Optical Imaging Technology In Colonoscopy - Is There A Role For Photometric Stereo

AbstractColonoscopy screening for the detection and removal of colonic adenomas is central to efforts to reduce the morbidity and mortality of colorectal cancer. However, up to a third of adenomas may be missed at colonoscopy, and the majority of post-colonoscopy colorectal cancers are thought to arise from these. Adenomas have three-dimensional surface topographic features that differentiate them from adjacent normal mucosa. However, these topographic features are not enhanced by white light colonoscopy, and the endoscopist must infer these from two-dimensional cues. This may contribute to the number of missed lesions. A variety of optical imaging technologies have been developed commercially to enhance surface topography. However, existing techniques enhance surface topography indirectly, and in two dimensions, and the evidence does not wholly support their use in routine clinical practice. In this narrative review, co-authored by gastroenterologists and engineers, we summarise the evidence for the impact of established optical imaging technologies on adenoma detection rate, and review the development of photometric stereo (PS) for colonoscopy. PS is a machine vision technique able to capture a dense array of surface normals to render three-dimensional reconstructions of surface topography. This imaging technique has several potential clinical applications in colonoscopy, including adenoma detection, polyp classification, and facilitating polypectomy, an inherently three-dimensional task. However, the development of PS for colonoscopy is at an early stage. We consider the progress that has been made with PS to date and identify the obstacles that need to be overcome prior to clinical application

Carbohydrate Intake in the Etiology of Crohn's Disease and Ulcerative Colitis

Background: Diet may have a role in the etiology of inflammatory bowel disease. In previous studies, the associations between increased intakes of carbohydrates, sugar, starch, and inflammatory bowel disease are inconsistent. However, few prospective studies have investigated the associations between these macronutrients and incident Crohn's disease (CD) or ulcerative colitis (UC). Methods: A total of 401,326 men and women were recruited between 1991 and 1998. At recruitment, dietary intakes of carbohydrate, sugar, and starch were measured using validated food frequency questionnaires. The cohort was monitored identifying participants who developed incident CD or UC. Cases were matched with 4 controls, and odds ratios were calculated for quintiles of total carbohydrate, sugar, and starch intakes adjusted for total energy intake, body mass index, and smoking. Results: One hundred ten participants developed CD, and 244 participants developed UC during follow-up. The adjusted odds ratio for the highest versus the lowest quintiles of total carbohydrate intake for CD was 0.87, 95% CI = 0.24 to 3.12 and for UC 1.46, 95% CI = 0.62 to 3.46, with no significant trends across quintiles for either (CD, Ptrend = 0.70; UC, Ptrend = 0.41). Similarly, no associations were observed with intakes of total sugar (CD, Ptrend = 0.50; UC, Ptrend = 0.71) or starch (CD, Ptrend = 0.69; UC, Ptrend = 0.17). Conclusions: The lack of associations with these nutrients is in agreement with many case–control studies that have not identified associations with CD or UC. As there is biological plausibility for how specific carbohydrates could have an etiological role in inflammatory bowel disease, future epidemiological work should assess individual carbohydrates, although there does not seem to be a macronutrient effect

The role of diet in the aetiopathogenesis of inflammatory bowel disease

Crohn’s disease and ulcerative colitis, collectively known as IBD, are chronic inflammatory disorders of the gastrointestinal tract. Although the aetiopathogenesis of IBD is largely unknown, it is widely thought that diet has a crucial role in the development and progression of IBD. Indeed, epidemiological and genetic association studies have identified a number of promising dietary and genetic risk factors for IBD. These preliminary studies have led to major interest in investigating the complex interaction between diet, host genetics, the gut microbiota and immune function in the pathogenesis of IBD. In this Review, we discuss the recent epidemiological, gene–environment interaction, microbiome and animal studies that have explored the relationship between diet and the risk of IBD. In addition, we highlight the limitations of these prior studies, in part by explaining their contradictory findings, and review future directions

Efficacy of Budesonide Orodispersible Tablets as Induction Therapy for Eosinophilic Esophagitis in a Randomized Placebo-Controlled Trial.

BACKGROUND & AIMS: Swallowed topical-acting corticosteroids are recommended as first-line therapy for eosinophilic esophagitis (EoE). Asthma medications not optimized for esophageal delivery are sometimes effective, although given off-label. We performed a randomized, placebo-controlled trial to assess the effectiveness and tolerability of a budesonide orodispersible tablet (BOT), which allows the drug to be delivered to the esophagus in adults with active EoE. METHODS: We performed a double-blind, parallel study of 88 adults with active EoE in Europe. Patients were randomly assigned to groups that received BOT (1 mg twice daily; n = 59) or placebo (n = 29) for 6 weeks. The primary end point was complete remission, based on clinical and histologic factors, including dysphagia and odynophagia severity ≤2 on a scale of 0-10 on each of the 7 days before the end of the double-blind phase and a peak eosinophil count <5 eosinophils/high power field. Patients who did not achieve complete remission at the end of the 6-week double-blind phase were offered 6 weeks of open-label treatment with BOT (1 mg twice daily). RESULTS: At 6 weeks, 58% of patients given BOT were in complete remission compared with no patients given placebo (P < .0001). The secondary end point of histologic remission was achieved by 93% of patients given BOT vs no patients given placebo (P < .0001). After 12 weeks, 85% of patients had achieved remission. Six-week and 12-week BOT administration were safe and well tolerated; 5% of patients who received BOT developed symptomatic, mild candida, which was easily treated with an oral antifungal agent. CONCLUSIONS: In a randomized trial of adults with active EoE, we found that budesonide oral tablets were significantly more effective than placebo in inducing clinical and histologic remission. Eudra-CT number 2014-001485-99; ClinicalTrials.gov ID NCT02434029

Young people and IBD : specific challenges for ethnic minority groups

Objective: For young people with IBD, learning to cope with their condition represents a major challenge over and above typical adolescent development: the symptoms and side effects of treatment can have a profound impact leading to social isolation, secretive behaviour and delayed independence. Currently there is a lack of research into the impact of ethnicity in young people with IBD, despite significant increases in the incidence of IBD in Black and Asian communities in the UK and research from other chronic disorders which suggests that ethnicity and cultural identity can affect access to services, health management and social inclusion. This study sought to remedy this. Method: Semi-structured interviews covering a broad range of topics were carried out with 19 young people (16-24y) with IBD of South Asian or Black ethnic backgrounds. The opportune sample was recruited through three NHS gastroenterology departments and was predominantly Asian. Interviews were analysed thematically. Results: The young people interviewed shared many common experiences with young people with IBD who are not Black or Asian, including significant delays in diagnosis and interruptions to education; however, they faced additional challenges related to their ethnicity. The parents of nearly half the sample were not fluent in English and a lack of appropriate information meant that parents and families were inadequately informed about the nature of the illness and, as a consequence, had a poor understanding of IBD, including perceiving it as a short-term illness. This increased stress for the young people and had a negative impact on social support, health care and education. In addition, spicy food, typical of Asian and Black cuisines, triggered or exacerbated the symptoms of IBD for the majority of participants and presented problems exceeding normal IBD dietary-related issues. These were compounded by cultural norms within Asian and Black communities such as the centrality and social importance of sharing food, and respect for elders, and through a lack of familiarity with IBD. Conclusion: Young people with IBD from minority ethnic backgrounds have specific needs, some of which could be readily addressed by healthcare professionals and support organisations. Ensuring that parents have access to appropriate information and raising awareness of the condition within Black and Asian communities would help these young people to receive greater support and understanding.Peer reviewedFinal Accepted Versio

The Role of Vitamin D in Inflammatory Bowel Disease

Vitamin D is known to be vital in maintaining bone health, mineralisation and for fracture prevention. It has also been implicated in a number of autoimmune diseases and has therefore been studied for its potential role in Inflammatory Bowel Disease (IBD). This review looks at the current literature on the role of vitamin D and its potential role as an immunomodulator, disease modifier and bone health in IBD patients. There is substantial supporting evidence of an important role from epidemiological, genetic and immunological studies, but there is also conflicting evidence and nothing proving to be definitive from clinical studies. There are also a number of confounders with IBD patients, as their lifestyles and medications may affect vitamin D levels. Murine studies have added vast amounts to our knowledge of vitamin D and its antimicrobial role, as well as its effect on immune cell proliferation other inflammatory molecules, such as Tumour Necrosis Factor-α (TNFα). It is clear that larger trials investigating the effects of oral supplementation of vitamin D in IBD patients are necessary

A novel photometric stereo imaging sensor for endoscopy imaging: Proof of concept studies on a porcine model

The American Society of Gastroenterology Endoscopy led Preservation and Incorporation of Valuable Endoscopy Innovations initiative has identified real time poly diagnosis as one of the next major technology driven changes in endoscopy (1). A number of imaging techniques are presently being investigated in this area. The complex and demanding nature of the imaging environment, including issues relating to operation in a confined space, the presence of surface fluids and the highly reflective nature of the mucosa areas, renders 3D surface capture and analysis for the purpose of diagnosis an extremely challenging task. A novel Photometric Stereo (PS) imaging sensor has never been previously assessed for mucosal imaging. PS imaging requires the capture of the mucosal regions while illuminated using light from differing known directions and offers the potential for the recovery of high resolution 3D shape and topographic texture data. The captured PS images are then used to recover and analyse the 3D surface geometry