1. Articles in category: Gastroenterology

    1-24 of 488 1 2 3 4 ... 19 20 21 »
    1. Advances in upper gastrointestinal endoscopy

      Advances in upper gastrointestinal endoscopy

      The rapidly moving technological advances in gastrointestinal endoscopy have enhanced an endoscopist’s ability to diagnose and treat lesions within the gastrointestinal tract. The improvement in image quality created by the advent of high-definition and magnification endoscopy, alongside image enhancement, produces images of superb quality and detail that empower the endoscopist to identify important lesions that have previously been undetectable. Additionally, we are now seeing technologies emerge, such as optical coherence tomography and confocal laser endomicroscopy, that allow the endoscopist to visualize individual cells on a microscopic level and provide a real time, in vivo histological assessment. Within this article ...

      Read Full Article
    2. Imaging colon cancer development in mice: IL-6 deficiency prevents adenoma in azoxymethane-treated Smad3 knockouts

      Imaging colon cancer development in mice: IL-6 deficiency prevents adenoma in azoxymethane-treated Smad3 knockouts

      The development of colorectal cancer in the azoxymethane-induced mouse model can be observed by using a miniaturized optical coherence tomography (OCT) imaging system. This system is uniquely capable of tracking disease development over time, allowing for the monitoring of morphological changes in the distal colon due to tumor development and the presence of lymphoid aggregates. By using genetically engineered mouse models deficient in Interleukin 6 (IL-6) and Smad family member 3 (Smad3), the role of inflammation on tumor development and the immune system can be elucidated. Smad3 knockout mice develop inflammatory response, wasting, and colitis associated cancer while deficiency of ...

      Read Full Article
    3. Automated segmentation and characterization of esophageal wall in vivo by tethered capsule optical coherence tomography endomicroscopy

      Automated segmentation and characterization of esophageal wall in vivo by tethered capsule optical coherence tomography endomicroscopy

      Optical coherence tomography (OCT) is an optical diagnostic modality that can acquire cross-sectional images of the microscopic structure of the esophagus, including Barrett’s esophagus (BE) and associated dysplasia. We developed a swallowable tethered capsule OCT endomicroscopy (TCE) device that acquires high-resolution images of entire gastrointestinal (GI) tract luminal organs. This device has a potential to become a screening method that identifies patients with an abnormal esophagus that should be further referred for upper endoscopy. Currently, the characterization of the OCT-TCE esophageal wall data set is performed manually, which is time-consuming and inefficient. Additionally, since the capsule optics optimally focus ...

      Read Full Article
    4. Optimal operational conditions for supercontinuum-based ultrahigh-resolution endoscopic OCT imaging

      Optimal operational conditions for supercontinuum-based ultrahigh-resolution endoscopic OCT imaging

      We investigated the optimal operational conditions for utilizing a broadband supercontinuum (SC) source in a portable 800 nm spectral-domain (SD) endoscopic OCT system to enable high resolution, high-sensitivity, and high-speed imaging in vivo . A SC source with a 3-dB bandwidth of ∼ 246     nm was employed to obtain an axial resolution of ∼ 2.7     μm (in air) and an optimal detection sensitivity of ∼ − 107     dB with an imaging speed up to 35 frames/s (at 70 k A-scans/s). The performance of the SC-based SD-OCT endoscopy system was demonstrated by imaging guinea pig esophagus in vivo , achieving image quality comparable to ...

      Read Full Article
    5. NinePoint, Under New Leadership, Bags $31M More For Imaging Tech

      NinePoint, Under New Leadership, Bags $31M More For Imaging Tech

      NinePoint Medical looks to have added roughly $31 million in financing to back its medical imaging technology. According to a regulatory filing , the Bedford, MA-based company has raised about $30.7 million in new venture funding and could add about $10 million more to the pot. The filing lists three investors: they appear to be founding backers Third Rock Ventures and Prospect Venture Partners, and relative newcomer Corning (NYSE: GLW ), which began investing in NinePoint when the company raised a $34 million Series B round in March 2014. Members of each of the three firms—Mark Levin (Third Rock), Russell ...

      Read Full Article
    6. Rotational distortion correction in endoscopic optical coherence tomography based on speckle decorrelation

      Rotational distortion correction in endoscopic optical coherence tomography based on speckle decorrelation

      We present a new technique for the correction of nonuniform rotation distortion in catheter-based optical coherence tomography (OCT), based on the statistics of speckle between A-lines using intensity-based dynamic light scattering. This technique does not rely on tissue features and can be performed on single frames of data, thereby enabling real-time image correction. We demonstrate its suitability in a gastrointestinal (GI) balloon-catheter OCT system, determining the actual rotational speed with high temporal resolution, and present corrected cross-sectional and en face views showing significant enhancement of image quality.

      Read Full Article
    7. Feasibility of optical coherence tomography for the evaluation of Barrett's mucosa buried underneath esophageal squamous epithelium

      Feasibility of optical coherence tomography for the evaluation of Barrett's mucosa buried underneath esophageal squamous epithelium

      Objectives The evaluation of Barrett's glands buried underneath esophageal squamous epithelium becomes increasingly important to achieve curative treatments. However, clinically available endoscopies have critical limitations in depicting the subsurface structure, resulting in non-curative treatments. Optical coherence tomography (OCT) can acquire a high-resolution cross-sectional image, equivalent to an ‘optical biopsy’. We aimed to assess the feasibility of the in vivo use of probe-type OCT imaging to evaluate Barrett's mucosa buried underneath esophageal squamous epithelium Methods We conducted a single-center prospective study with 14 consecutive patients with Barrett's adenocarcinoma from 2008 to 2014. The enrolled patients were examined by ...

      Read Full Article
    8. Advances in the management of Barrett’s esophagus and early esophageal adenocarcinoma

      Advances in the management of Barrett’s esophagus and early esophageal adenocarcinoma

      The incidence of esophageal adenocarcinoma (EAC) has markedly increased in the United States over the last few decades. Barrett’s esophagus (BE) is the most significant known risk factor for this malignancy. Theoretically, screening and treating early BE should help prevent EAC but the exact incidence of BE and its progression to EAC is not entirely known and cost-effectiveness studies for Barrett’s screening are lacking. Over the last few years, there have been major advances in our understanding of the epidemiology, pathogenesis and endoscopic management of BE. These developments focus on early recognition of advanced histology and endoscopic treatment ...

      Read Full Article
    9. The use of optical imaging techniques in the gastrointestinal tract

      The use of optical imaging techniques in the gastrointestinal tract

      With significant advances in the management of gastrointestinal disease there has been a move from diagnosing advanced pathology, to detecting early lesions that are potentially amenable to curative endoscopic treatment. This has required an improvement in diagnostics, with a focus on identifying and characterising subtle mucosal changes. There is great interest in the use of optical technologies to predict histology and enable the formulation of a real-time in vivo diagnosis, a so-called ‘optical biopsy’. The aim of this review is to explore the evidence for the use of the current commercially available imaging techniques in the gastrointestinal tract.

      Read Full Article
    10. Online Tracking and Retargeting with Applications to Optical Biopsy in Gastrointestinal Endoscopic Examinations

      Online Tracking and Retargeting with Applications to Optical Biopsy in Gastrointestinal Endoscopic Examinations

      With recent advances in biophotonics, techniques such as narrow band imaging, confocal laser endomicroscopy, fluorescence spectroscopy, and optical coherence tomography, can be combined with normal white-light endoscopes to provide in vivo microscopic tissue characterisation, potentially avoiding the need for offline histological analysis. Despite the advantages of these techniques to provide online optical biopsy in situ , it is challenging for gastroenterologists to retarget the optical biopsy sites during endoscopic examinations. This is because optical biopsy does not leave any mark on the tissue. Furthermore, typical endoscopic cameras only have a limited field-of-view and the biopsy sites often enter or exit the ...

      Read Full Article
    11. Monitoring disposition of tethered capsule endoscope in esophagus

      Monitoring disposition of tethered capsule endoscope in esophagus

      A scanning flexible endoscope includes a tether attached to a capsule. The tether controls a disposition of the capsule within a body lumen such as the esophagus. A scanning device in the capsule optically scans the adjacent tissue on the inside surface of the body lumen as the capsule is moved axially through the body lumen. A non-contact sensor responds to indicia on the tether to measure a relative position of the tether and the capsule in the body lumen. The indicia can be analog or digital in form and the sensor can be either magnetic, or optical. A wiper ...

      Read Full Article
    12. Advanced Imaging in Barrett’s Esophagus

      Advanced Imaging in Barrett’s Esophagus

      Enhanced imaging technologies such as narrow band imaging, flexible spectral imaging color enhancement, i-Scan, confocal laser endomicroscopy, and optical coherence tomography are readily available for use by endoscopists in routine clinical practice. In November 2014, the American Gastroenterological Association’s Center for GI Innovation and Technology conducted a 2-day workshop to discuss endoscopic image enhancement technologies, focusing on their role in 2 specific clinical conditions (colon polyps and Barrett’s esophagus) and on issues relating to training and implementation of these technologies (white papers). Although the majority of the studies that use enhanced imaging technologies have been positive, these techniques ...

      Read Full Article
    13. Emerging optical methods for surveillance of Barrett's oesophagus

      Emerging optical methods for surveillance of Barrett's oesophagus

      The rapid rise in incidence of oesophageal adenocarcinoma has motivated the need for improved methods for surveillance of Barrett's oesophagus. Early neoplasia is flat in morphology and patchy in distribution and is difficult to detect with conventional white light endoscopy (WLE). Light offers numerous advantages for rapidly visualising the oesophagus, and advanced optical methods are being developed for wide-field and cross-sectional imaging to guide tissue biopsy and stage early neoplasia, respectively. We review key features of these promising methods and address their potential to improve detection of Barrett's neoplasia. The clinical performance of key advanced imaging technologies is ...

      Read Full Article
    14. In vivo molecular imaging of colorectal cancer using quantum dots targeted to vascular endothelial growth factor receptor 2 and optical coherence tomography/laser-induced fluorescence dual-modality imaging

      In vivo molecular imaging of colorectal cancer using quantum dots targeted to vascular endothelial growth factor receptor 2 and optical coherence tomography/laser-induced fluorescence dual-modality imaging

      Optical coherence tomography/laser induced fluorescence (OCT/LIF) dual-modality imaging allows for minimally invasive, nondestructive endoscopic visualization of colorectal cancer in mice. This technology enables simultaneous longitudinal tracking of morphological (OCT) and biochemical (fluorescence) changes as colorectal cancer develops, compared to current methods of colorectal cancer screening in humans that rely on morphological changes alone. We have shown that QDot655 targeted to vascular endothelial growth factor receptor 2 (QD655-VEGFR2) can be applied to the colon of carcinogen-treated mice and provides significantly increased contrast between the diseased and undiseased tissue with high sensitivity and specificity ex vivo . QD655-VEGFR2 was used in ...

      Read Full Article
    15. Comparative Diagnostic Performance of Volumetric Laser Endomicroscopy and Confocal Laser Endomicroscopy in the Detection of Dysplasia Associated with Barrett’s Esophagus

      Comparative Diagnostic Performance of Volumetric Laser Endomicroscopy and Confocal Laser Endomicroscopy in the Detection of Dysplasia Associated with Barrett’s Esophagus

      Background & Aims Probe-based confocal laser endomicroscopy (pCLE) and volumetric laser endomicroscopy (VLE) are advanced endoscopic imaging modalities that may be useful in the diagnosis of dysplasia associated with Barrett’s esophagus (BE). We performed pCLE examination in ex-vivo endoscopic mucosal resection (EMR) specimens and compared the diagnostic performance of using the current VLE scoring index (OCT-SI) and a novel VLE diagnostic algorithm (VLE-DA) for the detection of dysplasia. Methods 27 patients with BE enrolled in a surveillance program at a tertiary center underwent 50 clinically indicated EMRs that were imaged with VLE and pCLE and classified into neoplastic (N=34 ...

      Read Full Article
    16. Beyond Endoscopy-Ultrasound, Optical Coherence Tomography and Confocal Laser Endomicroscopy (Book Chapter)

      Beyond Endoscopy-Ultrasound, Optical Coherence Tomography and Confocal Laser Endomicroscopy (Book Chapter)

      One of the main challenges in endoscopic diagnosis and treatment of upper urinary tract urothelial carcinoma is the complicated anatomy and the small size of the upper urinary tract, resulting in high demands on the armamentarium and expertise of the urologist. Difficulties to reach the complete collecting system could result in an incomplete visual inspection.

      Read Full Article
    17. Miniature endoscopic optical coherence tomography for calculus detection

      Miniature endoscopic optical coherence tomography for calculus detection

      The effective treatment of periodontitis involves the detection and removal of subgingival dental calculus. However, subgingival calculus is more difficult to detect than supragingival calculus because it is firmly attached to root surfaces within periodontal pockets. To achieve a smooth root surface, clinicians often remove excessive amounts of root structure because of decreased visibility. In addition, enamel pearl, a rare type of ectopic enamel formation on the root surface, can easily be confused with dental calculus in the subgingival environment. In this study, we developed a fiber-probe swept-source optical coherence tomography (SSOCT) technique and combined it with the quantitative measurement ...

      Read Full Article
    18. Recent development of optical coherence tomography for preoperative diagnosis of esophageal malignancies

      Recent development of optical coherence tomography for preoperative diagnosis of esophageal malignancies

      Endoscopic diagnosis with histological evidence is necessary to decide the best strategy for treating esophageal squamous cell carcinoma and Barrett’s-associated neoplasia, and the recent development of endoscopic technologies have made possible real-time information of malignant hallmarks. We focused on the development of optical coherence tomography (OCT), the only technology that can depict real-time cross-sectional images with high resolution. With the improvements in image resolution, acquisition rate and demonstrable area of three-dimensional devices with Doppler capability, OCT imaging was shown to enable visualization of structural/ functional alterations in the mucosal/submucosal tissue of the esophagus, resulting in more accurate preoperative ...

      Read Full Article
    19. Finding a needle in a haystack: use of volumetric laser endomicroscopy in targeting focal dysplasia in long-segment Barrett’s esophagus

      Finding a needle in a haystack: use of volumetric laser endomicroscopy in targeting focal dysplasia in long-segment Barrett’s esophagus

      A 64-year-old man underwent esophagoscopy 15 months earlier, which diagnosed long-segment Barrett’s esophagus. Examination of random biopsy specimens yielded a diagnosis of intestinal metaplasia, with 1 biopsy specimen as indefinite for dysplasia. Two subsequent esophagoscopies were performed 6 months apart, and random biopsy specimens were negative for dysplasia. The patient was referred for volumetric laser endomicroscopy (VLE) (NVisionVLE, NinePoint Medical, Cambridge, Mass). At esophagoscopy, high-definition white-light endoscopy showed a 7-cm segment of flat salmon-colored mucosa (Prague class C6M7) ( A ).

      Read Full Article
    20. Detection of buried Barrett’s glands after radiofrequency ablation with volumetric laser endomicroscopy

      Detection of buried Barrett’s glands after radiofrequency ablation with volumetric laser endomicroscopy

      Background and Aims The prevalence and clinical relevance of buried Barrett’s glands (BB) after radiofrequency ablation (RFA) in Barrett’s esophagus (BE) are debated. Recent optical coherence tomography studies demonstrated a high prevalence of BBs. Direct histological correlation, however, has been lacking. Volumetric laser endomicroscopy (VLE) is a second-generation optical coherence tomography system capable of scanning a large surface of the esophageal wall layers with low-power microscopy resolution. The aim was to evaluate whether post-RFA subsquamous glandular structures (SGSs), detected with VLE, actually correspond to BBs by pursuing direct histological correlation with VLE images. Methods In vivo VLE was ...

      Read Full Article
    21. Barrett's Esophagus: Advanced Imaging Options For Early Cancer Detection

      Barrett's Esophagus: Advanced Imaging Options For Early Cancer Detection

      This Video describes the basic approach to endoscopic inspection of Barrett's esophagus. It Focuses on new imaging technologies that increase our ability to detect precancerous or cancerous changes and thus allow us to better target treatment to these areas. For more information on Barrett's Esophagus, visit: http://www.mayoclinic.org/diseases-co...

      Read Full Article
    22. MGH Receives NIH Grant To Study Natural History of Barrett's Esophagus Using Capsule Endomicroscopy

      MGH Receives NIH Grant To Study Natural History of Barrett's Esophagus Using Capsule Endomicroscopy

      Massachusetts General Hospital Receives a 2015 NIH Grant for $472,417 To Study Natural History of Barrett's Esophagus Using Capsule Endomicroscopy. The program began in 2014 and ends in 2019. Below is a summary of the proposed work. Barrett's esophagus (BE) is a condition where normal esophageal squamous mucosa changes to metaplastic columnar mucosa in response to chronic acid reflux. BE can progress to esophageal adenocarcinoma (EAC), a prevalent (~12,000 cases per year) and deadly cancer (~15% 5-year mortality rate). Current BE management strategies of anti-reflux therapy, endoscopic screening, and regular endoscopic biopsy surveillance and ablation therapy ...

      Read Full Article
    23. Endoscopic Mucosal Resection and Endoscopic Submucosal Dissection for Endoscopic Therapy of Barrett’s Esophagus-related Neoplasia

      Endoscopic Mucosal Resection and Endoscopic Submucosal Dissection for Endoscopic Therapy of Barrett’s Esophagus-related Neoplasia

      Barrett’s esophagus (BE) is characterized by a change in the lining of the esophagus from stratified squamous epithelium to a metaplastic columnar epithelium (IM) that has a low, but real, malignant potential. The progression of BE to carcinoma occurs in a stepwise fashion from IM through dysplasia (low grade to high grade [HGD]). Endoscopic surveillance is recommended for patients with BE to detect and manage

      Read Full Article
    24. Miniaturized magnetic-driven scanning probe for endoscopic optical coherence tomography

      Miniaturized magnetic-driven scanning probe for endoscopic optical coherence tomography

      We designed and implemented a magnetic-driven scanning (MDS) probe for endoscopic optical coherence tomography (OCT). The probe uses an externally-driven tiny magnet in the distal end to achieve unobstructed 360-degree circumferential scanning at the side of the probe. The design simplifies the scanning part inside the probe and thus allows for easy miniaturization and cost reduction. We made a prototype probe with an outer diameter of 1.4 mm and demonstrated its capability by acquiring OCT images of ex vivo trachea and artery samples from a pigeon. We used a spectrometer-based Fourier-domain OCT system and the system sensitivity with our ...

      Read Full Article
    1-24 of 488 1 2 3 4 ... 19 20 21 »
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks
  2. Popular Articles

  3. Organizations in the News

    1. (1 articles) Harvard University
    2. (1 articles) Massachusetts General Hospital
    3. (1 articles) University of Arizona
  4. People in the News

    1. (1 articles) Guillermo J. Tearney
    2. (1 articles) Michalina J. Góra
    3. (1 articles) Jennifer K. Barton
    4. (1 articles) Norman S. Nishioka
    5. (1 articles) Giovanni J. Ughi
    6. (1 articles) Photini F. S. Rice