Celiac disease(CD)is an autoimmune disease of the small bowel induced by ingestion of wheat,rye and barley.Current guidelines indicate histological analysis on at least four duodenal biopsies as the only way to diagno...Celiac disease(CD)is an autoimmune disease of the small bowel induced by ingestion of wheat,rye and barley.Current guidelines indicate histological analysis on at least four duodenal biopsies as the only way to diagnose CD.These indications are based on the conception of the inability of standard endoscopy to make diagnosis of CD and/or to drive biopsy sampling.Over the last years,technology development of endoscopic devices has greatly ameliorated the accuracy of macroscopic evaluation of duodenal villous pattern,increasing the diagnostic power of endoscopy of CD.The aim of this paper is to review the new endoscopic tools and procedures proved to be useful in the diagnosis of CD,such as chromoendoscopy,Fujinon Intelligent Chromo Endoscopy,Narrow Band Imaging,Optical Coherence Tomography,Water-Immersion Technique,confocal laser endomicroscopy,high-resolution magnification endoscopy,capsule endoscopy and I-Scan technology.展开更多
AIM: To evaluate the feasibility of a new computed virtual chromoendoscopy (CVC) device (M i-scan) in the diagnosis of gastric neoplasia. METHODS: Patients with superficial lesions no larger than 1.0 cm found during h...AIM: To evaluate the feasibility of a new computed virtual chromoendoscopy (CVC) device (M i-scan) in the diagnosis of gastric neoplasia. METHODS: Patients with superficial lesions no larger than 1.0 cm found during high definition endoscopy were included. Those with advanced or obviously protruded or depressed lesions, lesions larger than 1.0 cm and/or lesions which were not amenable to observation by zoom function were excluded. The endoscopist was required to give the real-time descriptions of surface pit patterns of the lesions, based on surface pattern classification of enhanced magnification endoscopy. According to previous reports, types Ⅰ-Ⅲ represent nonneoplastic lesions, and types Ⅳ-Ⅴ represent neoplastic lesions. Diagnosis with M i-scan and biopsy was performed before histopathological diagnosis. Magnified images of gastric lesions with and without enhancement were collected for further analysis. The diagnostic yield of real-time M i-scan and effects on magnification image quality by tone enhancement (TE), surface enhancement (SE) and color enhancement (CE) were calculated. The selected images were sent to another endoscopist. The endoscopist rated the image quality of each lesion at 3 levels. Ratings of image quality were based on visualization of pit pattern, vessel and demarcation line. RESULTS: One hundred and eighty-three patients were recruited. Five patients were excluded for advanced gastric lesions, 1 patient was excluded for poor preparation and 2 patients were excluded for superficial lesions larger than 1.0 cm; 132 patients were excluded for no lesions found by high definition endoscopy. In the end, 43 patients with 43 lesions were included. Histopathology revealed 10 inflammation, 14 atrophy, 10 metaplasia, 1 low grade dysplasia (LGD), 5 high grade dysplasia (HGD) and 3 cancers. For 7 lesions classified into type Ⅰ, histopathology revealed 6 atrophy and 1 metaplasia; for 10 lesions classified into type Ⅱ, histopathology revealed 2 inflammation, 7 atrophy and 1 metaplasia; for 1展开更多
Recent advances in endoscopic imaging techniques have revolutionized the diagnostic approach of patients with inflammatory bowel disease(IBD).New,emerging endoscopic imaging techniques visualized a plethora of new muc...Recent advances in endoscopic imaging techniques have revolutionized the diagnostic approach of patients with inflammatory bowel disease(IBD).New,emerging endoscopic imaging techniques visualized a plethora of new mucosal details even at the cellular and subcellular level.This review offers an overview about new endoscopic techniques,including chromoendoscopy,magnification endoscopy,spectroscopy,confocal laser endomicroscopy and endocytoscopy in the face of IBD.展开更多
A thorough endoscopic visualization of the digestive mucosa is essential for reaching an accurate diagnosis and to treat the different lesions. Standard white light endoscopes permit a good mucosa examination but, no... A thorough endoscopic visualization of the digestive mucosa is essential for reaching an accurate diagnosis and to treat the different lesions. Standard white light endoscopes permit a good mucosa examination but, nowadays, the introduction of powerful endoscopic instrumentations increased ability to analyze the fi nest details. By applying dyes and zoom-magnifi cation endoscopy further architectural detail of the mucosa can be elucidated. New computed virtual chromoendoscopy have further enhanced optical capabilities for the evaluation of submucosal vascolar pattern. Recently, confocal endomicroscopy and endocytoscopy were proposed for the study of ultrastructural mucosa details. Because of the technological contents of powerful instrumentation, a good knowledge of implemented technologies is mandatory for the endoscopist, nowadays. Nevertheless, there is a big confusion about this topic. We will try to explain these technologies and to clarify this terminology.展开更多
AIM To perform a systematic review and meta-analysis for the diagnostic accuracy of in vivo lesion characterization in colonic inflammatory bowel disease(IBD), using optical imaging techniques, including virtual chrom...AIM To perform a systematic review and meta-analysis for the diagnostic accuracy of in vivo lesion characterization in colonic inflammatory bowel disease(IBD), using optical imaging techniques, including virtual chromoendoscopy(VCE), dye-based chromoendoscopy(DBC), magnification endoscopy and confocal laser endomicroscopy(CLE). METHODS We searched Medline, Embase and the Cochrane library. We performed a bivariate meta-analysis to calculate the pooled estimate sensitivities, specificities, positive and negative likelihood ratios(+LHR,-LHR), diagnostic odds ratios(DOR), and area under the SROC curve(AUSROC) for each technology group. A subgroup analysis was performed to investigate differences in real-time nonmagnified Kudo pit patterns(with VCE and DBC) and real-time CLE.RESULTS We included 22 studies [1491 patients; 4674 polyps, of which 539(11.5%) were neoplastic]. Real-time CLE had a pooled sensitivity of 91%(95%CI: 66%-98%), specificity of 97%(95%CI: 94%-98%), and an AUSROC of 0.98(95%CI: 0.97-0.99). Magnification endoscopy had a pooled sensitivity of 90%(95%CI: 77%-96%)and specificity of 87%(95%CI: 81%-91%). VCE had a pooled sensitivity of 86%(95%CI: 62%-95%) and specificity of 87%(95%CI: 72%-95%). DBC had a pooled sensitivity of 67%(95%CI: 44%-84%) and specificity of 86%(95%CI: 72%-94%). CONCLUSION Real-time CLE is a highly accurate technology for differentiating neoplastic from non-neoplastic lesions in patients with colonic IBD. However, most CLE studies were performed by single expert users within tertiary centres, potentially confounding these results.展开更多
Due to the unique anisotropic chemical and physical properties,two-dimensional(2D)layered materials such as IV-VI monochalcogenides with puckered honeycomb structure,have received considerable interest recently.Among ...Due to the unique anisotropic chemical and physical properties,two-dimensional(2D)layered materials such as IV-VI monochalcogenides with puckered honeycomb structure,have received considerable interest recently.Among the IV-VI layered MX(M=Ge,Sn;X=Se,S)compounds,germanium sulfide(Ge S)stands out for its strongest anisotropic thermal conductivities and figure-of-merit values.Additionally,the layer-independent direct energy bands(Eg^1.6 e V,E1~2.1 e V)of Ge S flake provide excellent insights into further applications as visible photodetectors.Herein,the polarization-tunable nonlinear absorption(NA)patterns of Ge S flake have been systematically investigated.Specifically both the polarization-dependent Raman spectroscopy and the linear absorption(LA)spectroscopy were employed to characterize the lattice orientation and absorption edges of the251-nm Ge S flake.Considering the low damage threshold of Ge S flake,the Ge S/graphene heterostructure was fabricated to increase the threshold without changing the nonlinear properties of Ge S.Our NA results demonstrated that a 600-nm femtosecond laser with different polarizations would excite the saturated-absorption(SA)effect along armchair and reversesaturated-absorption(RSA)effect along zigzag in the Ge S/graphene heterostructure.Moreover,the function of the polarization-based Ge S/graphene heterostructure all-optical switch was experimentally verified.Notably,thanks to the polarization-dependent NA patterns(SA/RSA)of Ge S,the"ON"and"OFF"states of the all-optical switch can be accomplished by high and low transmittance states of continuous-wave laser(532 nm,80 n W),whose state can be controlled by the polarization of femtosecond switching laser(600 nm,35 fs,500 Hz,12 GW cm-2).The ON/OFF ratio can achieve up to 17%by changing polarization,compared with the ratios of 3.0%by increasing the incident power of switching light in our experiment.The polarization-tunable absorption patterns introduced in this work open up real perspectives for the next-generation optoelectronic devi展开更多
There have been major developments in endoscopic imaging techniques in recent years.Endoscopes with high definition and magnification can provide high quality images that allow for the histological estimation of lesio...There have been major developments in endoscopic imaging techniques in recent years.Endoscopes with high definition and magnification can provide high quality images that allow for the histological estimation of lesions in vivo and in situ when combined with ancillary enhancement techniques such as chromoendoscopy(CE)and virtual CE(narrow band imaging fujinon intelligent chromoendoscopy,or i-Scan).Despite the enormous potential for these advanced techniques,their value and feasibility in the clinic are still doubted,particularly in cases of colonic polyps that are slated for removal,where in vivo characterization may be deemed unnecessary.However,there are several advantages offered by such advanced endoscopic imaging.CE with or without magnification demonstrates highly accurate histology and invasion depth prediction,and virtual CE is a feasible and less cumbersome alternative to CE in terms of histological estimation,though not sufficiently accurate for depth invasion prediction.Furthermore,the supplementary information provided by advanced imaging systems can assist the endoscopist in the selection of a strategic approach,such as in deciding whether a colonic lesion should be resected,left in situ,or requires more intensive surgical treatment.Lastly,advanced high-resolution imaging techniques may be more cost effective,such that histopathology of lowrisk lesions following resection can be eliminated.The results of these evaluations and comparisons with traditional CE are presented and discussed.Taken together,the benefits provided by these advanced capabilities justify their development,and advocates their use for the treatment and management of colonic polyps.展开更多
Advanced endoscopic imaging is revolutionizing our way on how to diagnose and treat colorectal lesions. Within recent years a variety of modern endoscopic imaging techniques was introduced to improve adenoma detection...Advanced endoscopic imaging is revolutionizing our way on how to diagnose and treat colorectal lesions. Within recent years a variety of modern endoscopic imaging techniques was introduced to improve adenoma detection rates. Those include high-definition imaging, dye-less chromoendoscopy techniques and novel, highly flexible endoscopes, some of themequipped with balloons or multiple lenses in order to improve adenoma detection rates. In this review we will focus on the newest developments in the field of colonoscopic imaging to improve adenoma detection rates. Described techniques include high-definition imaging, optical chromoendoscopy techniques, virtual chromoendoscopy techniques, the Third Eye Retroscope and other retroviewing devices, the G-EYE endoscope and the Full Spectrum Endoscopy-system.展开更多
AIM:To compare the performance characteristics of Pentax HiLine(PHL)(with i-scan) and Olympus Lucera(OL) systems in a screening population.METHODS:Screening colonoscopies in asymptomatic guaiac faecal occult blood tes...AIM:To compare the performance characteristics of Pentax HiLine(PHL)(with i-scan) and Olympus Lucera(OL) systems in a screening population.METHODS:Screening colonoscopies in asymptomatic guaiac faecal occult blood test-positive patients with PHL(n = 58) and OL(n = 425) colonoscopes were analysed.All procedures were performed by a single colonoscopist.PHL used white-light endoscopy(WLE) on scope insertion and contrast/surface enhancement(i-scan 1) on withdrawal,and OL utilised WLE both on insertion and withdrawal.Patient age,sex,instrument insertion and withdrawal times,nurse assessed patient comfort scores,midazolam and fentanyl doses,procedure completion and rates of lesion detection were recorded separately for each group.Comparisons between the groups were made using either Fisher's exact test(for dichotomous variables) or Mann-Whitney U test(for ordinal and continuous variables).RESULTS:Colonoscopy completion rates were similar in both groups:413/425(97.2%) for OL and 55/58(94.9%) for PHL(P = 0.24).For complete colonoscopies,the two groups were well matched for age,sex,colonoscope insertion times(mean 11.1 min in OL vs 11.6 min in PHL,P = 0.93) and normal colonoscopy withdrawal times(mean 15.6 min in OL vs 14.7 min in PHL,P = 0.2).Patients in the PHL group experienced a small increase in discomfort(mean patient comfort scores were 0.49 in the OL and 0.95 in the PHL group,P < 0.0001).While Fentanyl doses required were similar between groups(mean 57.5 μg in OL vs 61.4 μg in PHL,P = 0.13),slightly more Midazolam was required in the PHL group(mean 2.1 mg in OL vs 2.4 mg in PHL,P = 0.035).There was no difference in polyp(58% in OL vs 67% in PHL) or adenoma(49% in OL vs 56% in PHL) detection rates between the groups.Neither the total number of polyps and adenomas,nor the characteristics of these(including size,location or presence of advanced features) were different between the two systems.CONCLUSION:This study suggests that there is no advantage of either colonoscope system in lesion detection.展开更多
AIM:To examine performances regarding prediction of polyp histology using high-definition (HD) i-scan in a group of endoscopists with varying levels of experience. METHODS:We used a digital library of HD i-scan still ...AIM:To examine performances regarding prediction of polyp histology using high-definition (HD) i-scan in a group of endoscopists with varying levels of experience. METHODS:We used a digital library of HD i-scan still images, comprising twin pictures (surface enhancement and tone enhancement), collected at our university hospital. We defined endoscopic features of adenomatous and non-adenomatous polyps, according to the following parameters:color, surface pattern and vascular pattern. We familiarized the participating endoscopists on optical diagnosis of colorectal polyps using a 20-min didactic training session. All endoscopists were asked to evaluate an image set of 50 colorectal polyps with regard to polyp histology. We classified the diagnoses into high confidence (i.e., cases in which the endoscopist could assign a diagnosis with certainty) and low confidence diagnoses (i.e., cases in which the endoscopist preferred to send the polyp for formal histology). Mean sensitivity, specificity and accuracy per endoscopist/image were computed and differences between groups tested using independent-samples t tests. High vs low confidence diagnoses were compared using the pairedsamples t test. RESULTS:Eleven endoscopists without previous experience on optical diagnosis evaluated a total of 550 images (396 adenomatous, 154 non-adenomatous). Mean sensitivity, specificity and accuracy for diagnosing adenomas were 79.3%, 85.7% and 81.1%, respectively. No significant differences were found between gastroenterologists and trainees regarding performances of optical diagnosis (mean accuracy 78.0%vs 82.9%,P = 0.098). Diminutive lesions were predicted with a lower mean accuracy as compared to non-diminutive lesions (74.2% vs 93.1%, P = 0.008). A total of 446 (81.1%) diagnoses were made with high confidence. High confidence diagnoses corresponded to a significantly higher mean accuracy than low confidence diagnoses (84.0% vs 64.3%, P = 0.008). A total of 319 (58.0%) images were evaluated as having excellent quality. Considering ex展开更多
AIM:To use a survey to characterize and identify potential barriers to the use of digital chromoendoscopy(DC)by practicing gastroenterologists.METHODS:An anonymous,internet-based survey was sent to gastroenterologists...AIM:To use a survey to characterize and identify potential barriers to the use of digital chromoendoscopy(DC)by practicing gastroenterologists.METHODS:An anonymous,internet-based survey was sent to gastroenterologists in Connecticut who were members of one of three national gastrointestinal organizations.The survey collected demographic information,frequency of DC use,types of procedures that the respondent performs,setting of practice(academic vs community),years out of training,amount of training in DC,desire to have DC training and perceived barriers to DC use.Responses were collected anonymously.The primary endpoint was the proportion of endoscopists utilizing DC.Associations between the various data collected were analyzed usingχ2 test.RESULTS:One hundred and twenty-four gastroenterologists(48%)of 261 who received the online survey responded.Seventy-eight percent of surveyed gastroenterologists have used DC during the performance of upper endoscopy and 81%with lower endoscopy.DC was used in more than half of procedures by only 14%of gastroenterologists during upper endoscopy and 12%during lower endoscopy.Twenty-three percent(upper)and 21%(lower)used DC more than one quarter of the time.DC was used for 10%or less of endoscopies by 60%(upper)and53%(lower)of respondents.Endoscopists reported lack of training as the leading deterrent to DC use with36%reporting it as their primary deterrent.Eighty-nine percent of endoscopists never received formal training in DC.Lack of time(30%of respondents),lack of evidence(24%)and lack of reimbursement(10%)were additional deterrents.There were no differences in DC use relative to academic vs community practice setting or years out of training.CONCLUSION:DC is used infrequently by most endoscopists,primarily due to a lack of training.Training opportunities should be expanded to meet the interest expressed by the majority of endoscopists.展开更多
文摘Celiac disease(CD)is an autoimmune disease of the small bowel induced by ingestion of wheat,rye and barley.Current guidelines indicate histological analysis on at least four duodenal biopsies as the only way to diagnose CD.These indications are based on the conception of the inability of standard endoscopy to make diagnosis of CD and/or to drive biopsy sampling.Over the last years,technology development of endoscopic devices has greatly ameliorated the accuracy of macroscopic evaluation of duodenal villous pattern,increasing the diagnostic power of endoscopy of CD.The aim of this paper is to review the new endoscopic tools and procedures proved to be useful in the diagnosis of CD,such as chromoendoscopy,Fujinon Intelligent Chromo Endoscopy,Narrow Band Imaging,Optical Coherence Tomography,Water-Immersion Technique,confocal laser endomicroscopy,high-resolution magnification endoscopy,capsule endoscopy and I-Scan technology.
基金Supported by The National Clinical Project from the Health Ministry of Chinathe Shandong Province Science and Technology Committee, No. 2010GSF10247National Natural Foundation of Science of China, No. NSFC81101098
文摘AIM: To evaluate the feasibility of a new computed virtual chromoendoscopy (CVC) device (M i-scan) in the diagnosis of gastric neoplasia. METHODS: Patients with superficial lesions no larger than 1.0 cm found during high definition endoscopy were included. Those with advanced or obviously protruded or depressed lesions, lesions larger than 1.0 cm and/or lesions which were not amenable to observation by zoom function were excluded. The endoscopist was required to give the real-time descriptions of surface pit patterns of the lesions, based on surface pattern classification of enhanced magnification endoscopy. According to previous reports, types Ⅰ-Ⅲ represent nonneoplastic lesions, and types Ⅳ-Ⅴ represent neoplastic lesions. Diagnosis with M i-scan and biopsy was performed before histopathological diagnosis. Magnified images of gastric lesions with and without enhancement were collected for further analysis. The diagnostic yield of real-time M i-scan and effects on magnification image quality by tone enhancement (TE), surface enhancement (SE) and color enhancement (CE) were calculated. The selected images were sent to another endoscopist. The endoscopist rated the image quality of each lesion at 3 levels. Ratings of image quality were based on visualization of pit pattern, vessel and demarcation line. RESULTS: One hundred and eighty-three patients were recruited. Five patients were excluded for advanced gastric lesions, 1 patient was excluded for poor preparation and 2 patients were excluded for superficial lesions larger than 1.0 cm; 132 patients were excluded for no lesions found by high definition endoscopy. In the end, 43 patients with 43 lesions were included. Histopathology revealed 10 inflammation, 14 atrophy, 10 metaplasia, 1 low grade dysplasia (LGD), 5 high grade dysplasia (HGD) and 3 cancers. For 7 lesions classified into type Ⅰ, histopathology revealed 6 atrophy and 1 metaplasia; for 10 lesions classified into type Ⅱ, histopathology revealed 2 inflammation, 7 atrophy and 1 metaplasia; for 1
文摘Recent advances in endoscopic imaging techniques have revolutionized the diagnostic approach of patients with inflammatory bowel disease(IBD).New,emerging endoscopic imaging techniques visualized a plethora of new mucosal details even at the cellular and subcellular level.This review offers an overview about new endoscopic techniques,including chromoendoscopy,magnification endoscopy,spectroscopy,confocal laser endomicroscopy and endocytoscopy in the face of IBD.
文摘 A thorough endoscopic visualization of the digestive mucosa is essential for reaching an accurate diagnosis and to treat the different lesions. Standard white light endoscopes permit a good mucosa examination but, nowadays, the introduction of powerful endoscopic instrumentations increased ability to analyze the fi nest details. By applying dyes and zoom-magnifi cation endoscopy further architectural detail of the mucosa can be elucidated. New computed virtual chromoendoscopy have further enhanced optical capabilities for the evaluation of submucosal vascolar pattern. Recently, confocal endomicroscopy and endocytoscopy were proposed for the study of ultrastructural mucosa details. Because of the technological contents of powerful instrumentation, a good knowledge of implemented technologies is mandatory for the endoscopist, nowadays. Nevertheless, there is a big confusion about this topic. We will try to explain these technologies and to clarify this terminology.
文摘AIM To perform a systematic review and meta-analysis for the diagnostic accuracy of in vivo lesion characterization in colonic inflammatory bowel disease(IBD), using optical imaging techniques, including virtual chromoendoscopy(VCE), dye-based chromoendoscopy(DBC), magnification endoscopy and confocal laser endomicroscopy(CLE). METHODS We searched Medline, Embase and the Cochrane library. We performed a bivariate meta-analysis to calculate the pooled estimate sensitivities, specificities, positive and negative likelihood ratios(+LHR,-LHR), diagnostic odds ratios(DOR), and area under the SROC curve(AUSROC) for each technology group. A subgroup analysis was performed to investigate differences in real-time nonmagnified Kudo pit patterns(with VCE and DBC) and real-time CLE.RESULTS We included 22 studies [1491 patients; 4674 polyps, of which 539(11.5%) were neoplastic]. Real-time CLE had a pooled sensitivity of 91%(95%CI: 66%-98%), specificity of 97%(95%CI: 94%-98%), and an AUSROC of 0.98(95%CI: 0.97-0.99). Magnification endoscopy had a pooled sensitivity of 90%(95%CI: 77%-96%)and specificity of 87%(95%CI: 81%-91%). VCE had a pooled sensitivity of 86%(95%CI: 62%-95%) and specificity of 87%(95%CI: 72%-95%). DBC had a pooled sensitivity of 67%(95%CI: 44%-84%) and specificity of 86%(95%CI: 72%-94%). CONCLUSION Real-time CLE is a highly accurate technology for differentiating neoplastic from non-neoplastic lesions in patients with colonic IBD. However, most CLE studies were performed by single expert users within tertiary centres, potentially confounding these results.
基金financial support from the National Natural Science Foundation of China(11802339,11805276,61805282,61801498,11804387,and 11902358)the Scientific Researches Foundation of National University of Defense Technology(ZK16-03-59,ZK18-01-03,ZK18-03-36,and ZK18-03-22)+4 种基金the Natural Science Foundation of Hunan province(2016JJ1021)the Open Director Fund of State Key Laboratory of Pulsed Power Laser Technology(SKL2018ZR05)the Open Research Fund of Hunan Provincial Key Laboratory of High Energy Technology(GNJGJS03)the Opening Foundation of State Key Laboratory of Laser Interaction with Matter(SKLLIM1702)the Youth Talent Lifting Project(17-JCJQ-QT004)。
文摘Due to the unique anisotropic chemical and physical properties,two-dimensional(2D)layered materials such as IV-VI monochalcogenides with puckered honeycomb structure,have received considerable interest recently.Among the IV-VI layered MX(M=Ge,Sn;X=Se,S)compounds,germanium sulfide(Ge S)stands out for its strongest anisotropic thermal conductivities and figure-of-merit values.Additionally,the layer-independent direct energy bands(Eg^1.6 e V,E1~2.1 e V)of Ge S flake provide excellent insights into further applications as visible photodetectors.Herein,the polarization-tunable nonlinear absorption(NA)patterns of Ge S flake have been systematically investigated.Specifically both the polarization-dependent Raman spectroscopy and the linear absorption(LA)spectroscopy were employed to characterize the lattice orientation and absorption edges of the251-nm Ge S flake.Considering the low damage threshold of Ge S flake,the Ge S/graphene heterostructure was fabricated to increase the threshold without changing the nonlinear properties of Ge S.Our NA results demonstrated that a 600-nm femtosecond laser with different polarizations would excite the saturated-absorption(SA)effect along armchair and reversesaturated-absorption(RSA)effect along zigzag in the Ge S/graphene heterostructure.Moreover,the function of the polarization-based Ge S/graphene heterostructure all-optical switch was experimentally verified.Notably,thanks to the polarization-dependent NA patterns(SA/RSA)of Ge S,the"ON"and"OFF"states of the all-optical switch can be accomplished by high and low transmittance states of continuous-wave laser(532 nm,80 n W),whose state can be controlled by the polarization of femtosecond switching laser(600 nm,35 fs,500 Hz,12 GW cm-2).The ON/OFF ratio can achieve up to 17%by changing polarization,compared with the ratios of 3.0%by increasing the incident power of switching light in our experiment.The polarization-tunable absorption patterns introduced in this work open up real perspectives for the next-generation optoelectronic devi
基金Supported by The CIBERehd(Centro de Investigación Biomédica en Red,enfermedades hepaticas y digestivas)to Sanabria E
文摘There have been major developments in endoscopic imaging techniques in recent years.Endoscopes with high definition and magnification can provide high quality images that allow for the histological estimation of lesions in vivo and in situ when combined with ancillary enhancement techniques such as chromoendoscopy(CE)and virtual CE(narrow band imaging fujinon intelligent chromoendoscopy,or i-Scan).Despite the enormous potential for these advanced techniques,their value and feasibility in the clinic are still doubted,particularly in cases of colonic polyps that are slated for removal,where in vivo characterization may be deemed unnecessary.However,there are several advantages offered by such advanced endoscopic imaging.CE with or without magnification demonstrates highly accurate histology and invasion depth prediction,and virtual CE is a feasible and less cumbersome alternative to CE in terms of histological estimation,though not sufficiently accurate for depth invasion prediction.Furthermore,the supplementary information provided by advanced imaging systems can assist the endoscopist in the selection of a strategic approach,such as in deciding whether a colonic lesion should be resected,left in situ,or requires more intensive surgical treatment.Lastly,advanced high-resolution imaging techniques may be more cost effective,such that histopathology of lowrisk lesions following resection can be eliminated.The results of these evaluations and comparisons with traditional CE are presented and discussed.Taken together,the benefits provided by these advanced capabilities justify their development,and advocates their use for the treatment and management of colonic polyps.
文摘Advanced endoscopic imaging is revolutionizing our way on how to diagnose and treat colorectal lesions. Within recent years a variety of modern endoscopic imaging techniques was introduced to improve adenoma detection rates. Those include high-definition imaging, dye-less chromoendoscopy techniques and novel, highly flexible endoscopes, some of themequipped with balloons or multiple lenses in order to improve adenoma detection rates. In this review we will focus on the newest developments in the field of colonoscopic imaging to improve adenoma detection rates. Described techniques include high-definition imaging, optical chromoendoscopy techniques, virtual chromoendoscopy techniques, the Third Eye Retroscope and other retroviewing devices, the G-EYE endoscope and the Full Spectrum Endoscopy-system.
文摘AIM:To compare the performance characteristics of Pentax HiLine(PHL)(with i-scan) and Olympus Lucera(OL) systems in a screening population.METHODS:Screening colonoscopies in asymptomatic guaiac faecal occult blood test-positive patients with PHL(n = 58) and OL(n = 425) colonoscopes were analysed.All procedures were performed by a single colonoscopist.PHL used white-light endoscopy(WLE) on scope insertion and contrast/surface enhancement(i-scan 1) on withdrawal,and OL utilised WLE both on insertion and withdrawal.Patient age,sex,instrument insertion and withdrawal times,nurse assessed patient comfort scores,midazolam and fentanyl doses,procedure completion and rates of lesion detection were recorded separately for each group.Comparisons between the groups were made using either Fisher's exact test(for dichotomous variables) or Mann-Whitney U test(for ordinal and continuous variables).RESULTS:Colonoscopy completion rates were similar in both groups:413/425(97.2%) for OL and 55/58(94.9%) for PHL(P = 0.24).For complete colonoscopies,the two groups were well matched for age,sex,colonoscope insertion times(mean 11.1 min in OL vs 11.6 min in PHL,P = 0.93) and normal colonoscopy withdrawal times(mean 15.6 min in OL vs 14.7 min in PHL,P = 0.2).Patients in the PHL group experienced a small increase in discomfort(mean patient comfort scores were 0.49 in the OL and 0.95 in the PHL group,P < 0.0001).While Fentanyl doses required were similar between groups(mean 57.5 μg in OL vs 61.4 μg in PHL,P = 0.13),slightly more Midazolam was required in the PHL group(mean 2.1 mg in OL vs 2.4 mg in PHL,P = 0.035).There was no difference in polyp(58% in OL vs 67% in PHL) or adenoma(49% in OL vs 56% in PHL) detection rates between the groups.Neither the total number of polyps and adenomas,nor the characteristics of these(including size,location or presence of advanced features) were different between the two systems.CONCLUSION:This study suggests that there is no advantage of either colonoscope system in lesion detection.
文摘AIM:To examine performances regarding prediction of polyp histology using high-definition (HD) i-scan in a group of endoscopists with varying levels of experience. METHODS:We used a digital library of HD i-scan still images, comprising twin pictures (surface enhancement and tone enhancement), collected at our university hospital. We defined endoscopic features of adenomatous and non-adenomatous polyps, according to the following parameters:color, surface pattern and vascular pattern. We familiarized the participating endoscopists on optical diagnosis of colorectal polyps using a 20-min didactic training session. All endoscopists were asked to evaluate an image set of 50 colorectal polyps with regard to polyp histology. We classified the diagnoses into high confidence (i.e., cases in which the endoscopist could assign a diagnosis with certainty) and low confidence diagnoses (i.e., cases in which the endoscopist preferred to send the polyp for formal histology). Mean sensitivity, specificity and accuracy per endoscopist/image were computed and differences between groups tested using independent-samples t tests. High vs low confidence diagnoses were compared using the pairedsamples t test. RESULTS:Eleven endoscopists without previous experience on optical diagnosis evaluated a total of 550 images (396 adenomatous, 154 non-adenomatous). Mean sensitivity, specificity and accuracy for diagnosing adenomas were 79.3%, 85.7% and 81.1%, respectively. No significant differences were found between gastroenterologists and trainees regarding performances of optical diagnosis (mean accuracy 78.0%vs 82.9%,P = 0.098). Diminutive lesions were predicted with a lower mean accuracy as compared to non-diminutive lesions (74.2% vs 93.1%, P = 0.008). A total of 446 (81.1%) diagnoses were made with high confidence. High confidence diagnoses corresponded to a significantly higher mean accuracy than low confidence diagnoses (84.0% vs 64.3%, P = 0.008). A total of 319 (58.0%) images were evaluated as having excellent quality. Considering ex
文摘AIM:To use a survey to characterize and identify potential barriers to the use of digital chromoendoscopy(DC)by practicing gastroenterologists.METHODS:An anonymous,internet-based survey was sent to gastroenterologists in Connecticut who were members of one of three national gastrointestinal organizations.The survey collected demographic information,frequency of DC use,types of procedures that the respondent performs,setting of practice(academic vs community),years out of training,amount of training in DC,desire to have DC training and perceived barriers to DC use.Responses were collected anonymously.The primary endpoint was the proportion of endoscopists utilizing DC.Associations between the various data collected were analyzed usingχ2 test.RESULTS:One hundred and twenty-four gastroenterologists(48%)of 261 who received the online survey responded.Seventy-eight percent of surveyed gastroenterologists have used DC during the performance of upper endoscopy and 81%with lower endoscopy.DC was used in more than half of procedures by only 14%of gastroenterologists during upper endoscopy and 12%during lower endoscopy.Twenty-three percent(upper)and 21%(lower)used DC more than one quarter of the time.DC was used for 10%or less of endoscopies by 60%(upper)and53%(lower)of respondents.Endoscopists reported lack of training as the leading deterrent to DC use with36%reporting it as their primary deterrent.Eighty-nine percent of endoscopists never received formal training in DC.Lack of time(30%of respondents),lack of evidence(24%)and lack of reimbursement(10%)were additional deterrents.There were no differences in DC use relative to academic vs community practice setting or years out of training.CONCLUSION:DC is used infrequently by most endoscopists,primarily due to a lack of training.Training opportunities should be expanded to meet the interest expressed by the majority of endoscopists.
