1. Articles in category: Gastroenterology

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    1. NIR-II dual-modal optical coherence tomography and photoacoustic imaging-guided dose-control cancer chemotherapy

      NIR-II dual-modal optical coherence tomography and photoacoustic imaging-guided dose-control cancer chemotherapy

      In this study, an organic nano-drug delivery platform was constructed as a biocompatible cancer chemotherapeutic system, in which clini-cally approved sorafenib was loaded in the redox-responsive polymeric micelles, enabling dose-control release of drug to cancer tissues. In addition, visualizing tumor microenvironment changes is also essential for cancer chemotherapy, which can provide a priori and feedback control of drug delivery with reduced side effect. Therefore, second near-infrared window (NIR-II) dual-modal optical coherence tomogra-phy (OCT) and photoacoustic imaging were performed for real-time visualizing tumor microenvironment changes in vivo during chemo-therapy. In particular, the tumor angiogenesis, the vascular networks density change, and the ...

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    2. 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 2020 NIH Grant for $683,687 for Microvasculature in Colon Field Carcinogenesis: Clinical-Biological Implications. The principal investigator is Hemat Roy. 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 the clinical/biological implications of mucosal early increase in ...

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    3. Beating Cancer - One Patient at a Time

      Beating Cancer - One Patient at a Time

      Like most people, John Gifford wasn't looking forward to a colonoscopy when he arrived on the UCI Medical Center campus in Orange in 2018. The Riverside man, 65, was concerned about his family history of colorectal cancer and had dutifully scheduled an appointment with UCI Health gastroenterologist Dr. William Karnes. The exam turned out to be intriguing and enlightening - a far cry from what one expects during a colonoscopy, Gifford recalls with a laugh.

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    4. Capsule Endomicroscopy for Visualization of the Small Intestine in EED Population in Pakistan

      Capsule Endomicroscopy for Visualization of the Small Intestine in EED Population in Pakistan

      The laboratory has developed a minimally invasive screening method known as tethered capsule endomicroscopy (TCE) for imaging intestinal mucosa. With TCE, an unsedated subject swallows a tethered pill, which captures microscopic images of the entire esophagus, stomach, and small intestine, as it is naturally transits these organs via peristalsis and under the influence of gravity. The capsule implements a microscopic imaging technology called optical coherence tomography (OCT) that obtains 10-µm-resolution cross-sectional images of tissue. The procedure is brief, well tolerated, and can be much less expensive than endoscopy. The Investigators have implemented TCE for imaging the upper gastrointestinal tract ...

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    5. Steerable OCT catheter for real-time assistance during teleoperated endoscopic treatment of colorectal cancer

      Steerable OCT catheter for real-time assistance during teleoperated endoscopic treatment of colorectal cancer

      When detected early, colorectal cancer can be treated with minimally invasive flexible endoscopy. However, since only specialized experts can delineate margins and perform endoscopic resections of lesions, patients still often undergo colon resections. To better assist in the performance of surgical tasks, a robotized flexible interventional endoscope was previously developed, having two additional side channels for surgical instrument. We propose to enhance the imaging capabilities of this device by combining it with optical coherence tomography (OCT). For this purpose, we have developed a new steerable OCT instrument with an outer diameter of 3.5 mm. The steerable instrument is terminated ...

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    6. Massachusetts General Hospital Receives NIH Grant for A Tethered Capsule Endoscopic-Endomicroscopic (TEEM) Approach for Improving Upper GI Tract Diagnosis

      Massachusetts General Hospital Receives NIH Grant for A Tethered Capsule Endoscopic-Endomicroscopic (TEEM) Approach for Improving Upper GI Tract Diagnosis

      Massachusetts General Hospital Receives a 2020 NIH Grant for $627,739 for A Tethered Capsule Endoscopic-Endomicroscopic (TEEM) Approach for Improving Upper GI Tract Diagnosis. The principal investigator is Guillermo Tearney. Below is a summary of the proposed work. The diagnosis of most upper GI tract conditions is currently accomplished by upper endoscopy with biopsy (EGD). EGD is costly primarily because it requires conscious sedation, necessitating that procedures be conducted by physicians in a specialized endoscopy suite, and that patients take time away from work and family. Another limitation is sampling error - endoscopic biopsies are frequently random, resulting in many instances ...

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    7. Automatic vessel lumen segmentation in optical coherence tomography (OCT) images

      Automatic vessel lumen segmentation in optical coherence tomography (OCT) images

      This paper presents a graph based method to automatically and accurately segment the lumen borders from optical coherence tomography (OCT) images. The proposed method unravels the OCT images from the Cartesian coordinates to polar coordinates so that the segmentation is transferred into a height field delineation problem. In effect, the method imposes a simplistic star shape prior but without the bias towards narrower lumen size. The lumen border is identified as the solution to finding the minimum closed set on a node-weighed, directed graph. In order to cope with both the variability in imaging condition and different forms of image ...

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    8. Duke University School Receives NIH Grant for Advanced A/LCI systems for Improved Clinical Utility

      Duke University School Receives NIH Grant for Advanced A/LCI systems for Improved Clinical Utility

      Duke University School Receives a 2019 NIH Grant for $436,303 for Advanced A/LCI systems for Improved Clinical Utility. The principal investigator is Adam Wax. Below is a summary of the proposed work. There is a critical unmet need for in vivo detection of dysplasia in patients with Barrett's esophagus (BE), a neoplastic tissue state resulting from chronic acid reflux. BE is associated with an increased risk of esophageal cancer, a disease with a high morbidity rate. Patients with BE undergo periodic endoscopic surveillance with systematic biopsy to search for pre-cancerous, dysplastic tissues, at which point therapeutic treatment ...

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    9. Deep-Learning System Detects Neoplasia in Patients With Barrett’s Esophagus With Higher Accuracy Than Endoscopists in a Multi-Step Training and Validation Study with Benchmarking

      Deep-Learning System Detects Neoplasia in Patients With Barrett’s Esophagus With Higher Accuracy Than Endoscopists in a Multi-Step Training and Validation Study with Benchmarking

      Background & Aims We aimed to develop and validate a deep-learning computer-aided detection (CAD) system, suitable for use in real time in clinical practice, to improve endoscopic detection of early neoplasia in patients with Barrett’s esophagus (BE). Methods We developed a hybrid ResNet-UNet model CAD system using 5 independent endoscopy datasets. We performed pre-training using 494,364 labelled endoscopic images collected from all intestinal segments. Then, we used 1704 unique esophageal high-resolution images of rigorously confirmed early-stage neoplasia from patients with BE, and non-dysplastic BE, derived from 669 patients. System performance was assessed using datasets 4 and 5. Dataset 5 ...

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    10. Machine learning, imaging technique may boost colon cancer diagnosis

      Machine learning, imaging technique may boost colon cancer diagnosis

      Colorectal cancer is the second most common type of cancer worldwide, with about 90% of cases occurring in people 50 or older. Arising from the inner surface, or muscosal layer, of the colon, cancerous cells can penetrate through the deeper layers of the colon and spread to other organs. Left untreated, the disease is fatal. Current colon cancer screening is performed by flexible colonoscopy. The procedure involves visual inspection of the mucosal lining of the colon and rectum with a camera mounted on an endoscope. Abnormal appearing areas are then biopsied for analysis. Although this is the current standard of ...

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    11. 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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    12. 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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    13. 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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    14. 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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    15. 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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    16. 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
    17. 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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    18. 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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    19. 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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    20. 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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    21. 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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    22. 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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    23. 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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    24. 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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