1. Articles in category: Gastroenterology

    1-24 of 608 1 2 3 4 ... 24 25 26 »
    1. Comparison of optical coherence tomography angiography and narrow-band imaging using a bimodal endoscope

      Comparison of optical coherence tomography angiography and narrow-band imaging using a bimodal endoscope

      We present coregistered images of tissue vasculature that allow a direct comparison between the performance of narrow-band imaging (NBI) and optical coherence tomography angiography (OCTA). Images were generated with a bimodal endomicroscope having a size of 15  ×  2.4  ×  3.3  mm 3   (   l   ,   w   ,   h   )   that combines two imaging channels. The white light imaging channel was used to perform NBI, the current gold standard for endoscopic visualization of vessels. The second channel allowed the simultaneous acquisition of optical coherence tomography (OCT) and OCTA images, enabling a three-dimensional (3-D) visualization of morphological as well as functional tissue information. In order ...

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    2. Volumetric laser endomicroscopy and optical coherence tomography in Barrett’s esophagus: a systematic review and meta-analysis

      Volumetric laser endomicroscopy and optical coherence tomography in Barrett’s esophagus: a systematic review and meta-analysis

      Background and study aims Endoscopic imaging of Barrett’s esophagus (BE) with advanced technologies, such as optical coherence tomography (OCT) and volumetric laser endomicroscopy (VLE), allows targeted biopsies and may reduce the number of random biopsies to detect esophageal neoplasia in the early stages during endoscopic BE surveillance. The aim of this study was to evaluate the accuracy of OCT and VLE in diagnosis of intestinal metaplasia, dysplasia, and high-grade dysplasia (HGD), and intramucosal carcinoma (IMC) in BE. Patients and methods In this systematic review and meta-analysis, the primary outcome measure was diagnostic accuracy of OCT and VLE, in comparison ...

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    3. Classification of human stomach cancer using morphological feature analysis from optical coherence tomography images

      Classification of human stomach cancer using morphological feature analysis from optical coherence tomography images

      Optical coherence tomography is radiation-free, and it is considered a tool of optical biopsy. Classification of normal and cancerous tissues is very important for the guidance of surgeons. Here, we develop the morphological feature analysis-based classification (MFAC) method, combining it with machine learning to identify cancerous tissues. We extract five quantitative morphological features from one OCT image through the structured analysis. Five classifiers are involved to make a classification: the support vector machine, the K -nearest neighbor, the random forest, logic regression, and the conventional threshold method. Sensitivity, specificity, and accuracy are used to evaluate these classifiers and are compared ...

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    4. Optical Coherence Tomography/Fluorescence Imaging: Fiber assembly enables efficient multimodal endoscopy

      Optical Coherence Tomography/Fluorescence Imaging: Fiber assembly enables efficient multimodal endoscopy

      While optical coherence tomography (OCT) provides structural contrast with a resolution on the order of tens of microns, for some applications this information is, in some contexts, insufficient to provide a definitive diagnostic. To mitigate this limitation, OCT has been used in conjunction with fluorescence imaging or spectroscopy for detection of molecular content in tissues. The combination of OCT and fluorescence has been used for a variety of applications, most notably to study atherosclerotic plaque in cardiology, 1 to visualize the fine vascular network in pulmonology (for which autofluorescence is used), 2 and for cancer imaging. 3

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    5. NinePoint Medical Announces FDA Clearance for Pancreatic and Biliary Applications of the NvisionVLE® Imaging System

      NinePoint Medical Announces FDA Clearance for Pancreatic and Biliary Applications of the NvisionVLE® Imaging System

      NinePoint Medical, Inc ., a transformative medical device company pioneering the use of a real-time optical imaging platform for gastrointestinal applications, announced today that it has received U.S. Food and Drug Administration (FDA) clearance to market the NvisionVLE® Imaging System for use in the pancreas and bile duct. These anatomical indications add to the previously existing esophageal applications for NinePoint’s state-of-the-art Optical Coherence Tomography (OCT) imaging platform. The NvisionVLE Imaging System provides physicians real-time, high-resolution volumetric images of the tissue surface and subsurface. This allows gastroenterologists to thoroughly evaluate tissue for regions of interest that may not be visible ...

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    6. Application of OCT in the Gastrointestinal Tract

      Application of OCT in the Gastrointestinal Tract

      Optical coherence tomography (OCT) is uniquely poised for advanced imaging in the gastrointestinal (GI) tract as it allows real-time, subsurface and wide-field evaluation at near-microscopic resolution, which may improve the current limitations or even obviate the need of superficial random biopsies in the surveillance of early neoplasias in the near future. OCT’s greatest impact so far in the GI tract has been in the study of the tubular esophagus owing to its accessibility, less bends and folds and allowance of balloon employment with optimal contact to aid circumferential imaging. Moreover, given the alarming rise in the incidence of Barrett ...

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      Mentions: Hiroshi Mashimo
    7. Motorized capsule for shadow-free OCT imaging and synchronous beam control

      Motorized capsule for shadow-free OCT imaging and synchronous beam control

      We demonstrate a tethered motorized capsule for unobstructed optical coherence tomography (OCT) imaging of the esophagus. By using a distal reflector design, we avoided the common shadow artifact induced by the motor wires. A synchronous driving technique features three types of beam-scanning modes of the capsule, i.e., circumferential beam scanning, localized beam scanning, and accurate beam positioning. We characterized these three modes and carried out ex vivo imaging experiments using the capsule. The results show that the capsule can potentially be a useful tool for diagnostic OCT imaging and OCT-guided biopsy and therapy of the esophagus.

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    8. A Micro Pill Camera Captures Images in Cancer Screening

      A Micro Pill Camera Captures Images in Cancer Screening

      Getting histologic images of the esophagus and other parts of the digestive tract may soon be as easy as getting patients to swallow pill-sized cameras. Called tethered capsule endomicroscopy (TCE), the technology can take multiple microscope images and it shows promise for diagnosing and monitoring Barrett's esophagus. The cameras allow for getting real-time histological images of tissue without requiring anesthesia or endoscopy in what some researchers are referring to as optical or digital tissue biopsy. TCE cameras were initially developed at The Tearney Lab at Massachusetts General Hospital and prototypes of several versions are under development. TCE is also ...

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    9. Rapid, High-Resolution, Label-Free, and 3-Dimensional Imaging to Differentiate Colorectal Adenomas and Non-Neoplastic Polyps With Micro-Optical Coherence Tomography

      Rapid, High-Resolution, Label-Free, and 3-Dimensional Imaging to Differentiate Colorectal Adenomas and Non-Neoplastic Polyps With Micro-Optical Coherence Tomography

      INTRODUCTION: “ Resectanddiscard ” paradigmisoneofthemainstrategiestodealwithcolorectaldiminutivepolyps after optical diagnosis. However, there are risks that unrecognized potentially malignant lesions are discarded without accurate diagnosis. The purpose of this study is to validate the potential of micro- optical coherence tomography ( m OCT) to improve the diagnostic accuracy of colorectal lesions and help endoscopists make better clinical decision without additional pathology costs. METHODS: RESULTS: DISCUSSION: Fresh tissue samples were obtained from patients with colorectal polyps or colorectal cancer who received endoscopic therapy or laparoscopic surgery. These samples were instantly imaged by m OCT and then sent to pathological evaluation. Then, m OCT images were compared with ...

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    10. Optical coherence tomography to detect acute esophageal radiation-induced damage in mice: a validation study

      Optical coherence tomography to detect acute esophageal radiation-induced damage in mice: a validation study

      Radiation therapy for patients with non-small-cell lung cancer is hampered by acute radiation-induced toxicity in the esophagus. This study aims to validate that optical coherence tomography (OCT), a minimally invasive imaging technique with high resolution (~10 µm), is able to visualize and monitor acute radiation-induced esophageal damage (ARIED) in mice. We compare our findings with histopathology as the gold standard. Irradiated mice receive a single dose of 40 Gy at proximal and distal spots of the esophagus of 10.0 mm in diameter. We scan mice using OCT at two, three, and seven days post-irradiation. In OCT analysis we define ...

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    11. NinePoint Medical Announces Publication of 1000 Patient Registry Study

      NinePoint Medical Announces Publication of 1000 Patient Registry Study

      NinePoint Medical, Inc, a transformative medical device company pioneering the use of Optical Coherence Tomography (OCT) for gastrointestinal applications, today announced the publication of their 1000 patient Volumetric Laser Endomicroscopy (VLE) Registry study focused on Barrett’s Esophagus. The 18 site study, published in Diseases of the Esophagus , enrolled 1000 patients between 2014 and 2016 for imaging using the NvisionVLE® Imaging System. The study was designed to determine usage patterns of VLE in clinical practice and to estimate quantitative and qualitative performance metrics, with this publication focused on Barrett’s Esophagus. All enrolled patients were examined with standard upper endoscopy ...

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    12. Volumetric laser endomicroscopy and its application to Barrett's esophagus: results from a 1,000 patient registry

      Volumetric laser endomicroscopy and its application to Barrett's esophagus: results from a 1,000 patient registry

      Volumetric laser endomicroscopy (VLE) uses optical coherence tomography (OCT) for real-time, microscopic cross-sectional imaging. A US-based multi-center registry was constructed to prospectively collect data on patients undergoing upper endoscopy during which a VLE scan was performed. The objective of this registry was to determine usage patterns of VLE in clinical practice and to estimate quantitative and qualitative performance metrics as they are applied to Barrett's esophagus (BE) management. All procedures utilized the NvisionVLE Imaging System (NinePoint Medical, Bedford, MA) which was used by investigators to identify the tissue types present, along with focal areas of concern. Following the VLE ...

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    13. Multimodal endoscopy for colorectal cancer detection by optical coherence tomography and near-infrared fluorescence imaging

      Multimodal endoscopy for colorectal cancer detection by optical coherence tomography and near-infrared fluorescence imaging

      While colonoscopy is the gold standard for diagnosis and classification of colorectal cancer (CRC), its sensitivity and specificity are operator-dependent and are especially poor for small and flat lesions. Contemporary imaging modalities, such as optical coherence tomography (OCT) and near-infrared (NIR) fluorescence, have been investigated to visualize microvasculature and morphological changes for detecting early stage CRC in the gastrointestinal (GI) tract. In our study, we developed a multimodal endoscopic system with simultaneous co-registered OCT and NIR fluorescence imaging. By introducing a contrast agent into the vascular network, NIR fluorescence is able to highlight the cancer-suspected area based on significant change ...

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    14. Balloon catheter-based radiofrequency ablation monitoring in porcine esophagus using optical coherence tomography

      Balloon catheter-based radiofrequency ablation monitoring in porcine esophagus using optical coherence tomography

      We present a microscopic image guidance platform for radiofrequency ablation (RFA) using a clinical balloon-catheter-based optical coherence tomography (OCT) system, currently used in the surveillance of Barrett’s esophagus patients. Our integrated thermal therapy delivery and monitoring platform consists of a flexible, customized bipolar RFA electrode array designed for use with a clinical balloon OCT catheter and a processing algorithm to accurately map the thermal coagulation process. Non-uniform rotation distortion was corrected using a feature tracking-based technique, which enables robust, frame-to-frame analysis of the temporal fluctuation of the complex OCT signal. With proper noise calibration, precise delineation of the thermal ...

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    15. A new step for volumetric laser endomicroscopy: entering the therapeutic realm of endoscopic mucosal resection

      A new step for volumetric laser endomicroscopy: entering the therapeutic realm of endoscopic mucosal resection

      The incidence of esophageal adenocarcinoma (EAC) is rising despite a better understanding of the natural history of Barrett’s esophagus (BE) as a precursor lesion for EAC. 1 Surveillance is recommended once the diagnosis of BE is established, and endoscopic eradication therapy is reserved for treatment of dysplasia or early neoplasia. 2 In recent years, significant clinical and technologic advances have been made in endoscopic methods for the diagnosis and treatment of early esophageal adenocarcinomas arising in Barrett’s esophagus. 3 , 4 , 5 In the current issue of Gastrointestinal Endoscopy , Kamboj et al 6 show that using a synergistic combination ...

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    16. FULL-FIELD OPTICAL COHERENCE TOMOGRAPHY OF THE NORMAL DIGESTIVE MUCOSA: A PROMISING TOOL FOR THE STUDY OF THE DIGESTIVE BARRIER

      FULL-FIELD OPTICAL COHERENCE TOMOGRAPHY OF THE NORMAL DIGESTIVE MUCOSA: A PROMISING TOOL FOR THE STUDY OF THE DIGESTIVE BARRIER

      Aims: Full-field optical coherence tomography (FF-OCT) is a non-invasive imaging technique, based on interferometry, allowing dynamic acquisition of images of ex vivo specimens on a microscopic scale. The aim of this study was to demonstrate the feasibility of imaging normal digestive biopsies using FF-OCT. Methods: We enrolled adult subjects scheduled for an endoscopy with biopsies, who had no history of digestive disease. We a posteriori excluded patients, whose biopsies showed abnormal aspects at pathological examination. Four biopsies were sampled in each patient, 2 for pathological examination, 2 for immediate FF-OCT analysis, from 5 different locations: esophagus, gastric antrum, gastric fundus ...

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    17. NinePoint Medical Receives NIH Grant for An Integrated Optical Coherence Tomography and Tissue Acquisition Device for Diagnostics of Indeterminate Biliary Strictures

      NinePoint Medical Receives NIH Grant for An Integrated Optical Coherence Tomography and Tissue Acquisition Device for Diagnostics of Indeterminate Biliary Strictures

      NinePoint Medical Receives a 2019 NIH Grant for $222,020 for An Integrated Optical Coherence Tomography and Tissue Acquisition Device for Diagnostics of Indeterminate Biliary Strictures. The principal investigator is Eman Namati. The program began in 2019 and ends in 2020. Below is a summary of the proposed work. Bile duct strictures can lead to painful clinical symptoms and can be caused by a wide range of conditions from benign diseases to cholangiocarcinoma, a deadly cancer of the bile duct with 5-year survival rates as low as 2% for late stage disease. The management and prognosis of bile duct strictures ...

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    18. Boston Medical Center Receives NIH Grant for Microvasculature in Colon Field Carcinogenesis: Clinical-Biological Implications

      Boston Medical Center Receives NIH Grant for Microvasculature in Colon Field Carcinogenesis: Clinical-Biological Implications

      Boston Medical Center Receives a 2019 NIH Grant for $669,582 for Microvasculature in Colon Field Carcinogenesis: Clinical-Biological Implications. The principal investigator is Hemat Roy. The program began in 2018 and ends in 2023. Below is a summary of the proposed work. The overall goal of this project is to develop a rectal probe for minimally intrusive highly accurate risk stratification with the vision of utilizing it for a precision medicine approach to colon cancer screening and also potentially chemoprevention (companion biomarker). We will employ cutting edge biophotonics (ISOCT) and biological approaches combined with large scale human studies to elucidate ...

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    19. 10 Breakthrough Technologies 2019

      10 Breakthrough Technologies 2019

      A small, swallowable device captures detailed images of the gut without anesthesia, even in infants and children. Environmental enteric dysfunction (EED) may be one of the costliest diseases you’ve never heard of. Marked by inflamed intestines that are leaky and absorb nutrients poorly, it’s widespread in poor countries and is one reason why many people there are malnourished, have developmental delays, and never reach a normal height. No one knows exactly what causes EED and how it could be prevented or treated. Practical screening to detect it would help medical workers know when to intervene and how. Therapies ...

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    20. Optical coherence tomography-guided laser marking with tethered capsule endomicroscopy in unsedated patients

      Optical coherence tomography-guided laser marking with tethered capsule endomicroscopy in unsedated patients

      Tethered capsule endomicroscopy (TCE) is an emerging screening technology that comprehensively obtains microstructural OCT images of the gastrointestinal (GI) tract in unsedated patients. To advance clinical adoption of this imaging technique, it will be important to validate TCE images with co-localized histology, the current diagnostic gold standard. One method for co-localizing OCT images with histology is image-targeted laser marking, which has previously been implemented using a driveshaft-based, balloon OCT catheter, deployed during endoscopy. In this paper, we present a TCE device that scans and targets the imaging beam using a low-cost stepper motor that is integrated inside the capsule. In ...

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    21. Predict, Resect, Identify and Discard Strategy with Full-field Optical Coherence Tomography: Two Steps Forward, One Step Back

      Predict, Resect, Identify and Discard Strategy with Full-field Optical Coherence Tomography: Two Steps Forward, One Step Back

      Dear editor, We read with great interest the recently published technique presentation reported by Camus M et al.1 on a rapid on-site evaluation of resected colorectal polyps using full-field optical coherence tomography (FFOCT). We concur that this “predict, resect, identify and discard” paradigm indicated a new way of balancing colonoscopy screening efficacy and pathologic burden as well as shortening the distances among endoscopists, pathologists and patients. While nearly all resected colonic polyps are retrieved for histological analysis in America and Europe, polyp retrieval rate is suboptimal in China due to limited pathologic resources and cost-effectiveness considerations, even in some ...

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    22. Pilot Study for OCT Guided In Vivo Laser Capture Microdissection for Assessing the Prognosis of Barrett's Esophagus

      Pilot Study for OCT Guided In Vivo Laser Capture Microdissection for Assessing the Prognosis of Barrett's Esophagus

      The investigators have developed a new technology, termed in-vivo laser capture microdissection (IVLCM), that addresses the limitations of endoscopic biopsy for screening for BE and provides targeted genomic profiling of aberrant tissue for more precise prediction of EAC risk. The device is a tethered capsule endomicroscope (TCE) that implements optical coherence tomography (OCT) to grab 10-mm-resolution, cross-sectional microscopic images of the entire esophagus after the capsule is swallowed. This OCT-based TCE technology is used in unsedated patients to visualize images of BE and dysplastic BE. During the IVLCM procedure, TCE images of abnormal BE tissue are identified in real time ...

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    23. Integrated ultrasound, OCT, PA and/or florescence imaging endoscope for diagnosing cancers in gastrointestinal, respiratory, and urogenital tracts

      Integrated ultrasound, OCT, PA and/or florescence imaging endoscope for diagnosing cancers in gastrointestinal, respiratory, and urogenital tracts

      A multimodality imaging system including ultrasound, optical coherence tomography (OCT), photoacoustic (PA) imaging, florescence imaging and endoscopic catheter for imaging inside the gastrointestinal tract with real-time automatic image co-registration capability, including: an ultrasound subsystem for imaging; an optical coherence tomography (OCT) subsystem for imaging, a PA microscopy or tomography subsystem for imaging and a florescence imaging subsystem for imaging. An invasive interventional imaging device is included with an instrumentality to take a tissue biopsy from a location visible on the ultrasound subsystem for imaging, on the optical coherence tomography (OCT) subsystem for imaging, photoacoustic (PA) subsystem for imaging and florescence ...

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    24. Measuring Barrett’s Epithelial Thickness with Volumetric Laser Endomicroscopy as a Biomarker to Guide Treatment

      Measuring Barrett’s Epithelial Thickness with Volumetric Laser Endomicroscopy as a Biomarker to Guide Treatment

      Background Radiofrequency ablation (RFA) treatment outcomes vary for unknown reasons. One hypothesis is that variations in Barrett’s epithelial thickness (BET) are associated with reduced RFA efficacy for thicker BET and strictures for thinner BET. Volumetric laser endomicroscopy (VLE) is an imaging modality that acquires high-resolution, depth-resolved images of BE. However, the attenuation of light by tissue and the lack of layering in Barrett’s tissue challenge BET measurements and the study of relationships between thickness and RFA outcomes. We aimed to quantify BET and compared the reliability of standard and contrast-enhanced VLE images. Methods Baseline VLE scans from BE ...

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