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    3. Optical coherence tomography angiography characteristics of acute retinal arterial occlusion

      Optical coherence tomography angiography characteristics of acute retinal arterial occlusion

      Background To characterize the vascular changes in eyes within the acute phase of retinal arterial occlusion (RAO) by optical coherence tomography angiography (OCT-A) imaging. Methods This was a retrospective, observational study. Nineteen patients with RAO (symptom onset within 7 days) and 19 age and sex-matched normal control individuals were included. A comprehensive ophthalmic examination and OCT-A examination were conducted for all the patients. Results The vessel density of the superficial capillary plexus (SCP), deep capillary plexus (DCP), and area with a width of 300 μm around the FAZ (FD-300) was significantly reduced in RAO patients compared with that in the ...

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      Mentions: Jing Xu
    4. Computed Tomography–Mediated Registration of Trapeziometacarpal Articular Cartilage Using Intraarticular Optical Coherence Tomography and Cryomicrotome Imaging: A Cadaver Study

      Computed Tomography–Mediated Registration of Trapeziometacarpal Articular Cartilage Using Intraarticular Optical Coherence Tomography and Cryomicrotome Imaging: A Cadaver Study

      Objective Accurate, high-resolution imaging of articular cartilage thickness is an important clinical challenge in patients with osteoarthritis, especially in small joints. In this study, computed tomography (CT) mediated catheter-based optical coherence tomography (OCT) was utilized to create a digital reconstruction of the articular surface of the trapeziometacarpal (TMC) joint and to assess cartilage thickness in comparison to cryomicrotome data. Design Using needle-based introduction of the OCT probe, the articular surface of the TMC joint of 5 cadaver wrists was scanned in different probe positions with matching CT scans to record the intraarticular probe trajectory. Subsequently and based on the acquired ...

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    5. Successful Treatment of Genital Warts with Ingenol Mebutate Monitored with Optical Coherence Tomography and Reflectance Confocal Microscopy

      Successful Treatment of Genital Warts with Ingenol Mebutate Monitored with Optical Coherence Tomography and Reflectance Confocal Microscopy

      Ingenol mebutate (IM) is approved for the treatment of actinic keratosis and induces cell death in precancerous lesions. The efficacy of IM in the treatment of genital warts was investigated in a therapy-refractory patient. The 74-year-old male was treated with IM gel for three consecutive days. Treatment course and efficacy were evaluated by clinical inspection and non-invasive diagnostics namely optical coherence tomography (OCT) and reflectance confocal microscopy (RCM). Within 24 to 48 hours IM induced a strong local inflammatory reaction. One week later a complete response was observed. OCT and RCM showed a strong reaction after treatment with erosions, swelling ...

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    6. Comparison of peripapillary and subfoveal choroidal thickness in normal versus primary open-angle glaucoma (POAG) subjects using spectral domain optical coherence tomography (SD-OCT) and swept source optical coherence tomography (SS-OCT)

      Comparison of peripapillary and subfoveal choroidal thickness in normal versus primary open-angle glaucoma (POAG) subjects using spectral domain optical coherence tomography (SD-OCT) and swept source optical coherence tomography (SS-OCT)

      Objective To elucidate the difference between choroidal thickness (CT) in primary open-angle glaucoma (POAG) and normal subjects and to compare the CT measured using spectral domain optical coherence tomography (SD-OCT) and swept source optical coherence tomography (SS-OCT). Methods and analysis This cross-sectional observational study included 25 eyes of 17 POAG subjects (cases) and 31 eyes of 20 normal subjects (controls). All the patients underwent complete ophthalmologic examination, enhanced depth imaging, SD-OCT and SS-OCT. In both controls and cases, the CT was measured in seven predetermined points in macular and peripapillary area and were compared. Results Choroid was significantly thicker on ...

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    7. Methods for Quantifying Optic Disc Volume and Peripapillary Deflection Volume Using Radial Optical Coherence Tomography Scans and Association with Intracranial Pressure

      Methods for Quantifying Optic Disc Volume and Peripapillary Deflection Volume Using Radial Optical Coherence Tomography Scans and Association with Intracranial Pressure

      Purpose: Papilledema and peripapillary deformation of Bruch’s membrane(BM) are associated with elevated intracranial pressure(ICP). We have developed a novel methodology to measure these parameters using a radial optical coherence tomography(OCT) scan pattern and apply this to test the hypothesis that ICP is associated with volumetric features of ophthalmic structures. Methods: 6-radial OCT B-scans centered over the optic nerve head were acquired in 17 subjects(30 eyes) before lumbar puncture with measurement of ICP(range:10-55 cm H2O). Internal limiting membrane(ILM) and BM were segmented. Three definitions of BM were studied to account for imaging artifact ...

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    8. Disease classification of macular Optical Coherence Tomography scans using deep learning software: validation on independent, multi-centre data

      Disease classification of macular Optical Coherence Tomography scans using deep learning software: validation on independent, multi-centre data

      Purpose: To evaluate Pegasus-OCT, a clinical decision support software for the identification of features of retinal disease from macula OCT scans, across heterogenous populations involving varying patient demographics, device manufacturers, acquisition sites and operators. Methods: 5,588 normal and anomalous macular OCT volumes (162,721 B-scans), acquired at independent centres in five countries, were processed using the software. Results were evaluated against ground truth provided by the dataset owners. Results: Pegasus-OCT performed with AUROCs of at least 98% for all datasets in the detection of general macular anomalies. For scans of sufficient quality, the AUROCs for general AMD and DME ...

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    9. Optical coherence tomography-based patient-specific coronary artery reconstruction and fluid–structure interaction simulation

      Optical coherence tomography-based patient-specific coronary artery reconstruction and fluid–structure interaction simulation

      Plaque rupture is related to the mechanical stress it suffered. The value and distribution of the mechanical stress in plaque could help on assessing plaque vulnerability. To look into the stress conditions in the coronary artery, a patient-specific coronary model was created by using optical coherence tomography (OCT) and angiography imaging data. The reconstructed coronary model consisted of the structure of the lumen, the arterial wall and plaque components. Benefited by the high resolution of OCT, detailed structures such as the thin fibrous cap could be observed and built into the geometry. On this reconstructed coronary model, a fully coupled ...

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    10. Optical coherence tomography of the retina, nerve fiber layer, and optic nerve head in dogs with glaucoma

      Optical coherence tomography of the retina, nerve fiber layer, and optic nerve head in dogs with glaucoma

      Objective To evaluate the retina and optic nerve head (ONH) in canine eyes predisposed to glaucoma using optical coherence tomography (OCT). Animals Twenty‐five eyes (24 dogs). Methods Measures of peripapillary retinal, retinal nerve fiber layer (RNFL), and ganglion cell complex (GCC) thickness and ONH parameters were obtained in vivo by OCT of the unaffected eye in dogs diagnosed with unilateral primary glaucoma (predisposed; n = 12) and compared with measures of healthy control eyes (normal; n = 13). Repeatability and intrarater reliability were explored using intraclass correlation coefficients (ICC). Results Compared to normal eyes, predisposed eyes had a thinner retina in ...

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    11. MGH Receives NIH Grant for Quantitative Biomechanics Imaging

      MGH Receives NIH Grant for Quantitative Biomechanics Imaging

      Massachusetts General Hospital Receives a 2019 NIH Grant for $340,916 for Quantitative Biomechanics Imaging. The principal investigator is Seok-Hyun Andy Yun. The program began in 2019 and ends in 2020. Below is a summary of the proposed work. TRD 1 The proposed research in TRD Project 1 is to develop novel optical coherence tomography (OCT)-based techniques and tools for measuring the mechanical properties and parameters as well as acoustic transduction in tissues. The focus on tissue biomechanics responds to the emerging opportunity to harness OCT's unique capabilities to obtain quantitative maps of tissue vibration, deformation, strain, and ...

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    12. MGH Receives NIH Grant for: Percutaneous and Interstitial Imaging

      MGH Receives NIH Grant for: Percutaneous and Interstitial Imaging

      Massachusetts General Hospital Receives a 2019 NIH Grant for $317,085 for TRD23: Percutaneous and Interstitial Imaging. The principal investigator is Martin Villiger. The program began in 2019 and ends in 2020. Below is a summary of the proposed work. TRD 3 The overall goal of TRD 3 is to enable advanced OCT imaging, with high resolution and functional and dynamic contrast, inside the living body, through narrow diameter, rotational probes. Instruments and algorithms will be developed that overcome fundamental barriers, intrinsic to flexible, rotational fiber-optic probes, that have previously compromised image quality and prohibited the integration of functional and ...

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    13. MGH Receives NIH Grant for TRD: Functional Imaging

      MGH Receives  NIH Grant  for TRD: Functional Imaging

      Massachusetts General Hospital Receives a 2019 NIH Grant for $338,551 for TRD: Functional Imaging. The principal investigator is Benjamin Vakoc. The program began in 2019 and ends in 2021. Below is a summary of the proposed work. TRD 2 TRD project 2 will develop novel optical coherence tomography (OCT) technologies to address unmet needs in the functional imaging of tissue. Specific Aim #1 addresses the need for high-speed and high- resolution angiographic imaging systems for preclinical research. A new high-speed optical architecture for high-resolution optical coherence microscopy (OCM) will be constructed that is 100 times faster than existing OCM ...

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    14. MGH Receives NIH Grant for the Center for Biomedical OCT Research and Translation

      MGH Receives  NIH Grant for the Center for Biomedical OCT Research and Translation

      Massachusetts General Hospital Receives a 2019 NIH Grant for $749,999 for the Center for Biomedical OCT Research and Translation. The principal investigator is Brett Bouma. The program began in 2011 and ends in 2021. Below is a summary of the proposed work. Overall the Center for Biomedical OCT Research and Translation seeks to push the technological frontier of optical coherence tomography instrumentation and methods in response to challenges in biology and medicine. Fundamental to our approach, CBORT thrives on an intimate, push-pull relationship between physicists/engineers and biological, pre-clinical and clinical scientists. The most direct impact o the Resource ...

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    15. UIUC Receives NIH Grant for Integration of Raman Spectroscopy and OCT for In-vivo identification of Bacterial Otitis Media

      UIUC Receives NIH Grant for Integration of Raman Spectroscopy and OCT  for In-vivo identification of Bacterial Otitis Media

      University of Illinois at Urbana Champaign Receives a 2019 NIH Grant for $648,154 for Integration of Raman Spectroscopy and Optical Coherence Tomography (RS-OCT) for In-vivo identification of Bacterial Otitis Media. The principal investigator is Stephen Boppart. The program began in 2019 and ends in 2023. Below is a summary of the proposed work. Otitis media (middle ear infection) is a highly prevalent disease, especially in young children. It has been documented that more than 75% of children will have at least one episode of otitis media (OM) by age 3, and many children will have recurrent or chronic OM ...

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    16. ZEISS Marks Milestone for its New North America High Tech Site in Dublin, California

      ZEISS Marks Milestone for its New North America High Tech Site in Dublin, California

      The internationally leading optics and optoelectronics technology enterprise ZEISS completed the “steel topping out” phase of its new high tech site in the San Francisco Bay Area. The new site in Dublin is an integral part of ZEISS’ global investment strategy and is one element in a string of international projects aimed at expanding, modernizing and realigning sites that ZEISS has been implementing in locations such as Germany, Europe and Asia since 2011. “Our investments are focused on leveraging the existing potential in our growth markets,” explains Dr. Christian Mueller, Member of the Executive Board and CFO of the ZEISS ...

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    17. Using Optical Coherence Tomography to Make Needle Biopsies Safer

      Using Optical Coherence Tomography to Make Needle Biopsies Safer

      Stereotactic needle biopsy continues to be widely employed in the diagnosis of intracranial lesions. Despite an overall low complication rate, hemorrhage remains one the most common and potentially serious risks of the procedure. Previous series have reported a symptomatic hemorrhage rate of 3% to 6%, with a minority requiring craniotomy and hemorrhage evacuation. 1-4 Though certain factors inherent to the lesion or the patient have been known to increase hemorrhage risk, 2 , 3 up until this point there has been little that surgeons can do intraoperatively to avoid hemorrhage after a trajectory has been selected. A new report in Science ...

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    18. Quantification of choriocapillaris with OCTA: a comparison study

      Quantification of choriocapillaris with OCTA: a comparison study

      Purpose To demonstrate the variation in quantitative choriocapillaris (CC) metrics with various binarization approaches using optical coherence tomography angiography (OCTA). Design Retrospective, observational, cross-sectional case series. Methods 3x3 mm and 6x6 mm macular OCTA scans were obtained from normal eyes and from eyes with drusen secondary to AMD. The CC slab was extracted and the CC flow deficits (FDs) were segmented with two previously published algorithms: fuzzy C-means approach (FCM method) and Phansalkar’s local thresholding (Phansalkar method). Four different values for the radius were used in order to investigate the effect on the FD segmentation when using the Phansalkar ...

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    19. Optical coherence tomography (OCT) data processing method, storage medium storing program for executing the OCT data processing method, and processing device

      Optical coherence tomography (OCT) data processing method, storage medium storing program for executing the OCT data processing method, and processing device

      An Optical Coherence Tomography (OCT) data processing apparatus includes an acquisition unit configured to acquire three dimensional (3-D) OCT data of an object to be inspected, a generation unit configured to generate a motion contrast image based on the 3-D OCT data, and a detection unit configured to detect a inner surface coordinate of a vessel wall based on position information of an edge of a vessel region in the motion contrast image.

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    20. Systems and methods for quantitative assessment of microvasculature using optical coherence tomography angiography

      Systems and methods for quantitative assessment of microvasculature using optical coherence tomography angiography

      A five-index quantitative analysis of OCT angiograms is disclosed. One method of analyzing an anatomical region of interest of a subject includes acquiring vascular image data from the region of interest and generating a binary vasculature map from the vascular image data. A vessel skeleton map and vessel perimeter map are generated from the binary vasculature map. Based on the three generated maps, a vessel area density, vessel skeleton density, vessel perimeter index, vessel diameter index, and vessel complexity can be determined, in addition to detection of any flow impairment zones in the region of interest. These metrics can be ...

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    21. Illusion or reality? How 3-dimensional optical coherence tomography overcomes the limitations of angiography: OCT-guided percutaneous coronary intervention of left main stem disease involving LAD/LCx bifurcation

      Illusion or reality? How 3-dimensional optical coherence tomography overcomes the limitations of angiography: OCT-guided percutaneous coronary intervention of left main stem disease involving LAD/LCx bifurcation

      Angiography is still the workhorse imaging approach for the vast majority of percutaneous coronary revascularization (PCR) cases. However, the limitations of angiographic guidance for coronary procedures have been well established. This case report demonstrates how 3-dimensional optical coherence tomography (3D OCT) can change the treatment strategy, which, had only the angiography results been considered, seemed to be straightforward. A 67-year-old male patient presented with non-ST-elevation myocardial infarction. A coronary angiogram revealed a tight lesion of the proximal left anterior descending artery (LAD). Angiographically, the vessel ostium appeared not to be involved. To clarify the disease border and determine the right ...

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    22. Ocular coherence tomography for the diagnosis of Descemet's detachment after deep sclerectomy and resolution after intracameral air injection

      Ocular coherence tomography for the diagnosis of Descemet's detachment after deep sclerectomy and resolution after intracameral air injection

      Purpose to report the use of optical coherence tomography (OCT) in a case of Descemet's membrane detachment (DMD) secondary to a nonpenetrating deep sclerectomy (NPDS) and the efficacy of intracameral air injection for management. Observations DMD was identified by anterior segment OCT (AS-OCT) in a 61-year-old male patient who was blind in the right eye and had advanced open angle glaucoma. This patient underwent NPDS in the left eye and developed localized corneal edema postoperatively. Air was injected into the anterior chamber resulting in reattachment of Descemet's membrane and resolution of corneal edema. Conclusions and Importance: This case ...

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    23. Identification of Retinal Biomarkers in Alzheimer’s Disease Using Optical Coherence Tomography: Recent Insights, Challenges, and Opportunities

      Identification of Retinal Biomarkers in Alzheimer’s Disease Using Optical Coherence Tomography: Recent Insights, Challenges, and Opportunities

      This review will highlight recent insights into measuring retinal structure in Alzheimer’s disease (AD). A growing body of evidence indicates that disturbances in retinal blood flow and structure are related to cognitive function, which can severely impair vision. Optical coherence tomography (OCT) is an optical imaging technology that may allow researchers and physicians to gain deeper insights into retinal morphology and clarify the impact of AD on retinal health and function. Direct and noninvasive measurement of retinal morphology using OCT has provided useful diagnostic and therapeutic indications in several central nervous system (CNS) diseases, including AD, multiple sclerosis, and ...

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    24. SPECTRAL CALIBRATION FOR SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY BASED ON B-SCAN DOPPLER SHIFT WITH IN SITU. TISSUE IMAGES (Thesis)

      SPECTRAL CALIBRATION FOR SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY BASED ON B-SCAN DOPPLER SHIFT WITH IN SITU. TISSUE IMAGES (Thesis)

      We propose a simple method of linearizing spectral interference fringes of spectral domain optical coherence tomography (SDOCT) based on B-scan Doppler frequency shift (DFS), which can be obtained by offsetting the laser beam from the pivot of a scanning mirror. We show that DFS is proportional to wavenumber. A DFS curve can be then extracted from either a single mirror image or multiple tissue images. By examining the convergence of the nonlinear coefficients of the DFS curve fitted with a polynomial equation, in situ. tissue images themselves can be used to linearize the wavenumber without requiring mirror images or additional ...

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