10 results
Search Results
2. First-in-human pilot study of snapshot multispectral endoscopy for early detection of Barrett's-related neoplasia
- Author
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Sophia Bano, Wladyslaw Januszewicz, Dan Stoyanov, Rebecca C. Fitzgerald, Dale J. Waterhouse, Massimiliano di Pietro, and Sarah E. Bohndiek
- Subjects
Paper ,Esophageal Neoplasms ,Computer science ,multispectral ,Multispectral image ,Biomedical Engineering ,Early detection ,Pilot Projects ,Imaging ,Biomaterials ,Cohort Studies ,Barrett Esophagus ,dysplasia ,Humans ,Computer vision ,endoscopy ,Research data ,esophagus ,Contextual image classification ,business.industry ,computer assisted diagnosis ,First in human ,Atomic and Molecular Physics, and Optics ,digestive system diseases ,Electronic, Optical and Magnetic Materials ,Tissue optics ,Snapshot (computer storage) ,Artificial intelligence ,Esophagoscopy ,business - Abstract
Significance: The early detection of dysplasia in patients with Barrett’s esophagus could improve outcomes by enabling curative intervention; however, dysplasia is often inconspicuous using conventional white-light endoscopy. Aim: We sought to determine whether multispectral imaging (MSI) could be applied in endoscopy to improve detection of dysplasia in the upper gastrointestinal (GI) tract. Approach: We used a commercial fiberscope to relay imaging data from within the upper GI tract to a snapshot MSI camera capable of collecting data from nine spectral bands. The system was deployed in a pilot clinical study of 20 patients (ClinicalTrials.gov NCT03388047) to capture 727 in vivo image cubes matched with gold-standard diagnosis from histopathology. We compared the performance of seven learning-based methods for data classification, including linear discriminant analysis, k-nearest neighbor classification, and a neural network. Results: Validation of our approach using a Macbeth color chart achieved an image-based classification accuracy of 96.5%. Although our patient cohort showed significant intra- and interpatient variance, we were able to resolve disease-specific contributions to the recorded MSI data. In classification, a combined principal component analysis and k-nearest-neighbor approach performed best, achieving accuracies of 95.8%, 90.7%, and 76.1%, respectively, for squamous, non-dysplastic Barrett’s esophagus and neoplasia based on majority decisions per-image. Conclusions: MSI shows promise for disease classification in Barrett’s esophagus and merits further investigation as a tool in high-definition “chip-on-tip” endoscopes.
- Published
- 2021
3. USB capsule endoscope for retrograde imaging of the esophagus
- Author
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Peter Banovcin, Ivan Martincek, Matej Goraus, and Martin Duricek
- Subjects
Paper ,medicine.medical_specialty ,Endoscope ,Biomedical Engineering ,esophagogastroduodenoscopy ,USB ,01 natural sciences ,Capsule Endoscopy ,retrograde imaging ,law.invention ,Imaging ,010309 optics ,Biomaterials ,Esophagus ,Capsule endoscopy ,law ,0103 physical sciences ,medicine ,Humans ,capsule endoscope ,Endoscopes ,Capsule Endoscopes ,medicine.diagnostic_test ,Esophagogastroduodenoscopy ,business.industry ,Endoscopic Procedure ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Endoscopy ,Gastrointestinal Tract ,medicine.anatomical_structure ,Radiology ,business - Abstract
Significance: Endoscopes represent electro-optical devices that are used to visualize internal body cavities. The specialized endoscopic procedure of the upper gastrointestinal tract from the esophagus down to the duodenum is called an esophagogastroduodenoscopy. Aim: We bring our newly developed capsule endoscopy device as a promising alternative diagnostic method for visualization of the upper gastrointestinal tract. Approach: Capsule endoscopy has become an attractive method that uses a tiny wireless camera to take pictures of the digestive tract. Existing esophageal capsule endoscopy does not allow a retrograde view of the esophagus while retrograde scanning can provide information on the esophageal pathology. Results: In comparison to the existing esophageal capsule endoscopy, our system is much simpler and cheaper due to the need for fewer electronic devices. Moreover, its use is not limited by the capacity of the batteries used by existing capsule endoscopes. The new esophageal endoscopic system was created by combining the universal serial bus (USB) endoscope module with the thin power wires that are routed through the USB port to the computer. Conclusions: The endoscope was tested on a volunteer without any side effects such as nausea, belching, and general discomfort. The examination of the patient is performed in a sitting position and the patient discomfort during the examination is minimal so it can be performed without anesthesia.
- Published
- 2020
4. Quantitative phase and polarization imaging through an optical fiber applied to detection of early esophageal tumorigenesis
- Author
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Maria P. Alcolea, Catherine R. M. Fitzpatrick, Sarah E. Bohndiek, Travis W. Sawyer, Rebecca C. Fitzgerald, Philip H. Jones, James Joseph, Massimiliano di Pietro, Timothy D. Wilkinson, Calum Williams, George S. D. Gordon, Gordon, George [0000-0002-7333-5106], Alcolea Delgado, Maria [0000-0002-8396-6454], Williams, Calum [0000-0002-6432-6515], Fitzpatrick, Catherine [0000-0002-8866-9547], Jones, Philip [0000-0002-5904-795X], Di Pietro, Massimiliano [0000-0003-4866-7026], Fitzgerald, Rebecca [0000-0002-3434-3568], Wilkinson, Timothy [0000-0001-8885-1288], Bohndiek, Sarah [0000-0003-0371-8635], and Apollo - University of Cambridge Repository
- Subjects
Paper ,Male ,optical fibers ,Optical fiber ,Materials science ,quantitative phase imaging ,Esophageal Neoplasms ,Biomedical Engineering ,Polarimetry ,Phase (waves) ,Holography ,01 natural sciences ,Imaging ,law.invention ,010309 optics ,Biomaterials ,Mice ,03 medical and health sciences ,Esophagus ,Optical imaging ,Optics ,law ,Image Interpretation, Computer-Assisted ,0103 physical sciences ,cancer ,Animals ,polarimetry ,030304 developmental biology ,0303 health sciences ,Birefringence ,Phantoms, Imaging ,business.industry ,Optical Imaging ,Polarization imaging ,Polarization (waves) ,Atomic and Molecular Physics, and Optics ,3. Good health ,Electronic, Optical and Magnetic Materials ,Mice, Inbred C57BL ,Female ,business ,Algorithms - Abstract
Phase and polarization of coherent light are highly perturbed by interaction with microstructural changes in premalignant tissue, holding promise for label-free detection of early tumors in endoscopically accessible tissues such as the gastrointestinal tract. Flexible optical multicore fiber (MCF) bundles used in conventional diagnostic endoscopy and endomicroscopy scramble phase and polarization, restricting clinicians instead to low-contrast amplitude-only imaging. We apply a transmission matrix characterization approach to produce full-field en-face images of amplitude, quantitative phase, and resolved polarimetric properties through an MCF. We first demonstrate imaging and quantification of biologically relevant amounts of optical scattering and birefringence in tissue-mimicking phantoms. We present an entropy metric that enables imaging of phase heterogeneity, indicative of disordered tissue microstructure associated with early tumors. Finally, we demonstrate that the spatial distribution of phase and polarization information enables label-free visualization of early tumors in esophageal mouse tissues, which are not identifiable using conventional amplitude-only information.
- Published
- 2019
5. Endoscopic Ultrasound in Barrett's Oesophagitis with Dysplasia
- Author
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Wray, Andrew, Rice, Paul, and Love, Mark
- Subjects
Paper ,Adult ,Aged, 80 and over ,Male ,Esophageal Neoplasms ,Endoscopic ultrasound ,Middle Aged ,Sensitivity and Specificity ,digestive system diseases ,Oesophagus ,Barrett Esophagus ,Esophagus ,Predictive Value of Tests ,Humans ,Female ,Barrett's metaplasia ,Aged ,Retrospective Studies ,Ultrasonography - Abstract
Purpose With the advent of conservative therapies including photodynamic therapy and endoscopic mucosal resection for Barrett's and high grade dysplasia, accurate staging has become increasingly important. We report our experience with endoscopic ultrasound (EUS) in these patients. Materials and Methods Retrospective review of 25 consecutive patients referred for EUS for assessment of Barrett's with high grade dysplasia and /or stricture or polyp. The findings were compared with subsequent surgical pathology, or endoscopy and biopsy follow up. Results Nine patients were found to have invasive tumour on EUS and this was confirmed in all 9 either by oesophagectomy, OGD and oncology follow up, or by endoscopic mucosal resection. Eight patients underwent oesophagectomy, 5 for invasive tumour and 3 for dysplasia only, with pathological agreement with EUS findings in 7 out of 8 cases. The one discrepancy was a EUS case of mucosal thickening only with no invasion, but pathology showed a T1 lesion. Thirteen patients with no evidence of invasion were managed conservatively, with 11 patients being followed up for 6-12 months with serial OGD and biopsy, and no cases of more invasive disease occurring. Therefore, in our experience the sensitivity, specificity and positive predictive value of EUS in complex Barrett's is 90%, 100% and 100% respectively. Conclusion EUS is valuable in the assessment of high grade dysplasia in cases where conservative therapy is being considered, defining those with more deeply invasive tumour for whom radical treatment is the only option.
- Published
- 2012
6. Duodenal Chemosensing and Mucosal Defenses
- Author
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Jonathan D. Kaunitz and Yasutada Akiba
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Paper ,Duodenum ,Extramural ,Gastroenterology ,Carbon Dioxide ,Hydrogen-Ion Concentration ,Pharmacology ,Chemoreceptor Cells ,Physiological responses ,Receptors, G-Protein-Coupled ,Gastric Acid ,Bicarbonates ,Esophagus ,Biochemistry ,Receptors, Purinergic P2Y ,Humans ,Duodenal mucosa ,Amino Acids ,Intestinal Mucosa ,Receptors, Calcium-Sensing - Abstract
The duodenal mucosa is exposed to endogenous and exogenous chemicals, including acid, CO2, bile acids and nutrients. Mucosal chemical sensors are necessary to exert physiological responses such as secretion, digestion, absorption, and motility. We propose a mucosal chemosensing system by which luminal chemicals are sensed via mucosal acid sensors and G-protein-coupled receptors. Luminal acid/CO2 sensing consists of ecto- and cytosolic carbonic anhydrases, epithelial ion transporters, and acid sensors expressed on the afferent nerves in the duodenum. Furthermore, a luminal L-glutamate signal is mediated via mucosal L-glutamate receptors, including metabotropic glutamate receptors and taste receptor 1 family heterodimers, with activation of afferent nerves and cyclooxygenase, whereas luminal Ca2+ is differently sensed via the calcium-sensing receptor in the duodenum. Recent studies also show the involvement of enteroendocrine G-protein-coupled receptors in bile acid and fatty acid sensing in the duodenum. These luminal chemosensors help activate mucosal defense mechanisms in or- der to maintain the mucosal integrity and physiological responses. Stimulation of luminal chemosensing in the duodenal mucosa may prevent mucosal injury, affect nutrient metabolism, and modulate sensory nerve activity.
- Published
- 2011
7. Endoscopic Ablation of Barrett's Esophagus Using the Halo® System
- Author
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Virender K. Sharma and David E. Fleischer
- Subjects
Paper ,medicine.medical_specialty ,Radiofrequency ablation ,Decision Making ,digestive system ,Gastroenterology ,law.invention ,Barrett Esophagus ,law ,Internal medicine ,otorhinolaryngologic diseases ,medicine ,Humans ,Esophagus ,Clinical Trials as Topic ,business.industry ,General Medicine ,medicine.disease ,Endoscopic ablation ,digestive system diseases ,medicine.anatomical_structure ,surgical procedures, operative ,Barrett's esophagus ,Catheter Ablation ,Adenocarcinoma ,Radiology ,Halo ,Esophagoscopy ,business ,Endoscopic treatment - Abstract
There is increasing interest in the endoscopic treatment of Barrett’s esophagus. Endoscopic treatment has been utilized for many years, but in the past, no specific method has emerged as an appealing treatment option with appropriate safety, efficacy and ease of treatment for both patients and physicians. Recently there has been a growing literature related to the endoscopic ablation of Barrett’s esophagus using radiofrequency ablation (RFA) (Halo® system). In order to discuss when RFA is indicated for Barrett’s, one needs to know: (1) What is the ‘histology’ of the Barrett’s? Does the patient have intestinal metaplasia, low-grade dysplasia, high-grade dysplasia or intramucosal carcinoma? (2) What are the endoscopic options to be considered as opposed to RFA? What are the advantages and disadvantages of each? (3) What additional variables need to be examined?
- Published
- 2009
8. Non-invasive investigation of gastrointestinal functions with magnetic resonance imaging: towards an 'ideal' investigation of gastrointestinal function
- Author
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Mark A. Fox, Werner Schwizer, A. Steingötter, University of Zurich, and Schwizer, W
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Paper ,Pathology ,medicine.medical_specialty ,Direct assessment ,Gastrointestinal Diseases ,610 Medicine & health ,Biology ,170 Ethics ,Esophagus ,medicine ,Humans ,10237 Institute of Biomedical Engineering ,2715 Gastroenterology ,Defecation ,Pancreas ,medicine.diagnostic_test ,Resting state fMRI ,Gastric emptying ,Non invasive ,Gastroenterology ,Magnetic resonance imaging ,Area of interest ,Magnetic Resonance Imaging ,Structure and function ,10219 Clinic for Gastroenterology and Hepatology ,Gastrointestinal function ,Gastrointestinal Motility ,human activities ,Digestive System ,Biomedical engineering - Abstract
Gastrointestinal (GI) function is complex and physiological measurements are subject to a variety of technical difficulties and practical limitations. The ideal technique would be non-invasive, widely available, convenient, and reliable and would not expose the subject to ionising radiation. It would permit direct assessment of GI function in the postprandial as well as the resting state, and be able to differentiate between food, secretion, and air in the lumen. GI structure and function are interdependent and the ideal technique would permit simultaneous assessment of these factors. Finally, the bowel operates as a functional whole and assessment of the GI tract proximal and distal to the area of interest is desirable. In this article the authors summarise the development and validation of magnetic resonance imaging techniques that overcome many of the deficiencies of existing methods, and have many characteristics of the "ideal" investigation of GI function.
- Published
- 2003
9. [Esophageal stenoses with epidermolysis bullosa; remarks on G. W. Korting's paper]
- Author
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F, GROCHOCKI
- Subjects
Paper ,Esophagus ,Esophageal Stenosis ,Humans ,Constriction, Pathologic ,Epidermolysis Bullosa - Published
- 1957
10. A Review and Critcism of Seitaro Goto's Work on the Development of Asterias Pallida
- Author
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MacBride, E. W.
- Published
- 1899
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