1. Articles from Madhusudhana Gargesha

    1-12 of 12
    1. Three-dimensional registration of intravascular optical coherence tomography and cryo-image volumes for microscopic-resolution validation

      Three-dimensional registration of intravascular optical coherence tomography and cryo-image volumes for microscopic-resolution validation

      Evidence suggests high-resolution, high-contrast, 100    frames / s 100  frames/s intravascular optical coherence tomography (IVOCT) can distinguish plaque types, but further validation is needed, especially for automated plaque characterization. We developed experimental and three-dimensional (3-D) registration methods to provide validation of IVOCT pullback volumes using microscopic, color, and fluorescent cryo-image volumes with optional registered cryo-histology. A specialized registration method matched IVOCT pullback images acquired in the catheter reference frame to a true 3-D cryo-image volume. Briefly, an 11-parameter registration model including a polynomial virtual catheter was initialized within the cryo-image volume, and perpendicular images were extracted, mimicking IVOCT image acquisition ...

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    2. Processing to determine optical parameters of atherosclerotic disease from phantom and clinical intravascular optical coherence tomography three-dimensional pullbacks

      Processing to determine optical parameters of atherosclerotic disease from phantom and clinical intravascular optical coherence tomography three-dimensional pullbacks

      Analysis of intravascular optical coherence tomography (IVOCT) data has potential for real-time in vivo plaque classification. We developed a processing pipeline on a three-dimensional local region of support for estimation of optical properties of atherosclerotic plaques from coronary artery, IVOCT pullbacks. Using realistic coronary artery disease phantoms, we determined insignificant differences in mean and standard deviation estimates between our pullback analyses and more conventional processing of stationary acquisitions with frame averaging. There was no effect of tissue depth or oblique imaging on pullback parameter estimates. The method’s performance was assessed in comparison with observer-defined standards using clinical pullback data ...

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    3. 3D registration of intravascular optical coherence tomography and cryo-image volumes for microscopic-resolution validation

      3D registration of intravascular optical coherence tomography and cryo-image volumes for microscopic-resolution validation

      High resolution, 100 frames/sec intravascular optical coherence tomography (IVOCT) can distinguish plaque types, but further validation is needed, especially for automated plaque characterization. We developed experimental and 3D registration methods, to provide validation of IVOCT pullback volumes using microscopic, brightfield and fluorescent cryoimage volumes, with optional, exactly registered cryo-histology. The innovation was a method to match an IVOCT pullback images, acquired in the catheter reference frame, to a true 3D cryo-image volume. Briefly, an 11-parameter, polynomial virtual catheter was initialized within the cryo-image volume, and perpendicular images were extracted, mimicking IVOCT image acquisition. Virtual catheter parameters were optimized to ...

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    4. Parameter estimation of atherosclerotic tissue optical properties from three-dimensional intravascular optical coherence tomography

      Parameter estimation of atherosclerotic tissue optical properties from three-dimensional intravascular optical coherence tomography

      We developed robust, three-dimensional methods, as opposed to traditional A-line analysis, for estimating the optical properties of calcified, fibrotic, and lipid atherosclerotic plaques from in vivo coronary artery intravascular optical coherence tomography clinical pullbacks. We estimated attenuation μ t and backscattered intensity I 0 from small volumes of interest annotated by experts in 35 pullbacks. Some results were as follows: noise reduction filtering was desirable, parallel line (PL) methods outperformed individual line methods, root mean square error was the best goodness-of-fit, and α -trimmed PL ( α -T-PL) was the best overall method. Estimates of μ t were calcified ( 3.84 ± 0.95     mm − 1 ...

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    5. Volumetric Characterization of Human Coronary Calcification by Frequency-Domain Optical Coherence Tomography.

      Volumetric Characterization of Human Coronary Calcification by Frequency-Domain Optical Coherence Tomography.

      Background: Coronary artery calcification (CAC) presents unique challenges for percutaneous coronary intervention. Calcium appears as a signal-poor region with well-defined borders by frequency-domain optical coherence tomography (FD-OCT). The objective of this study was to demonstrate the accuracy of intravascular FD-OCT to determine the distribution of CAC. Methods and Results: Cadaveric coronary arteries were imaged using FD-OCT at 100-μm frame interval. Arteries were subsequently frozen, sectioned and imaged at 20-μm intervals using the Case Cryo-Imaging automated system TM . Full volumetric co-registration between FD-OCT and cryo-imaging was performed. Calcium area, calcium-lumen distance (depth) and calcium angle were traced on every ...

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    6. Feature Of The Week 1/20/13: CWRU Demonstrates Automatic Stent Detection in Intravascular OCT Images Using Bagged Decision Trees

      Feature Of The Week 1/20/13: CWRU Demonstrates Automatic Stent Detection in Intravascular OCT Images Using Bagged Decision Trees

      Cardiovascular disease is the leading cause of death worldwide. Stent implantation by means of percutaneous coronary intervention is the most common coronary revascularization procedure. Intravascular Optical Coherence Tomography (iOCT) is the only imaging modality with the resolution and contrast necessary to enable accurate measurements of luminal architecture and neointima stent coverage. Manual analysis of intravascular OCT pullbacks is time consuming, limiting the size and number of studies that can be performed. We developed a highly automated method for detecting stent struts and measuring tissue coverage. Candidate struts were first identified using image processing techniques. We trained a bagged decision trees ...

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    7. Automatic stent detection in intravascular OCT images using bagged decision trees

      Automatic stent detection in intravascular OCT images using bagged decision trees

      Intravascular optical coherence tomography (iOCT) is being used to assess viability of new coronary artery stent designs. We developed a highly automated method for detecting stent struts and measuring tissue coverage. We trained a bagged decision trees classifier to classify candidate struts using features extracted from the images. With 12 best features identified by forward selection, recall (precision) were 90%–94% (85%–90%). Including struts deemed insufficiently bright for manual analysis, precision improved to 94%. Strut detection statistics approached variability of manual analysis. Differences between manual and automatic area measurements were 0.12 ± 0.20 mm 2 and 0.11 ...

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    8. Measuring hemodynamics in the developing heart tube with four-dimensional gated Doppler optical coherence tomography

      Measuring hemodynamics in the developing heart tube with four-dimensional gated Doppler optical coherence tomography

      Hemodynamics is thought to play a major role in heart development, yet tools to quantitatively assess hemodynamics in the embryo are sorely lacking. The especially challenging analysis of hemodynamics in the early embryo requires new technology. Small changes in blood flow could indicate when anomalies are initiated even before structural changes can be detected. Furthermore, small changes in the early embryo that affect blood flow could lead to profound abnormalities at later stages. We present a demonstration of 4-D Doppler optical coherence tomography (OCT) imaging of structure and flow, and present several new hemodynamic measurements on embryonic avian hearts at ...

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    9. Semiautomatic segmentation and quantification of calcified plaques in intracoronary optical coherence tomography images

      Semiautomatic segmentation and quantification of calcified plaques in intracoronary optical coherence tomography images
      Coronary calcified plaque (CP) is both an important marker of atherosclerosis and major determinant of the success of coronary stenting. Intracoronary optical coherence tomography (OCT) with high spatial resolution can provide detailed volumetric characterization of CP. We present a semiautomatic method for segmentation and quantification of CP in OCT images. Following segmentation of the lumen, guide wire, and arterial wall, the CP was localized by edge detection and traced using a combined intensity and gradient-based level-set model. From the segmentation regions, quantification of the depth, area, angle fill fraction, and thickness of the CP was demonstrated. Validation by comparing the ...
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    10. Imaging algorithm visualizes early heart abnormalities

      Imaging algorithm visualizes early heart abnormalities
      Combining a post-acquisition rearrangement procedure with optical coherence tomography can provide high temporal resolution for capturing subtle dynamics in the early avian embryonic heart. ying abnormalities that occur during early cardiac development is very important for understanding congenital heart defects. Optical coherence tomography (OCT) is a noninvasive imaging modality based on low-coherence interferometry that is capable of micrometer-scale resolution and 1–2mm of depth penetration in embryonic tissue. OCT can visualize and quantify real-time heart dynamics in 3D, making it a useful tool for assessing cardiac development. Real-time volume imaging performed with current systems, however, does not provide the necessary ...
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    11. High temporal resolution OCT using image-based retrospective gating

      High temporal resolution OCT using image-based retrospective gating
      High temporal resolution OCT imaging is very advantageous for analyzing cardiac mechanics in the developing embryonic heart of small animals. An image-based retrospective gating technique is presented to increase the effective temporal resolution of an OCT system and to allow visualization of systolic dynamics in 3D. The gating technique employs image similarity measures for rearranging asynchronously acquired input data consisting of a time series of 2D images at each z position along the heart volume, to produce a time sequence of 3D volumes of the beating heart. The study includes a novel robust validation technique, which quantitatively evaluates the accuracy ...
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    1-12 of 12
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    1. (12 articles) Case Western Reserve University
    2. (12 articles) Madhusudhana Gargesha
    3. (11 articles) David L. Wilson
    4. (9 articles) Andrew M. Rollins
    5. (8 articles) Hiram G. Bezerra
    6. (7 articles) Marco A. Costa
    7. (4 articles) Michael W. Jenkins
    8. (3 articles) Yusuke Fujino
    9. (3 articles) Zhao Wang
    10. (3 articles) Guilherme F. Attizzani
    11. (1 articles) Harvard University
    12. (1 articles) Massachusetts General Hospital
    13. (1 articles) Delft University of Technology
    14. (1 articles) Chinese Academy of Sciences
    15. (1 articles) Robert A. Huber
    16. (1 articles) Gijs van Soest
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    High temporal resolution OCT using image-based retrospective gating Imaging algorithm visualizes early heart abnormalities Semiautomatic segmentation and quantification of calcified plaques in intracoronary optical coherence tomography images Measuring hemodynamics in the developing heart tube with four-dimensional gated Doppler optical coherence tomography Automatic stent detection in intravascular OCT images using bagged decision trees Feature Of The Week 1/20/13: CWRU Demonstrates Automatic Stent Detection in Intravascular OCT Images Using Bagged Decision Trees Volumetric Characterization of Human Coronary Calcification by Frequency-Domain Optical Coherence Tomography. Parameter estimation of atherosclerotic tissue optical properties from three-dimensional intravascular optical coherence tomography 3D registration of intravascular optical coherence tomography and cryo-image volumes for microscopic-resolution validation AI-Assisted In Situ Detection of Human Glioma Infiltration Using a Novel Computational Method for Optical Coherence Tomography Motorized capsule for shadow-free OCT imaging and synchronous beam control Notal Vision Diagnostic Clinic reports completion of 6 million ForeseeHome AMD home-monitoring tests