New Techniques in Gastrointestinal Endoscopy

As result of progress, endoscopy has became more complex, using more sophisticated devices and has claimed a special form. In this moment, the gastroenterologist performing endoscopy has to be an expert in macroscopic view of the lesions in the gut, with good skills for using standard endoscopes, with good experience in ultrasound (for performing endoscopic ultrasound), with pathology experience for confocal examination. It is compulsory to get experience and to have patience and attention for the follow-up of thousands of images transmitted during capsule endoscopy or to have knowledge in physics necessary for autofluorescence imaging endoscopy. Therefore, the idea of an endoscopist has changed. Examinations mentioned need a special formation, a superior level of instruction, accessible to those who have already gained enough experience in basic diagnostic endoscopy. This is the reason for what these new issues of endoscopy are presented in this book of New techniques in Gastrointestinal Endoscopy

Photoacoustic imaging of colorectal cancer and ovarian cancer

Photoacoustic (PA) imaging is an emerging hybrid imaging technology that uses a short-pulsed laser to excite tissue. The resulting photoacoustic waves are used to image the optical absorption distribution of the tissue, which is directly related to micro-vessel networks and thus to tumor angiogenesis, a key process in tumor growth and metastasis. In this thesis, the acoustic-resolution photoacoustic microscopy (AR-PAM) was first investigated on its role in human colorectal tissue imaging, and the optical-resolution photoacoustic microscopy (OR-PAM) was investigated on its role in human ovarian tissue imaging.Colorectal cancer is the second leading cause of cancer death in the United States. Significant limitations in screening and surveillance modalities continue to hamper early detection of primary cancers or recurrences after therapy. In the first phase of the study, benchtop co-registered ultrasound (US) and AR-PAM systems were constructed and tested in ex vivo human colorectal tissue. In the second phase of the study, a co-registered endorectal AR-PAM imaging system was constructed, and a pilot patient study was conducted on patients with rectal cancer treated with radiation and chemotherapy. To automate the data analysis, we designed and trained convolutional neural networks (PAM-CNN and US-CNN) using mixed ex vivo and in vivo patient data. 22 patients’ ex vivo specimens and five patients’ in vivo images (a total of 2693 US ROIs and 2208 PA ROIs) were used for CNN training and validation. Data from five additional patients were used for testing. A total of 32 participants (mean age, 60 years, range, 35-89 years) were evaluated. Unique PAM imaging markers of complete tumor response were found, specifically recovery of normal submucosal vascular architecture within the treated tumor bed. The PAM-CNN model captured this recovery process and correctly differentiated these changes from a residual tumor tissue. The imaging system remained highly capable of differentiating tumor from normal tissue, achieving an area under receiver operating characteristic curve (AUC) of 0.98 from the five patients tested. By comparison, US-CNN had an AUC of 0.71. As an alternative to CNN, a generalized linear model (GLM) was investigated for classification and results showed that CNN outperformed GLM in classification of both US and PAM images. Ovarian cancer is the leading cause of death among gynecological cancers but is poorly amenable to preoperative diagnosis. In the second project of this thesis, we have investigated the feasibility of “optical biopsy,” using OR-PAM to quantify the microvasculature of ovarian tissue and fallopian tube tissue. The technique was demonstrated using excised human ovary and fallopian tube specimens imaged immediately after surgery. Initially, a commercial software Amira was used to characterize tissue vasculature patterns, and later, an effective and easy-access algorithm was developed to quantify the mean diameter, total length, total volume, and fulfillment rate of tissue vasculature. Our initial results demonstrate the potential of OR-PAM as an imaging tool for quick assessment of ovarian tissue and fallopian tube tissue

Whole Slide Imaging Versus Microscopy for Primary Diagnosis in Surgical Pathology: A Multicenter Blinded Randomized Noninferiority Study of 1992 Cases (Pivotal Study)

Most prior studies of primary diagnosis in surgical pathology using whole slide imaging (WSI) versus microscopy have focused on specific organ systems or included relatively few cases. The objective of this study was to demonstrate that WSI is noninferior to microscopy for primary diagnosis in surgical pathology. A blinded randomized noninferiority study was conducted across the entire range of surgical pathology cases (biopsies and resections, including hematoxylin and eosin, immunohistochemistry, and special stains) from 4 institutions using the original sign-out diagnosis (baseline diagnosis) as the reference standard. Cases were scanned, converted to WSI and randomized. Sixteen pathologists interpreted cases by microscopy or WSI, followed by a wash-out period of ≥4 weeks, after which cases were read by the same observers using the other modality. Major discordances were identified by an adjudication panel, and the differences between major discordance rates for both microscopy (against the reference standard) and WSI (against the reference standard) were calculated. A total of 1992 cases were included, resulting in 15,925 reads. The major discordance rate with the reference standard diagnosis was 4.9% for WSI and 4.6% for microscopy. The difference between major discordance rates for microscopy and WSI was 0.4% (95% confidence interval, -0.30% to 1.01%). The difference in major discordance rates for WSI and microscopy was highest in endocrine pathology (1.8%), neoplastic kidney pathology (1.5%), urinary bladder pathology (1.3%), and gynecologic pathology (1.2%). Detailed analysis of these cases revealed no instances where interpretation by WSI was consistently inaccurate compared with microscopy for multiple observers. We conclude that WSI is noninferior to microscopy for primary diagnosis in surgical pathology, including biopsies and resections stained with hematoxylin and eosin, immunohistochemistry and special stains. This conclusion is valid across a wide variety of organ systems and specimen types

Comparison of machine learning methods for classifying mediastinal lymph node metastasis of non-small cell lung cancer from 18F-FDG PET/CT images

abstract: Background This study aimed to compare one state-of-the-art deep learning method and four classical machine learning methods for classifying mediastinal lymph node metastasis of non-small cell lung cancer (NSCLC) from [superscript 18]F-FDG PET/CT images. Another objective was to compare the discriminative power of the recently popular PET/CT texture features with the widely used diagnostic features such as tumor size, CT value, SUV, image contrast, and intensity standard deviation. The four classical machine learning methods included random forests, support vector machines, adaptive boosting, and artificial neural network. The deep learning method was the convolutional neural networks (CNN). The five methods were evaluated using 1397 lymph nodes collected from PET/CT images of 168 patients, with corresponding pathology analysis results as gold standard. The comparison was conducted using 10 times 10-fold cross-validation based on the criterion of sensitivity, specificity, accuracy (ACC), and area under the ROC curve (AUC). For each classical method, different input features were compared to select the optimal feature set. Based on the optimal feature set, the classical methods were compared with CNN, as well as with human doctors from our institute. Results For the classical methods, the diagnostic features resulted in 81~85% ACC and 0.87~0.92 AUC, which were significantly higher than the results of texture features. CNN’s sensitivity, specificity, ACC, and AUC were 84, 88, 86, and 0.91, respectively. There was no significant difference between the results of CNN and the best classical method. The sensitivity, specificity, and ACC of human doctors were 73, 90, and 82, respectively. All the five machine learning methods had higher sensitivities but lower specificities than human doctors. Conclusions The present study shows that the performance of CNN is not significantly different from the best classical methods and human doctors for classifying mediastinal lymph node metastasis of NSCLC from PET/CT images. Because CNN does not need tumor segmentation or feature calculation, it is more convenient and more objective than the classical methods. However, CNN does not make use of the import diagnostic features, which have been proved more discriminative than the texture features for classifying small-sized lymph nodes. Therefore, incorporating the diagnostic features into CNN is a promising direction for future research.The electronic version of this article is the complete one and can be found online at: https://ejnmmires.springeropen.com/articles/10.1186/s13550-017-0260-

Screening and Surveillance of the Gastrointestinal Tract

This thesis aims to optimise prevention programmes for gastric- and colorectal cancer. The first part consists of studies on surveillance of premalignant gastric lesions. Prospectively, we evaluated current guidelines on the proper identification of patients with premalignant gastric lesions that deserve further follow up. After one extra gastro endoscopy – were guidelines would advise to stop further surveillance - it appeared that a considerable part would have an indication for further surveillance after all. We investigated several possibilities for the improvement of surveillance programmes. To name; the use of a new endoscopy technique, evaluating risk factors within patients (such as smoking and a family history of gastric cancer), and the new possibility of detecting the most important risk factor for the occurrence of gastric cancer – Helicobacter Pylori bacterium – in the fecal test used in colorectal cancer screening. The second part of this thesis consist of studies on colorectal cancer screening. First, the video capsule was used to determine prevalence rates of several abnormalities (benign or malignant) in a general population. Further, a comprehensive retrospective study in 20 European countries was performed on the incidence of colorectal cancer over time within different age groups. This showed that the incidence is increasing mostly at younger ages. Lastly, literature studies were performed in order to further improve and innovate the current colorectal cancer screening programme. We showed that the use of anticoagulants do not affect the fecal blood test used in screening. Also, the video capsule appeared to be a good alternative beside colonoscopy.<br/

Advanced Endoscopic Navigation:Surgical Big Data,Methodology,and Applications

随着科学技术的飞速发展，健康与环境问题日益成为人类面临的最重大问题之一。信息科学、计算机技术、电子工程与生物医学工程等学科的综合应用交叉前沿课题，研究现代工程技术方法，探索肿瘤癌症等疾病早期诊断、治疗和康复手段。本论文综述了计算机辅助微创外科手术导航、多模态医疗大数据、方法论及其临床应用：从引入微创外科手术导航概念出发，介绍了医疗大数据的术前与术中多模态医学成像方法、阐述了先进微创外科手术导航的核心流程包括计算解剖模型、术中实时导航方案、三维可视化方法及交互式软件技术，归纳了各类微创外科手术方法的临床应用。同时，重点讨论了全球各种手术导航技术在临床应用中的优缺点，分析了目前手术导航领域内的最新技术方法。在此基础上，提出了微创外科手术方法正向数字化、个性化、精准化、诊疗一体化、机器人化以及高度智能化的发展趋势。【Abstract】Interventional endoscopy (e.g., bronchoscopy, colonoscopy, laparoscopy, cystoscopy) is a widely performed procedure that involves either diagnosis of suspicious lesions or guidance for minimally invasive surgery in a variety of organs within the body cavity. Endoscopy may also be used to guide the introduction of certain items (e.g., stents) into the body. Endoscopic navigation systems seek to integrate big data with multimodal information (e.g., computed tomography, magnetic resonance images, endoscopic video sequences, ultrasound images, external trackers) relative to the patient's anatomy, control the movement of medical endoscopes and surgical tools, and guide the surgeon's actions during endoscopic interventions. Nevertheless, it remains challenging to realize the next generation of context-aware navigated endoscopy. This review presents a broad survey of various aspects of endoscopic navigation, particularly with respect to the development of endoscopic navigation techniques. First, we investigate big data with multimodal information involved in endoscopic navigation. Next, we focus on numerous methodologies used for endoscopic navigation. We then review different endoscopic procedures in clinical applications. Finally, we discuss novel techniques and promising directions for the development of endoscopic navigation.X.L. acknowledges funding from the Fundamental Research Funds for the Central Universities. T.M.P. acknowledges funding from the Canadian Foundation for Innovation, the Canadian Institutes for Health Research, the National Sciences and Engineering Research Council of Canada, and a grant from Intuitive Surgical Inc

Study on Colonoscopic Findinds in Positive Faecal Occult Blood Testing

INTRODUCTION: Colorectal cancer is the third most common cancer in the world and a leading cause of cancer death in the Western world. There is an increase in incidence of colorectal carcinoma in India due to, economic shift from low income to middle income economy and increase in ageing population, life style and dietary factors. AIMS OF STUDY: 1. To study colonoscopic findings in positive faecal occult blood test patients. 2. To study other screening modalities in colorectal carcinoma. MATERIALS AND METHODS: Patients admitted in various surgical units in thanjavur medical college hospital between January 2013 to July 2014 constitute the materials of this study. The exclusion criteria includes patients with complaints of bleeding PR, altered bowel habits, tenesmus, mucus discharge from PR, spurious diarrhea, mass desending PR ,FOBT within last one year, sigmoidoscopy within last 3 to 5 years, colonoscopy within last 10 years. The inclusion criteria includes patients with age of 50 and above, patients willing for further followup (invasive procedures like colonoscopy & UGI scopy). A total of 200 patients were studied, patients with positive faecal occult blood test are included in this study, those who are negative for FOBT were adviced for follow up, one year later for another FOBT test. RESULT: Only 52 patients were positive for FOBT out of 200 patients. In FOBT positive patients 12 patients are not willing for colonoscopy, 40 patients went through colonoscopy. Of them, 6 had haemorrhoids, 1 had a polyp and a carcinoma each and one other patient had diverticulum rest of patients have normal colonoscopy. CONCLUSION: 1. Faecal occult blood test screening offers no benefit without appropriate follow up diagnostic tests and treatment. 2. It is simple, safe and cost effective but is limited by lack of acceptability, compliance and adherence as well as poor sensitivity and specificity. 3. In considering all the advantages and drawbacks of FOBT in colorectal cancer screening, we can conclude that this examination is certainly better than no testing at all

Improving the Management of Large Colorectal Polyps

This thesis is focused on identifying current practices in the management of large non pedunculated colorectal polyps (LNPCPs) and the development of a structured management framework to improve outcomes. The methodology used includes a systematic review to ascertain current knowledge and retrospective quantitative analysis to identify current LNPCP management outcomes. The English Bowel Cancer Screening Programme (BCSP) which has a high volume of recorded LNPCP data was used to facilitate the latter process. In addition, qualitative analysis using consensus methodology to create best practice guidelines, key performance indicators (KPIs) to audit LNPCP outcomes and a complex polyp multidisciplinary team process was undertaken. The main outcomes of this thesis were: 1. Confirmation of variation in LNPCP management practices leading to variable outcomes 2. Formulation of evidence based and expert consensus LNPCP management guidelines 3. Identification of KPIs to allow audit of LNPCP management and outcomes 4. Identification of pertinent research questions to improve evidence LNPCP base 5. Development and pilot of regional complex polyp multidisciplinary team meetin