1. Articles from Joseph A. Gardecki

    1-18 of 18
    1. Imaging the Human Prostate Gland Using 1-μm-Resolution Optical Coherence Tomography

      Imaging the Human Prostate Gland Using 1-μm-Resolution Optical Coherence Tomography

      Context.— The accuracy of needle biopsy for the detection of prostate cancer is limited by well-known sampling errors. Thus, there is an unmet need for a microscopic screening tool that can screen large regions of the prostate comprehensively for cancer. Previous prostate imaging by optical coherence tomography (OCT) has had insufficient resolution for imaging cellular features related to prostate cancer. We have recently developed micro-optical coherence tomography (μOCT) that generates depth-resolved tissue images at a high frame rate with an isotropic resolution of 1 μm. Objective.— To demonstrate that optical images obtained with μOCT provide cellular-level contrast in prostate specimens ...

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    2. Imaging the Human Prostate Gland Using 1-μm-Resolution Optical Coherence Tomography

      Imaging the Human Prostate Gland Using 1-μm-Resolution Optical Coherence Tomography

      Context.— The accuracy of needle biopsy for the detection of prostate cancer is limited by well-known sampling errors. Thus, there is an unmet need for a microscopic screening tool that can screen large regions of the prostate comprehensively for cancer. Previous prostate imaging by optical coherence tomography (OCT) have had insufficient resolution for imaging cellular features related to prostate cancer. We have recently developed micro-optical coherence tomography (μOCT) that generates depth-resolved tissue images at a high frame rate with an isotropic resolution of 1 μm. Objective.— To demonstrate that optical images obtained with μOCT provide cellular-level contrast in prostate specimens ...

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    3. Contrast enhancement of microscopic birefringent crystals using polarization sensitive micro-optical coherence tomography

      Contrast enhancement of microscopic birefringent crystals using polarization sensitive micro-optical coherence tomography

      Background: Birefringent crystals such as cholesterol and monosodium urate have recently been identified as possible pharmacologic targets for the treatment of coronary artery disease. The size of these crystals can be very small (on the order of 1 µm), making them difficult to identify. To image these microscopic crystals and enhance contrast, we modified existing micro optical coherence tomography system so that it was capable of obtaining polarization-sensitive images (PS-µOCT). A spectrometer-based PS-µOCT system was developed using a 270 nm wide broadband light source centered at 765 nm. Light was polarized using a polarizer and coupled to a ...

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    4. Cellular-resolution, extended depth of focus optical coherence tomography catheter toward in vivo cardiovascular imaging

      Cellular-resolution, extended depth of focus optical coherence tomography catheter toward in vivo cardiovascular imaging

      Optical coherence tomography (OCT) has been a useful clinical tool for diagnosing coronary artery disease through a flexible catheter, but its full promise relies on resolving cellular and sub-cellular structures in vivo. Previously, visualizing cellular structures through an imaging catheter is not possible due to limited depth of focus (DOF) of a tightly focused Gaussian beam: typically, a Gaussian beam with 2-3 μm resolution has a DOF within 100 μm, which is not sufficient for in vivo catheter imaging. Therefore, we developed a self-imaging wavefront division optical system that generates a coaxially-focused multimode (CAFM) beam with a DOF that is ...

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    5. In-line optical fiber metallic mirror reflector for monolithic common path optical coherence tomography probes

      In-line optical fiber metallic mirror reflector for monolithic common path optical coherence tomography probes

      Background and Objectives Endoscopic optical coherence tomography probes suffer from various artifacts due to dispersion imbalance and polarization mismatch between reference and sample arm light. Such artifacts can be minimized using a common path approach. In this work, we demonstrate a miniaturized common path probe for optical coherence tomography using an inline fiber mirror. Materials and Methods A common path optical fiber probe suitable for performing high-resolution endoscopic optical coherence tomography imaging was developed. To achieve common path functionality, an inline fiber mirror was fabricated using a thin gold layer. A commercially available swept source engine was used to test ...

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    6. Extended depth of focus for coherence-based cellular imaging

      Extended depth of focus for coherence-based cellular imaging

      Improving lateral resolution for cross-sectional optical coherence tomography (OCT) imaging is difficult due to the rapid divergence of light once it is focused to a small spot. To overcome this obstacle, we introduce a fiber optics system that generates a coaxially focused multimode (CAFM) beam for depth of focus (DOF) extension. We fabricated a CAFM beam OCT probe and show that the DOF is more than fivefold that of a conventional Gaussian beam, enabling cross-sectional imaging of biological tissues with clearly resolved cellular and subcellular structures over more than a 400 μm depth range. The compact and straightforward design and ...

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    7. Flexible, high-resolution micro-optical coherence tomography endobronchial probe toward in vivo imaging of cilia

      Flexible, high-resolution micro-optical coherence tomography endobronchial probe toward in vivo imaging of cilia

      We report the design and fabrication of a flexible, longitudinally scanning high-resolution micro-optical coherence tomography (μOCT) endobronchial probe, optimized for micro-anatomical imaging in airways. The 2.4 mm diameter and flexibility of the probe allows it to be inserted into the instrument channel of a standard bronchoscope, enabling real-time video guidance of probe placement. To generate a depth-of-focus enhancing annular beam, we utilized a new fabrication method, whereby a hollow glass ferrule was angle-polished and gold-coated to produce an elongated annular reflector. We present validation data that verifies the preservation of linear scanning, despite the use of flexible materials. When ...

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    8. Clinical Characterization of Coronary Atherosclerosis With Dual-Modality OCT and Near-Infrared Autofluorescence Imaging

      Clinical Characterization of Coronary Atherosclerosis With Dual-Modality OCT and Near-Infrared Autofluorescence Imaging

      Objectives We present the clinical imaging of human coronary arteries in vivo using a multimodality optical coherence tomography (OCT) and near-infrared autofluorescence (NIRAF) intravascular imaging system and catheter. Background Although intravascular OCT is capable of providing microstructural images of coronary atherosclerotic lesions, it is limited in its capability to ascertain the compositional/molecular features of plaque. A recent study in cadaver coronary plaque showed that endogenous NIRAF is elevated in necrotic core lesions. The combination of these 2 technologies in 1 device may therefore provide synergistic data to aid in the diagnosis of coronary pathology in vivo. Methods We developed ...

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    9. Ex vivo catheter-based imaging of coronary atherosclerosis using multimodality OCT and NIRAF excited at 633 nm

      Ex vivo catheter-based imaging of coronary atherosclerosis using multimodality OCT and NIRAF excited at 633 nm

      While optical coherence tomography (OCT) has been shown to be capable of imaging coronary plaque microstructure, additional chemical/molecular information may be needed in order to determine which lesions are at risk of causing an acute coronary event. In this study, we used a recently developed imaging system and double-clad fiber (DCF) catheter capable of simultaneously acquiring both OCT and red excited near-infrared autofluorescence (NIRAF) images (excitation: 633 nm, emission: 680nm to 900nm). We found that NIRAF is elevated in lesions that contain necrotic core – a feature that is critical for vulnerable plaque diagnosis and that is not readily discriminated ...

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    10. Innovations in Microscopic Imaging of Atherosclerosis and Valvular Disease (Book Chapter)

      Innovations in Microscopic Imaging of Atherosclerosis and Valvular Disease (Book Chapter)

      Calcific aortic valve disease (CAVD) is still an unsolved medical problem, because the pathogenesis of CAVD is poorly understood and early calcification is hard to identify. The lack of high-resolution imaging tools to study early stage disease further hampers the search for therapeutic targets. Micro-optical coherence tomography (μOCT), which is a new form of OCT, is the highest-resolution cross-sectional OCT technology available today with 1 μm resolution. We used μOCT to visualize detailed cellular and subcellular structure associated with early calcific changes in diseased human and murine aortic valves. The results suggest that μOCT imaging has the potential to provide ...

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    11. Systems, methods and computer-accessible medium which provide microscopic images of at least one anatomical structure at a particular resolution

      Systems, methods and computer-accessible medium which provide microscopic images of at least one anatomical structure at a particular resolution

      Exemplary embodiments of systems and methods can be provided which can generate data associated with at least one portion of a sample. For example, at least one first radiation can be forwarded to the portion through at least one optical arrangement. At least one second radiation can be received from the portion which is based on the first radiation. Based on an interaction between the optical arrangement and the first radiation and/or the second radiation, the optical arrangement can have a first transfer function. Further, it is possible to forward at least one third radiation to the portion through ...

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    12. Optical Coherence Tomography in Coronary Artery Disease: Toward Sub cellular Imaging

      Optical Coherence Tomography in Coronary Artery  Disease: Toward Sub cellular Imaging

      Intracoronary optical coherence tomography (OCT) is an interferometric imaging technology that uses near-infrared light to provide cross-sectional images with an axial resolution of 10 μm and a transverse of 20-40 μm in vivo. The imaging capabilities of OCT have enabled visualization of important features of coronary plaque, including thrombus, macrophage, neovascularization, stent implantation and stent strut coverage, which have provided new insights for better understanding of this disease. Frequency domain (FD)-OCT is secondgeneration form of OCT that is able to acquire OCT images at a much higher frame. The high-speed imaging capabilities of FD-OCT have made intravascular OCT practical ...

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    13. Feasibility of the Assessment of Cholesterol Crystals in Human Macrophages Using Micro Optical Coherence Tomography

      Feasibility of the Assessment of Cholesterol Crystals in Human Macrophages Using Micro Optical Coherence Tomography

      The presence of cholesterol crystals is a hallmark of atherosclerosis, but until recently, such crystals have been considered to be passive components of necrotic plaque cores. Recent studies have demonstrated that phagocytosis of cholesterol crystals by macrophages may actively precipitate plaque progression via an inflammatory pathway, emphasizing the need for methods to study the interaction between macrophages and crystalline cholesterol. In this study, we demonstrate the feasibility of detecting cholesterol in macrophages in situ using Micro-Optical Coherence Tomography (µOCT), an imaging modality we have recently developed with 1-µm resolution. Macrophages containing cholesterol crystals frequently demonstrated highly scattering constituents in ...

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    14. Esophageal-guided biopsy with volumetric laser endomicroscopy and laser cautery marking: a pilot clinical study

      Esophageal-guided biopsy with volumetric laser endomicroscopy and laser cautery marking: a pilot clinical study

      Background Biopsy surveillance protocols for the assessment of Barrett's esophagus can be subject to sampling errors, resulting in diagnostic uncertainty. Optical coherence tomography is a cross-sectional imaging technique that can be used to conduct volumetric laser endomicroscopy (VLE) of the entire distal esophagus. We have developed a biopsy guidance platform that places endoscopically visible marks at VLE-determined biopsy sites. Objective The objective of this study was to demonstrate in human participants the safety and feasibility of VLE-guided biopsy in vivo. Design A pilot feasibility study. Setting Massachusetts General Hospital. Patients A total of 22 participants were enrolled from January ...

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    15. Feature Of The Week 1/12/14: MGH Researchers Demonstrate a Dual-Modality Optical Coherence Tomography & Near Infrared Spectroscopy System and Catheter for Intravascular Imaging

      Feature Of The Week 1/12/14: MGH Researchers Demonstrate a Dual-Modality Optical Coherence Tomography & Near Infrared Spectroscopy System and Catheter for Intravascular Imaging

      Intravascular optical coherence tomography (IVOCT) provides three-dimensional microscopic images of blood vessels, including coronary arteries, in vivo. The ability of IVOCT to capture arterial microstructural detail is potentially very useful in medicine because it enables coronary artery disease (CAD) treatment decisions to be made based on detailed morphologic information, which should result in better interventional outcomes. Furthermore, in vivo microscopy via IVOCT may provide information, such as presence of macrophage accumulations and thickness of fibrous caps, that aids the detection of the so-called “vulnerable plaque” that is a precursor lesion to acute myocardial infarction. Advancing understanding and improving diagnosis of ...

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    16. Optical coherence tomography – near infrared spectroscopy system and catheter for intravascular imaging

      Optical coherence tomography – near infrared spectroscopy system and catheter for intravascular imaging

      Owing to its superior resolution, intravascular optical coherence tomography (IVOCT) is a promising tool for imaging the microstructure of coronary artery walls. However, IVOCT does not identify chemicals and molecules in the tissue, which is required for a more complete understanding and accurate diagnosis of coronary disease. Here we present a dual-modality imaging system and catheter that uniquely combines IVOCT with diffuse near-infrared spectroscopy (NIRS) in a single dual-modality imaging device for simultaneous acquisition of microstructural and compositional information. As a proof-of-concept demonstration, the device has been used to visualize co-incident microstructural and spectroscopic information obtained from a diseased cadaver ...

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    17. Depth resolved detection of lipid using spectroscopic optical coherence tomography

      Depth resolved detection of lipid using spectroscopic optical coherence tomography

      Optical frequency domain imaging (OFDI) can identify key components related to plaque vulnerability but can suffer from artifacts that could prevent accurate identification of lipid rich regions. In this paper, we present a model of depth resolved spectral analysis of OFDI data for improved detection of lipid. A quadratic Discriminant analysis model was developed based on phantom compositions known chemical mixtures and applied to a tissue phantom of a lipid-rich plaque. We demonstrate that a combined spectral and attenuation model can be used to predict the presence of lipid in OFDI images.

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    1-18 of 18
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    1. (18 articles) Massachusetts General Hospital
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    Depth resolved detection of lipid using spectroscopic optical coherence tomography Optical coherence tomography – near infrared spectroscopy system and catheter for intravascular imaging Feature Of The Week 1/12/14: MGH Researchers Demonstrate a Dual-Modality Optical Coherence Tomography & Near Infrared Spectroscopy System and Catheter for Intravascular Imaging Esophageal-guided biopsy with volumetric laser endomicroscopy and laser cautery marking: a pilot clinical study Feasibility of the Assessment of Cholesterol Crystals in Human Macrophages Using Micro Optical Coherence Tomography Optical Coherence Tomography in Coronary Artery  Disease: Toward Sub cellular Imaging Systems, methods and computer-accessible medium which provide microscopic images of at least one anatomical structure at a particular resolution Ex vivo catheter-based imaging of coronary atherosclerosis using multimodality OCT and NIRAF excited at 633 nm Clinical Characterization of Coronary Atherosclerosis With Dual-Modality OCT and Near-Infrared Autofluorescence Imaging Flexible, high-resolution micro-optical coherence tomography endobronchial probe toward in vivo imaging of cilia Optical coherence tomography angiography of foveal neovascularisation in proliferative diabetic retinopathy Treating port wine stain birthmarks using dynamic optical coherence tomography-guided setting