Autofluorescence imaging and magnification endoscopy

It is well known that angiogenesis is critical in the transition from premalignant to malignant lesions.Consequently,early detection and diagnosis based on morphological changes to the microvessels are crucial.In the last few years,new imaging techniques which utilize the properties of light-tissue interaction have been developed to increase early diagnosis of gastrointestinal(GI) tract neoplasia.We analyzed several "red-flag" endoscopic techniques used to enhance visualization of the vascular pattern of preneoplastic and neoplastic lesions(e.g.trimodal imaging including autofluorescence imaging,magnifying endoscopy and narrow band imaging).These new endoscopic techniques provide better visualization of mucosal microsurface structure and microvascular architecture and may enhance the diagnosis and characterization of mucosal lesions in the GI tract.In the near future,it is expected that trimodal imaging endoscopy will be practiced as a standard endoscopy technique as it is quick,safe and accurate for making a precise diagnosis of gastrointestinal pathology,with an emphasis on the diagnosis of early GI tract cancers.Further large-scale randomized controlled trials comparing these modalities in different patient subpopulations are warranted before their endorsement in the routine practice of GI endoscopy.

Autofluorescence imaging endoscopy for identifi cation and assessment of inflammatory ulcerative colitis

AIM:To validate the clinical relevance of autofluores-cence imaging(AFI)endoscopy for the assessment of inflammatory ulcerative colitis(UC).METHODS:A total of 572 endoscopic images were se-lected from 42 UC patients:286 taken with white light imaging(WLI)and 286 with AFI from the same sites.WLI images were assessed for overall mucosal inflammation according to Mayo endoscopic subscore(MES),and for seven characteristic endoscopic features.Likewise,AFI photographs were scored according to relative abundance of red,green and blue color com-ponents within each image based on an RGB additive color model.WLI and AFI endoscopic scores from the same sites were compared.Histological evaluation of biopsies was according to the Riley Index.RESULTS:Relative to red(r=0.52,P<0.01)or blue(r=0.56,P<0.01)color component,the green color component of AFI(r=-0.62,P<0.01)corresponded more closely with mucosal inflammation sites.There were signif icant differences in green color components between MES-0(0.396±0.043)and MES-1(0.340± 0.035)(P<0.01),and between MES-1 and ≥ MES-2(0.318±0.037)(P<0.01).The WLI scores for "vascu-lar patterns"(r=-0.65,P<0.01),"edema"(r=-0.62,P<0.01),histology scores for "polymorphonuclear cells in the lamina propria"(r=-0.51,P<0.01)and "crypt architectural irregularities"(r=-0.51,P<0.01)showed correlation with the green color component of AFI.There were significant differences in green color components between limited(0.399± 0.042)and extensive(0.375±0.044)(P=0.014)polymorpho-nuclear cell inf iltration within MES-0.As the severity of the mucosal inflammation increased,the green color component of AFI decreased.The AFI green color com-ponent was well correlated with the characteristic en-doscopic and histological inflammatory features of UC.CONCLUSION:AFI has application in detecting inflammatory lesions,including microscopic activity in the co-lonic mucosa of UC patients,based on the green color component of images.

Autofluorescence imaging endoscopy can distinguish non-erosive reflux disease from functional heartburn: A pilot study

AIM: To investigate whether autofluorescence imaging(Af I) endoscopy can distinguish non-erosive reflux disease(NERD) from functional heartburn(fh).METHODS: In this prospective observational trial, 127 patients presenting with typical reflux symptoms for > 6 mo were screened. All the participants underwent endoscopy, during which white light imaging(WLI) was followed by Af I. finally 84 patients with normal esophageal appearance on WLI were enrolled. It was defined as being suggestive of NERD if one or more longitudinal purple lines longer than one centimeter were visualized in the distal part of the esophagus during Af I endoscopy. Ambulatory 24-h multichannel intraluminal impedance and ph monitoring was also performed. After standard proton-pump inhibitor(PPI) tests, subjects were divided into an NERD group and an fh group and the diagnostic performance of Af I endoscopy to differentiate NERD from fh was evaluated.RESULTS: Of 84 endoscopy-negative patients, 36(42.9%) had a normal ph/impedance test. Of these, 26 patients with favorable responses to PPI tests were classified as having NERD. finally 10 patients were diagnosed with fh and the others with NERD. Altogether, 68(81.0%) of the 84 patients were positive on Af I endoscopy. In the NERD group, there were 67(90.5%) patients with abnormal esophageal findings on Af I endoscopy while only 1(10%) patient was positive on Af I endoscopy in the fh group. The sensitivity and specificity of AFI in differentiating NERD from FH were 90.5%(95%CI: 81.5%-96.1%) and 90.0%(95%CI: 55.5%-99.7%), respectively. Meanwhile, the accuracy, positive predictive value and negative predictive value of Af I in differentiating between NERD and fh were 90.5%(95%CI: 84.2%-96.8%), 98.5%(95%CI: 92.1%-99.9%) and 56.3%(95%CI: 30.0%-80.2%), respectively.CONCLUSION: Autofluorescence imaging may serve as a complementary method in evaluating patients with NERD and fh.

AUTOFLUORESCENCE EXCITED BY ENDOSCOPIC XENON ION LASER IN THE DIAGNOSIS OF GASTRIC CANCER

Endoscopic xenon ion laser induced autofluorescence spectra in various gastric diseases were tested in 104 patients diagnosed by endoscopy and biopsy, including 28 gastric cancer, 9 gastric ulcer, 46 chronic atrophic gastritis, and 21 superficial gastritis. The autofluorescence spectrum excited with the 365 nm line of pulsed xenon ion laser was measured. The xenon ion laser beam having an output energy of 0.5 mJ with a duration of 0.6μs and a repetition rate of 10 Hz was used as the excitation source. A coaxial optical cable for laser light and autofluorescent light transmission was inserted via the biopsy channel of an endoscope into the cavity of stomach. The tip of opitcal cable was aimed at the gastric tissue and autofluorescence spectrum was plotted on X-Y recorder. As the monochromator scanned in the range 500-750 nm, a single-pulse fluorescence spectrum could be obtained by using an optical multichannel analyser, and then this fluorescence spectrum was stored in the computer. The whole procedure could be completed within 15 seconds. The results of the present study show that autofluorescence spectra of gastric cancer have characteristic peaks near 630 nm and 690 nm, while no such peaks appear in the spectra of the corresponding normal regions. A consistency of 75% was observed in gastric cancer as compared with the pathologic diagnosis. It is claimed that this is a harmless, safe, simple, and fast procedure in the diagnosis of gastric cancer.

Image-enhanced endoscopy for diagnosis of colorectal tumors in view of endoscopic treatment

Recently,image-enhanced endoscopy(IEE) has been used to diagnose gastrointestinal tumors.This method is a change from conventional white-light(WL) endoscopy without dyeing solution,requiring only the push of a button.In IEE,there are many advantages in diagnosis of neoplastic tumors,evaluation of invasion depth for cancerous lesions,and detection of neoplastic lesions.In narrow band imaging(NBI) systems(Olympus Medical Co.,Tokyo,Japan),optical filters that allow narrow-band light to pass at wavelengths of 415 and 540 nm are used.Mucosal surface blood vessels are seen most clearly at 415 nm,which is the wavelength that corresponds to the hemoglobin absorption band,while vessels in the deep layer of the mucosa can be detected at 540 nm.Thus,NBI also can detect pit-like structures named surface pattern.The flexible spectral imaging color enhancement(FICE) system(Fujifilm Medical Co.,Tokyo,Japan) is also an IEE but different to NBI.FICE depends on the use of spectral-estimation technology to reconstruct images at different wavelengths based on WL images.FICE can enhance vascular and surface patterns.The autofluorescence imaging(AFI) video endoscope system(Olympus Medical Co.,Tokyo,Japan) is a new illumination method that uses the difference in intensity of autofluorescence between the normal area and neoplastic lesions.AFI light comprises a blue light for emitting and a green light for hemoglobin absorption.The aim of this review is to highlight the efficacy of IEE for diagnosis of colorectal tumors for endoscopic treatment.

Characteristics of normal human retinal pigment epithelium cells with extremes of autofluorescence or intracellular granule count

Background:Cells of the retinal pigment epithelium(RPE)accumulate different kinds of granules(lipofuscin,melanolipofuscin,melanosomes)within their cell bodies,with lipofuscin and melanolipofuscin being autofluorescent after blue light excitation.High amounts of lipofuscin granules within the RPE have been associated with the development of RPE cell death and age-related macular degeneration(AMD);however,this has not been confirmed in histology so far.Here,based on our previous dataset of RPE granule characteristics,we report the characteristics of RPE cells from human donor eyes that show either high or low numbers of intracellular granules or high or low autofluorescence(AF)intensities.Methods:RPE flatmounts of fifteen human donors were examined using high-resolution structured illumination microscopy(HR-SIM)and laser scanning microscopy(LSM).Autofluorescent granules were analyzed regarding AF phenotype and absolute number of granules.In addition,total AF intensity per cell and granule density(number of granules per cell area)were determined.For the final analysis,RPE cells with total granule number below 5th or above the 95th percentile,or a total AF intensity±1.5 standard deviations above or below the mean were included,and compared to the average RPE cell at the same location.Data are presented as mean±standard deviation.Results:Within 420 RPE cells examined,42 cells were further analyzed due to extremes regarding total granule numbers.In addition,20 RPE cells had AF 1.5 standard deviations below,28 RPE cells above the mean local AF intensity.Melanolipofuscin granules predominate in RPE cells with low granule content and low AF intensity.RPE cells with high granule content have nearly twice(1.8 times)as many granules as an average RPE cell.Conclusions:In normal eyes,outliers regarding autofluorescent granule load and AF intensity signals are rare among RPE cells,suggesting that granule deposition and subsequent AF follows intrinsic control mechanisms at a cellular level.The AF of a cell is related to the composition of intracellular granule types.Ongoing studies using AMD donor eyes will examine possible disease related changes in granule distribution and further put lipofuscin´s role in aging and AMD further into perspective.

Hyperspectral autofluorescence characterization of drusen and sub-RPE deposits in age-related macular degeneration

Background:Soft drusen and basal linear deposit(BLinD)are two forms of the same extracellular lipid rich material that together make up an Oil Spill on Bruch’s membrane(BrM).Drusen are focal and can be recognized clinically.In contrast BLinD is thin and diffusely distributed,and invisible clinically,even on highest resolution OCT,but has been detected on en face hyperspectral autofluorescence(AF)imaging ex vivo.We sought to optimize histologic hyperspectral AF imaging and image analysis for recognition of drusen and sub-RPE deposits(including BLinD and basal laminar deposit),for potential clinical application.Methods:Twenty locations specifically with drusen and 12 additional locations specifically from fovea,perifovea and mid-periphery from RPE/BrM flatmounts from 4 AMD donors underwent hyperspectral AF imaging with 4 excitation wavelengths(λex 436,450,480 and 505 nm),and the resulting image cubes were simultaneously decomposed with our published non-negative matrix factorization(NMF).Rank 4 recovery of 4 emission spectra was chosen for each excitation wavelength.Results:A composite emission spectrum,sensitive and specific for drusen and presumed sub-RPE deposits(the SDr spectrum)was recovered with peak at 510-520 nm in all tissues with drusen,with greatest amplitudes at excitationsλ_(ex)436,450 and 480 nm.The RPE spectra of combined sources Lipofuscin(LF)/Melanolipofuscin(MLF)were of comparable amplitude and consistently recapitulated the spectra S1,S2 and S3 previously reported from all tissues:tissues with drusen,foveal and extra-foveal locations.Conclusions:A clinical hyperspectral AF camera,with properly chosen excitation wavelengths in the blue range and a hyperspectral AF detector,should be capable of detecting and quantifying drusen and sub-RPE deposits,the earliest known lesions of AMD,before any other currently available imaging modality.

Advanced endoscopic imaging in Barrett's oesophagus:A review on current practice

Over the last few years,improvements in endoscopic imaging technology have enabled identification of dysplasia and early cancer in Barrett's oesophagus.New techniques should exhibit high sensitivities and specificities and have good interobserver agreement.They should also be affordable and easily applicable to the community gastroenterologist.Ideally,these modalities must exhibit the capability of imaging wide areas in real time whilst enabling the endoscopist to specifically target abnormal areas.This review will specifically focus on some of the novel endoscopic imaging modalities currently available in routine practice which includes chromoendoscopy,autofluorescence imaging and narrow band imaging.

New aspects of modern endoscopy

The prognosis for patients with malignancies of the ga-strointestinal-tract is strictly dependent on early detec-tion of premalignant and malignant lesions. However, small, flat or depressed neoplastic lesions remain dif-ficult to detect with these technologies thereby limiting their value for polyp and cancer screening. At the same time computer and chip technologies have undergone major technological changes which have greatly im-proved endoscopic diagnostic investigation. New imag-ing modalities and techniques are very notable aspects of modern endoscopy. Chromoendoscopy or filter-aided colonoscopy(virtual chromoendoscopy) with high defi-nition endoscopes is able to enhance the detection and characterization of lesions. Finally, confocal laser en-domicroscopy provides histological confirmation of the presence of neoplastic changes. The developing tech-niques around colonoscopy such as the retro-viewing colonoscope, the balloon-colonoscope or the 330-de-grees-viewing colonoscope try to enhance the efficacy by reducing the adenoma miss rate in right-sided, non-polypoid lesions. Colon capsule endoscopy is limited to identifying cancer and not necessarily small adenomas. Preliminary attempts have been made to introduce this technique in clinical routine.

Recent advances in targeted endoscopic imaging:Early detection of gastrointestinal neoplasms

Molecular imaging has emerged as a new discipline in gastrointestinal endoscopy.This technology encompasses modalities that can visualize disease-specific morphological or functional tissue changes based on the molecular signature of individual cells.Molecular imaging has several advantages including minimal damage to tissues,repetitive visualization,and utility for conducting quantitative analyses.Advancements in basic science coupled with endoscopy have made early detection of gastrointestinal cancer possible.Molecular imaging during gastrointestinal endoscopy requires thedevelopment of safe biomarkers and exogenous probes to detect molecular changes in cells with high specificity anda high signal-to-background ratio.Additionally,a high-resolution endoscope with an accurate wide-field viewing capability must be developed.Targeted endoscopic imaging is expected to improve early diagnosis and individual therapy of gastrointestinal cancer.

MICROENDOSCOPIC SPECTRAL IMAGING AS A TOOL FOR SMALL DUCTUAL DIAGNOSTICS:PRELIMINARY EXPERIENCE

A technical feasibility of autofluorescence ductoscopy in breast milk ducts as blood vessels phantoms has been assessed as successful.Malignant tumor can be clearly identified through the milk ducts.We also present the operation principle as well as the preliminary experimental results of a new type of microsize multicorefiber that enables imaging through blood vessel phantoms.Imaging of a manipulated microwire through a drilled phantom is presented.

NBI及AFE在喉癌早期诊断中的应用

研究表明,喉癌的早期诊断、及时治疗不仅可以提高治愈率,而且也减少了患者的手术创伤和经济负担。积极开展喉癌的早期诊断研究具有重要的临床和社会意义。发现早期喉癌常规方法主要有电子喉镜、纤维喉镜、颈部CT及MRI检查,但并不能明显有效提高早期诊断率。而窄带成像(narrow band imaging,NBI)及自体荧光内镜(autofluorescence endoscopy AFE)是近几年用于喉癌早期诊断的两种新颖的内镜技术。NBI是一种通过变窄光波的波长,使粘膜上皮内乳头样毛细血管袢及粘膜下静脉的结构形成鲜明的对比,从而提高组织表面细微结构的对比度,便于发现病灶。而AFE技术是一种利用自发荧光聚集于病变组织的某个区域产生的差异强度,来区别正常组织与肿瘤性病变,从而用于肿瘤的早期诊断及识别癌前病变。因此,对NBI及AFE的进一步研究及认识对喉癌早期诊断提供非常重要的临床应用价值。

自体荧光内镜对消化道肿瘤的诊断价值

背景：自体荧光内镜应用于临床已十余年,但其对良恶性病变的鉴别仍存在争议.目的：评估自体荧光内镜对消化道肿瘤的诊断价值.方法：对2009年6～11月于上海仁济医院接受手术治疗的110例确诊或疑诊消化道恶性肿瘤患者的手术切除标本（包括病灶组织和周围正常组织）行自体荧光内镜检查,以病理检查结果为标准分析其诊断准确性.结果：自体荧光内镜对早期癌的检出率为86.7%,对进展期癌的检出率为95.5%;其诊断消化道恶性肿瘤的总体敏感性、特异性、阳性预测值、阴性预测值和诊断准确率分别为94.2%、94.0%、93.3%、94.8%和94.1%.结论：自体荧光内镜对消化道恶性肿瘤的诊断具有高敏感性,对检出形态特征不明显的病变较普通内镜有更大优势,易于发现肉眼难以识别的可疑病灶并确定其发生部位和范围,可精确指导活检,对提高早期癌的检出率具有重要意义.

消化内镜自发荧光技术

以自发荧光技术为基础的自发荧光内镜系统,可提供消化道黏膜直观的自发荧光图像,从而发现普通内镜下无法显示的病灶,更精确地引导活检,提高异型增生和癌组织的检出率。本文总结了组织自发荧光产生的机制以及自发荧光技术的发展情况和研究现状。

活体心肌细胞NAD(P)H荧光的光谱分辨的荧光寿命光谱研究

目的 研究实验动物心肌线粒体氧化还原状态,监测缺血时线粒体功能改变的早期信号.方法 线粒体呼吸链主要电子供应者烟酰胺腺嘌呤(磷酸)二核苷酸,或NAD(P)H荧光为无创荧光标记,用光谱分辨的时间相关单光子计数(TCSPC)检测紫外光(UV)激发的心肌自发荧光(AF)光谱和荧光寿命.结果 需用至少3个荧光寿命池0.4～0.7 ns,1.2～1.9 ns和8.0～13.0 ns描述心肌AF.相关衰减光谱(DAS)显示4个NAD(P)H荧光固有光谱,分别为峰值470 nm的短荧光寿命池,及450 nm,470 nm和490 nm的中间和长荧光寿命池.酮体增加线粒体NADH产量,提高AF强度,但不改变荧光寿命.线粒体呼吸阻断剂Rotenone,显著增加AF强度和缩短平均荧光寿命.氧化磷酸化解偶联剂Dinitrophenol (DNP),显著降低AF强度,在520 nm处增宽荧光光谱并显著延长平均荧光寿命.这些结果和NADH荧光动力学离体实验(in vitro)及模拟缺血状态实验有可比性.结论 研究可解释NADH构象改变,以及从NADH到异戎酸脱氢酶(LipDH)结合的黄素蛋白间能量转移的荧光动力学变化.光谱分辨的荧光寿命显微技术提供了在细胞水平上研究心肌能量代谢或线粒体功能障碍的新工具.

Barrett's食管的诊断进展

Barrett's食管(Barrett's esophagus,BE)是指食管内膜发生化生,鳞状上皮被柱状上皮取代,他是食管腺癌最重要的危险因素.随着食管腺癌在西方国家的发病率迅速升高,BE日益受关注.过去几年里,BE领域取得显著的进步,本文主要针对其诊断标准、内镜诊断及新的内镜成像技术等方面作一综述.

食道的有鳞的房间癌 - 先锋损害和早诊断

Squamous cell carcinoma of the esophagus (SCCE) carries a poor prognosis due to late diagnosis.Early detection is highly desirable,since surgical and endoscopic resection offers the only possible cure for esophageal cancer.Population screening should be undertaken in high risk areas,and in low or moderate risk areas for people with risk factors (alcoholics,smokers,mate drinkers,history of head and neck cancer,achalasia and lye stricture of the esophagus).Esophageal balloon cytology is an easy and inexpensive sampling technique,but the current methods are insufficient for primary screening due to sampling errors.Conventional endoscopy with biopsy remains the standard procedure for the identification of pre-malignant and early malignant changes in esophageal mucosa and endoscopic detection.It may be enhanced by several techniques such as dye and optic chromoendoscopy,magnifying endoscopy,and optical-based spectroscopic and imaging modalities.Since more than 80% of SCCE deaths occur in developing countries,where expensive techniques such as narrow band imaging (NBI) and autofluorescence imaging are unavailable,the most cost-effective tool for targeting biopsies may be Lugol dye chromoendoscopy,since it is easy,accurate,inexpensive and available worldwide.In ideal conditions,or in developed countries,is it reasonable to think that optimal detection will require a combination of techniques,such as the combination of Lugol’s chromoendoscopy and NBI to identify esophageal areas that require further characterization by a high resolution technique.The efficacy and cost-effectiveness will determine whether these modalities will become part of standard endoscopy practice.

Light and sound- emerging imaging techniques for inflammatory bowel disease

Patients with inflammatory bowel disease are known to have a high demand of recurrent evaluation for therapy and disease activity. Further, the risk of developing cancer during the disease progression is increasing from year to year. New, mostly non-radiant, quick to perform and quantitative methods are challenging, conventional endoscopy with biopsy as gold standard. Especially, new physical imaging approaches utilizing light and sound waves have facilitated the development of advanced functional and molecular modalities. Besides these advantages they hold the promise to predict personalized therapeutic responses and to spare frequent invasive procedures. Within this article we highlight their potential for initial diagnosis, assessment of disease activity and surveillance of cancer development in established techniques and recent advances such as wide-view full-spectrum endoscopy, chromoendoscopy, autofluorescence endoscopy, endocytoscopy, confocal laser endoscopy, multiphoton endoscopy, molecular imaging endoscopy, B-mode and Doppler ultrasound, contrast-enhanced ultrasound, ultrasound molecular imaging, and elastography.

Era of Barrett’s surveillance: Does equipment matter?

Barrett’s esophagus is a consequence of long standing gastro-esophageal reflux disease and predisposes to the development of esophageal adenocarcinoma. Regular surveillance endoscopies can detect curable early neoplasia in asymptomatic patients, which in turn could improve the prognosis compared to symptomatic cancer. Early neoplastic lesions, which are amenable for local therapy, could be treated endoscopically, avoiding a major surgery. However, in the absence of obvious mucosal lesions, random four quadrant biopsies are done, which is associated with significant sampling error. Newer imaging modalities, such as autofluorescence endoscopy, are helpful in detecting subtle lesions that could be examined in detail with narrow band imaging to characterize and target biopsies. This has the potential benefit of reducing the number of random biopsies with a better yield of dysplasia. Confocal endomicroscopy provides "optical biopsies" and is a valuable tool in targeting biopsies to improve dysplasia detection; however, this is technically challenging. Fuji intelligent chromoendoscopy and I-Scan are recent additions to the imaging armamentarium that have produced notable early results. While all these additional new imaging techniques are promising, a thorough examination by high resolution white light endoscopy after clearing the mucosa with mucolytics should be the minimum standard to improve dysplasia detection during Barrett’s surveillance.

自体荧光内镜对消化道肿瘤诊断临床应用分析

目的探讨自体荧光内镜在消化道癌前病变和恶性肿瘤中的应用价值。方法选取2017年3月~2019年3月重庆市开州区人民医院确诊的225例离体手术切除标本行组织病理学诊断以为金标准,应用自体荧光内镜检查,与临床病理结果进行对比。结果纳入225例患者,其中经病理学诊断进展期癌203例,早期癌和癌前病变22例;其中鳞癌22例,腺癌150例,重度异型增生1例,印戒细胞癌42例,轻度异型增生1例,神经内分泌癌1例,恶性间质瘤8例。良性病灶17例(横结肠腺瘤性息肉2例、食管糜烂2例、萎缩性胃炎7例、消化道溃疡6例)。本研究所涉及的病变标本:191例呈癌组织特征红色图像,12例未检出分别为:腺癌4例、印戒细胞癌3例、鳞癌3例、恶性间质瘤及轻度异型增生均1例,呈正常特征(绿色)。17例良性标本,15例呈正常特征,2例呈癌组织特征图像(消化道溃疡1例、萎缩性胃炎1例)。自体荧光内镜对于诊断消化道恶性肿瘤和癌前病变总体准确性、敏感性、特异性、阳性预测值和阴性预测值较高,准确性、敏感性、特异性分别为94.7%、95.1%、94.2%,阳性预测值、阴性预测值分别为93.8%、95.6%,自体荧光内镜与组织病理学诊断结果总体一致性较高。结论自体荧光内镜可准确、全面地诊断消化道肿瘤,为消化道肿瘤诊断治疗提供新的依据。