1. Articles in category: Gastroenterology

    1-24 of 641 1 2 3 4 ... 25 26 27 »
    1. Advanced endoscopic imaging for detecting and guiding therapy of early neoplasias of the esophagus

      Advanced endoscopic imaging for detecting and guiding therapy of early neoplasias of the esophagus

      Esophageal cancers, largely adenocarcinoma in Western countries and squamous cell cancer in Asia, present a significant burden of disease and remain one of the most lethal of cancers. Key to improving survival is the development and adoption of new imaging modalities to identify early neoplastic lesions, which may be small, multifocal, subsurface, and difficult to detect by standard endoscopy. Such advanced imaging is particularly relevant with the emergence of ablative techniques that often require multiple endoscopic sessions and may be complicated by bleeding, pain, strictures, and recurrences. Assessing the specific location, depth of involvement, and features correlated with neoplastic progression ...

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    2. Visualization of Bacterial Colonization and Cellular Layers in a Gut-on-a-Chip System Using Optical Coherence Tomography

      Visualization of Bacterial Colonization and Cellular Layers in a Gut-on-a-Chip System Using Optical Coherence Tomography

      Imaging of cellular layers in a gut-on-a-chip system has been confined to two-dimensional (2D)-imaging through conventional light microscopy and confocal laser scanning microscopy (CLSM) yielding three-dimensional- and 2D-cross-sectional reconstructions. However, CLSM requires staining and is unsuitable for longitudinal visualization. Here, we compare merits of optical coherence tomography (OCT) with those of CLSM and light microscopy for visualization of intestinal epithelial layers during protection by a probiotic Bifidobacterium breve strain and a simultaneous pathogen challenge by an Escherichia coli strain. OCT cross-sectional images yielded film thicknesses that coincided with end-point thicknesses derived from cross-sectional CLSM images. Light microscopy on histological ...

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    3. Endoscopic imaging in inflammatory bowel disease: current developments and emerging strategies

      Endoscopic imaging in inflammatory bowel disease: current developments and emerging strategies

      Developments in enhanced and magnified endoscopy have signified major advances in endoscopic imaging of ileocolonic pathology in inflammatory bowel disease (IBD). Artificial intelligence is increasingly being used to augment the benefits of these advanced techniques. Nevertheless, treatment of IBD patients is frustrated by high rates of non-response to therapy, while delayed detection and failures to detect neoplastic lesions impede successful surveillance. A possible solution is offered by molecular imaging, which adds functional imaging data to mucosal morphology assessment through visualizing biological parameters. Other label-free modalities enable visualization beyond the mucosal surface without the need of tracers.

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    4. Study of Gastrointestinal Dysfunction and Enteric Neural Pathology in Patients With Parkinson's Disease

      Study of Gastrointestinal Dysfunction and Enteric Neural Pathology in Patients With Parkinson's Disease

      The purpose of this study is to establish the esophageal pathology findings as imaged with tethered capsule microscopy in subjects with Parkinson Disease. Images from patients with Parkinson disease will be compared to our previously obtained images in healthy subjects to establish the spectrum of esophageal pathologies occurring in patients with Parkinson disease by OCT imaging. In the case of imaging internal luminal organs, like the esophagus, OCT light is delivered via a long catheter. We have developed a new technique termed Tethered Capsule Endomicroscopy (TCE). TCE involves swallowing a tethered capsule that acquires cross-sectional microscopic images of the entire ...

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    5. Optical Imaging of Gastrointestinal Biopsy Samples and Their Correlation With Histology

      Optical Imaging of Gastrointestinal Biopsy Samples and Their Correlation With Histology

      The investigators have previously developed optical imaging systems that have been able to provide highly detailed images of tissue structures in multiple application areas including Cardiology, Gastroenterology, and Pulmonology. They are looking to continue the advancement of these various technologies under development. The population will include subjects who are undergoing elective esophagogastroduodenoscopy with biopsy, colonoscopy with biopsy, and/or endo-mucosal resection.The endoscopist will take no more than 3 biopsies in addition to the standard of care biopsies. The study will be optical imaging of the ex vivo GI specimens that are being collected. Specimens will be collected for research ...

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    6. Evaluation of Tethered Capsule Endomicroscopy as a Screening Tool for Barrett's Esophagus in the Primary Care Setting

      Evaluation of Tethered Capsule Endomicroscopy as a Screening Tool for Barrett's Esophagus in the Primary Care Setting

      The investigators have developed a tethered capsule OCT device intended as an inexpensive screening tool for BE. The capsule, which is attached to a thin, flexible tether, is reusable after being processed by a standard disinfection technique. Used without sedation, the capsule is swallowed by the participant and travels in the esophagus to the gastroesophageal junction (GEJ) via peristalsis. Cross-sectional microscopic OCT images of the entire esophagus are collected during transit. The total time needed for swallowing, imaging and retrieval does not exceed 10 minutes, with a total of 30 minutes for the procedure. The investigators have tested the feasibility ...

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    7. Tethered capsule en face optical coherence tomography for imaging Barrett’s oesophagus in unsedated patients

      Tethered capsule en face optical coherence tomography for imaging Barrett’s oesophagus in unsedated patients

      Objective Barrett’s oesophagus (BE) screening outside the endoscopy suite can identify patients for surveillance and reduce mortality. Tethered capsule optical coherence tomography (OCT) can volumetrically image oesophageal mucosa in unsedated patients and detect features of BE. We investigated ultrahigh-speed tethered capsule swept-source OCT (SS-OCT), improved device design, developed procedural techniques and measured capsule contact, longitudinal pullback non-uniformity and patient toleration. Design OCT was performed in 16 patients prior to endoscopic surveillance/treatment. Unsedated patients swallowed the capsule with sips of water and the tether was pulled back to image the oesophagus. SS-OCT at 1 000 000 A-scans/s enabled ...

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    8. Comparison of Optical Imaging Techniques to Quantitatively Assess the Perfusion of the Gastric Conduit during Oesophagectomy

      Comparison of Optical Imaging Techniques to Quantitatively Assess the Perfusion of the Gastric Conduit during Oesophagectomy

      In this study, four optical techniques—Optical Coherence Tomography, Sidestream Darkfield Microscopy, Laser Speckle Contrast Imaging, and Fluorescence Angiography (FA)—were compared on performing an intraoperative quantitative perfusion assessment of the gastric conduit during oesophagectomy. We hypothesised that the quantitative parameters show decreased perfusion towards the fundus in the gastric conduit and in patients with anastomotic leakage. In a prospective study in patients undergoing oesophagectomy with gastric conduit reconstruction, measurements were taken with all four optical techniques at four locations from the base towards the fundus in the gastric conduit (Loc1, Loc2, Loc3, Loc4). The primary outcome included 14 quantitative ...

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    9. Massachusetts General Hospital Receives NIH Grant for Less Invasive Assessment of Inflammation and Subepithelial Remodeling in Eosinophlic Esophagitis Patients

      Massachusetts General Hospital Receives NIH Grant for Less Invasive Assessment of Inflammation and Subepithelial Remodeling in Eosinophlic Esophagitis Patients

      Massachusetts General Hospital Receives a 2020 NIH Grant for $683,034 for Less Invasive Assessment of Inflammation and Subepithelial Remodeling in Eosinophlic Esophagitis Patients. The principal investigator is Guillermo Tearney. Below is a summary of the proposed work. Eosinophilic esophagitis (EoE) is a prevalent allergic response to food that causes eosinophilic infiltration in the esophagus. EoE can lead to esophageal remodeling, scarring, muscle hypertrophy, and stricture, decreasing quality of life and increasing risk of food impaction. Diagnosis of EoE is made by finding epithelial esophageal eosinophilia in biopsies acquired during upper endoscopy. Patients are treated with topical corticosteroids or dietary ...

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    10. A detailed comparison between the endoscopic images using blue laser imaging and three-dimensional reconstructed pathological images of colonic lesions

      A detailed comparison between the endoscopic images using blue laser imaging and three-dimensional reconstructed pathological images of colonic lesions

      Blue laser/light imaging (BLI) is an image-enhanced endoscopy (IEE) technique that can provide an accurate diagnosis by closely observing the surface structure of various colonic lesions. However, complete correspondence between endoscopic images and pathological images has not been demonstrated. The aim of this study was to accurately compare endoscopic images and the pathological images using a three-dimensionally (3D) reconstructed pathological model. Continuous thin layer sections were prepared from colonic tissue specimens and immunohistochemically stained for CD34 and CAM5.2. Three-dimensional reconstructed images were created by superimposing immunohistochemically stained pathological images. The endoscopic image with magnifying BLI was compared with ...

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    11. Optical coherence tomography imaging of excised canine apocrine gland anal sac adenocarcinoma tumors

      Optical coherence tomography imaging of excised canine apocrine gland anal sac adenocarcinoma tumors

      Optical coherence tomography (OCT) is an optical imaging modality that has been investigated for real‐time surgical margin evaluation in human breast cancer patients. Previous veterinary OCT studies have been limited to surgical margin imaging for soft tissue sarcoma (STS) tumors. To the authors knowledge, OCT has never been used to characterize or evaluate other types of neoplasia in dogs. The goal of this study was to characterize the OCT imaging appearance of apocrine gland anal sac adenocarcinoma (AGASACA) in excised ex vivo specimens from five client‐owned dogs. All excised tissue surgical margins were imaged using a clinical spectral ...

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    12. Optical coherent tomography to evaluate the degree of inflammation in a mouse model of colitis

      Optical coherent tomography to evaluate the degree of inflammation in a mouse model of colitis

      Background: There is an urgent need to develop a noninvasive imaging technique for the diagnosis of early inflammatory lesions or early and real-time microscopic assessment before selecting the most representative biopsy sites. Methods: In this study, a dextran sulfate sodium colitis model was developed, and intestinal histological damage scores measured the degree of inflammation in colitis. According to these scores, 6 parameters were designed for hematoxylin and eosin (HE) sections based on morphological changes, and 2 parameters were designed for optical coherence tomography (OCT) images to measure submucosal edema by morphological changes to evaluate inflammation degrees in the colon. Spearman ...

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    13. TRANS-SEROSAL MULTIMODAL OPTICAL COHERENCE TOMOGRAPHY FOR VISUALIZATION OF MICROSTRUCTURE AND BLOOD CIRCULATION OF THE SMALL INTESTINE WALL

      TRANS-SEROSAL MULTIMODAL OPTICAL COHERENCE TOMOGRAPHY FOR VISUALIZATION OF MICROSTRUCTURE AND BLOOD CIRCULATION OF THE SMALL INTESTINE WALL

      The aim of the study was to evaluate the performance of trans-serosal multimodal OCT (MM OCT) in in vivo detecting of changes in microstructure and blood circulation of the small intestine wall caused by arteriovenous ischemia resulted from intestine strangulation. Materials and Methods. In experiments on Wistar rats (n=22), we examined the small intestine wall in vivo using MM OCT; the access to the intestine was reached through laparotomy. The microvasculature and microstructure of the wall were studied before and after acute arteriovenous ischemia created by ligation of a small bowel segment. The results were then added with data ...

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    14. Tethered capsule en face optical coherence tomography for imaging Barrett’s esophagus in unsedated patients

      Tethered capsule en face optical coherence tomography for imaging Barrett’s esophagus in unsedated patients

      Objective Detection of Barrett’s esophagus (BE) at points of care outside the endoscopy suite may improve screening access and reduce esophageal adenocarcinoma mortality. Tethered capsule optical coherence tomography (OCT) can volumetrically image esophageal mucosa and detect BE in unsedated patients. We investigated ultrahigh-speed tethered capsule, swept-source OCT (SS-OCT) in unsedated patients, improved device design, developed procedural techniques, measured how capsule contact and longitudinal pullback non-uniformity affect coverage, and assessed patient toleration. Design OCT was performed in 16 patients prior to endoscopic surveillance/treatment. Unsedated patients swallowed the capsule with small sips of water and the esophagus imaged by retracting ...

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    15. Full-field optical coherence tomography: novel imaging technique for extemporaneous high-resolution analysis of mucosal architecture in human gut biopsies

      Full-field optical coherence tomography: novel imaging technique for extemporaneous high-resolution analysis of mucosal architecture in human gut biopsies

      Full-field optical coherence tomography (FFOCT) is an imaging technique of biological tissue based on tissue light reflectance analysis. We evaluated the feasibility of imaging fresh digestive mucosal biopsies after a quick mounting procedure (5 min) using two distinct modalities of FFOCT. In static FFOCT mode, we gained high-resolution images of general gut tissue-specific architecture, such as oesophageal papillae, gastric pits, duodenal villi and colonic crypts. In dynamic FFOCT mode, we imaged individual epithelial cells of the mucosal lining with a cellular or subcellular resolution and identified cellular components of the lamina propria. FFOCT represents a promising dye-free imaging tool for ...

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    16. a/LCI-OCT Pilot in Esophagus

      a/LCI-OCT Pilot in Esophagus

      This study will test a newly developed dual modality probe, including optical coherence tomography (OCT) and angle-resolved low-coherence interferometry (a/LCI), in the human esophagus to determine 1) whether adequate tissue contact can be attained by the probe to acquire high quality images, and 2) to identify if these images can discern whether the imaged tissue is squamous or Barrett's Esophagus (BE) epithelium. This pilot study will test the operating characteristics of the probe and collect data for further optimization of the a/LCI-OCT device.

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    17. Merit Medical Reports Earnings for Quarter Ended March 31, 2020, Withdraws FY 2020 Guidance

      Merit Medical Reports Earnings for Quarter Ended March 31, 2020, Withdraws FY 2020 Guidance

      Merit Medical Systems, Inc. (NASDAQ: MMSI), a leading manufacturer and marketer of proprietary disposable devices used in interventional, diagnostic and therapeutic procedures, particularly in cardiology, radiology, oncology, critical care and endoscopy, today announced revenue of $243.5 million for the quarter ended March 31, 2020, an increase of 2.2% over revenue of $238.3 million for the quarter ended March 31, 2019....$1.4M Represents write-off of inventory related to our distribution agreement with NinePoint Medical, Inc.

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    18. Automatic differentiation of nonkeratinized stratified squamous epithelia and columnar epithelia through feature structure extraction using OCT

      Automatic differentiation of nonkeratinized stratified squamous epithelia and columnar epithelia through feature structure extraction using OCT

      As a type of precancerous lesion, metaplasia is usually considered to be associated with developing cancer. In clinical practice, surveillance of metaplastic cases usually relies on excisional biopsy followed by histological processing and analysis. As it is an invasive method accompanied by other complications, non-invasive imaging methods such as optical coherence tomography (OCT) can complement the existing method by enabling large area scanning. However, because it takes time to review large amount of data acquired from the whole suspected mucosal areas, an automatic classification method is preferred to alleviate the laboring hours and to avoid ‘sampling errors’ during image analysis ...

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    19. Optical coherence tomography of the pancreatic and bile ducts: are we ready for prime time?

      Optical coherence tomography of the pancreatic and bile ducts: are we ready for prime time?

      Background and study aims  First-generation optical coherence tomography (OCT) has been shown to increase diagnostic sensitivity for malignant biliary and pancreatic-duct strictures. A newer OCT imaging system, NVision Volumetric Laser Endomicroscopy (VLE), allows for in vivo cross-sectional imaging of the ductal wall at the microstructure level during endoscopic retrograde cholangiopancreatography (ERCP). The aim of this study was to identify and evaluate characteristics on OCT that are predictive of benign and malignant strictures. Patients and methods  Consecutive patients from six centers who underwent OCT between September 2016 and September 2017 were included in a dedicated registry. OCT images were analyzed, and ...

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    20. NinePoint Medical Receives NIH Grant for AI Computer Aided Diagnosis (CAD) Algorithm for Identification of Dysplasia in Patients with Barrett Esophagus

      NinePoint Medical Receives NIH Grant for AI Computer Aided Diagnosis (CAD) Algorithm for Identification of Dysplasia in Patients with Barrett Esophagus

      NinePoint Medical Receives a 2020 NIH Grant for $852,440 for AI Computer Aided Diagnosis (CAD) Algorithm for Identification of dysplasia in Patients with Barrett Esophagus. The principal investigator is Eman Namati. Below is a summary of the proposed work. The goal of this project is to develop a based computer aided diagnosis (CAD) algorithm for identification of regions at risk for developing esophageal adenocarcinoma (EAC) in optical coherence tomography (OCT) scans of the esophagus. EAC is one of the deadliest cancers with a 5-year survival rate of less than 20%; yet the standard of care for detecting precursors to ...

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    21. University of Pittsburg Receives NIH Grant for Three Dimensional nanoscale Nuclear Architecture Mapping based Taxonomy of Precursor Lesions for Predicting Colorectal Cancer Risk

      University of Pittsburg Receives NIH Grant for Three Dimensional nanoscale Nuclear Architecture Mapping based Taxonomy of Precursor Lesions for Predicting Colorectal Cancer Risk

      University of Pittsburg Receives a 2020 NIH Grant for $437,317 for Three Dimensional nanoscale Nuclear Architecture Mapping based Taxonomy of Precursor Lesions for Predicting Colorectal Cancer Risk. The principal investigator is Yang Liu. Below is a summary of the proposed work. The effectiveness of colorectal cancer (CRC) screening, with a concomitant increased emphasis on detection of even the smallest adenomas, has resulted in a new clinical challenge. An increased number of people are being identified as harboring an adenomatous polyp, the benign precursor to CRC. These patients are recommended to undergo surveillance, or repeated colonoscopy for monitoring for recurrence ...

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    22. Miniaturized precalibration-based Lissajous scanning fiber probe for high speed endoscopic optical coherence tomography

      Miniaturized precalibration-based Lissajous scanning fiber probe for high speed endoscopic optical coherence tomography

      We present a miniaturized precalibration-based forward-viewing Lissajous scanning fiber probe for high speed endoscopic optical coherence tomography (OCT). The probe is based on an asymmetric fiber cantilever driven by the piezoelectric bender to realize two-dimensional (2D) Lissajous scanning. The stability and repeatability of the Lissajous scanning trajectory of the probe is tested by a position sensitive detector (PSD)-based position calibration setup. The two orthogonal resonant frequencies of the cantilever are measured to be 167.2 and 121 Hz. A 25 µm focal spot is formed at the working distance of 5 mm by the graded-index (GRIN) lens, and the ...

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    23. 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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