I-scan combined with laryngovideostroboscopy for predicting malignancy in vocal fold leukoplakia.

OBJECTIVE: This study evaluated vocal fold leukoplakia using i-scan combined with laryngovideostroboscopy for risk assessment prediction. METHODS: A total of 141 patients with 218 lesions were enrolled in this study. Morphological characteristics of leukoplakia, assessment of the vascular pattern using i-scan, and vocal fold vibratory function were analyzed. RESULTS: The number of patients with no, mild, moderate, severe dysplasia, and invasive carcinoma were 68, 40, 17, 46 and 47, respectively. The sensitivity of morphological characteristic, vascular pattern, vibratory function and predictive model were 77.4%, 72%, 69.9%, and 82.8%, respectively. Receiver operating characteristic curve analysis of morphological characteristic, vascular pattern, vibratory function and predictive model were 0.771, 0.824, 0.769, and 0.923, respectively. The results of logistic regression analysis showed that rough morphological types, perpendicular vascular pattern, severe decrease and absence of mucosal waves increased the risk of malignancy (OR = 5.531, 4.973, and 16.992, respectively; P < 0.001). CONCLUSIONS: I-scan combined with laryngovideostroboscopy can improve the differential diagnosis of low-risk and high-risk vocal fold leukoplakia.

Endoscopic Advances in the Diagnosis and Management of Gastroesophageal Reflux Disease.

Gastroesophageal reflux disease (GERD) is one of the most common diseases that occurs secondary to failure of the antireflux barrier system, resulting in the frequent and abnormal reflux of gastric contents to the esophagus. GERD is diagnosed in routine clinical practice based on the classic symptoms of heartburn and regurgitation. However, a subset of patients with atypical symptoms can pose challenges in diagnosing GERD. An esophagogastroduodenoscopy (EGD) is the most common initial diagnostic test used in the assessment for GERD, although half of these patients will not have any positive endoscopic findings suggestive of GERD. The advanced endoscopic techniques have improved the diagnostic yield of GERD diagnosis and its complications, such as Barrett's esophagus and early esophageal adenocarcinoma. These newer endoscopic tools can better detect subtle irregularities in the mucosa and vascular structures. The management options for GERD include lifestyle modifications, pharmacological therapy, and endoscopic and surgical interventions. The latest addition to the armamentarium is the minimally invasive endoscopic interventions in carefully selected patients, including the electrical stimulation of the LES, Antireflux mucosectomy, Radiofrequency therapy, Transoral Incisionless Fundoplication, Endoscopic Full-Thickness plication (GERDx™), and suturing devices. With the emergence of these advanced endoscopic techniques, it is crucial to understand their selection criteria, advantages, and disadvantages.

The incremental yield of adenoma detection with I-Scan versus high-definition white light colonoscopy-a systematic review and meta-analysis of randomized studies.

INTRODUCTION: The incremental yield of I-Scan virtual chromoendoscopy compared to high-definition white light endoscopy (HD-WLE) in detection of colorectal adenomas has not been thoroughly elucidated. METHODS: A systematic search from inception to April 2023 was conducted to identify randomized controlled trials (RCTs) comparing I-Scan to HD-WLE for detection of adenomas. A random effects model was used to compute risk difference (RD) with corresponding 95% confidence intervals in adenoma detection rate (ADR). Influence analysis was done to assess robustness of findings. The number needed to diagnose was computed. Heterogeneity was assessed using the I2 statistic and explored further by subgroup analyses defined a priori. Certainty in effect estimates was assessed using the GRADE approach. RESULTS: We identified four studies (I-Scan n = 730, HD-WLE n = 765). I-Scan increased adenoma detection by 9% (risk difference (RD), 0.09; 0.04, 0.14; I2 02%; certainty, low). Influence analysis revealed that the gain in yield remained statistically significant with exclusion of all but one study. The number needed to capture one additional adenomatous polyp with I-Scan use was 11.2. I-Scan 1 use was associated with a statistically significant gain in ADR, whereas no significant difference in ADR was noted with I-Scan use on subgroup analysis. DISCUSSION: In conclusion, I-Scan increases the yield of adenoma detection by 9% compared to HD-WLE, with low certainty in the estimate of this effect. Data on the gain in yield of detecting large polyps, sessile serrated lesions, and on the impact of formally training endoscopists and trainees in I-Scan use and similar technology on adenoma detection rate are needed.

Possible Role of Image-Enhanced Endoscopy in the Evaluation of Mucosal Healing of Ulcerative Colitis.

BACKGROUND: Mucosal healing (MH) is recognized as a therapeutic target in ulcerative colitis (UC) because of evidence that it is associated with favorable clinical outcomes. Current endoscopic assessment of MH by conventional white-light endoscopy is subject to several important clinical issues including the subjective nature of assessment, intra- and interobserver variability, and persistent microscopic inflammation, even in mucosa it was observed as quiescent on conventional endoscopy. SUMMARY: Advances in image-enhancement technologies enable the provision of high-contrast images that emphasize the mucosal structures, blood vessel patterns, and color tones of the intestinal mucosa, and recently, several image-enhanced endoscopy (IEE) techniques have become available for the assessment of MH in UC. Narrow-band imaging and dual-red imaging facilitate visualization of mucosal vascular structures, which is useful for detecting minor inflammation and predicting relapse because of the capturing of information on incomplete vascular regeneration in patients with UC. Linked-color imaging (LCI) is optimized to emphasize the redness of the mucosa and blood vessels, and is superior for depicting subtle color changes arising from mucosal inflammation. LCI could possibly be used to stratify UC patients with MH on conventional endoscopy. Autofluorescence imaging and i-scan can also depict subtle histological changes underlying the healing of mucosa in UC, revealing them as simple color changes. KEY MESSAGES: Accumulating evidence suggests that IEE techniques could overcome current unmet needs in the endoscopic assessment of MH in UC and contribute to improving therapy based on treat-to-target strategies.

Chromoendoscopy for Surveillance in Ulcerative Colitis and Crohn's Disease: A Systematic Review of Randomized Trials.

BACKGROUND & AIMS: Key international guideline agencies recommend dysplasia surveillance in inflammatory bowel diseases with chromoendoscopy. We performed a systematic review of randomized trials comparing chromoendoscopy vs other endoscopic techniques for dysplasia surveillance in inflammatory bowel diseases. METHODS: We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials for relevant studies published through September 2016. We estimated risk ratios (RRs) for dichotomous outcomes (all-cause/colorectal cancer-related mortality, time to interval cancer, patients with dysplasia, total/subtypes of dysplastic lesions, dysplasia detected by targeted biopsies, adverse events), mean differences for continuous outcomes (procedural time, costs, total/targeted biopsies), and their 95% confidence intervals (CIs) using a random-effects model. Subgroup analyses included technique compared with chromoendoscopy, type of disease, and type of dye. We estimated sensitivity and specificity of the techniques with reference to histology. RESULTS: We identified 10 randomized trials (n = 1500 participants). There was a higher likelihood of detecting patients with dysplasia with chromoendoscopy compared with other techniques (RR, 1.37; 95% CI, 1.04-1.79). Subgroup analyses confirmed this effect only if chromoendoscopy was compared with standard-definition white-light endoscopy (RR, 2.12; 95% CI, 1.15-3.91). Chromoendoscopy required a significantly longer procedural time compared with other techniques (mean difference, 8.91 min; 95% CI, 1.37-16.45). There was no difference in the likelihood of detecting dysplastic subtypes and dysplasia by targeted biopsies between groups. Test sensitivity and specificity were similar between groups. CONCLUSIONS: In surveillance of inflammatory bowel diseases, chromoendoscopy identifies more patients with dysplasia only when compared with standard-definition white-light endoscopy. It is associated with longer procedural time with no direct evidence of effect on preventing all-cause/cancer-specific mortality or time to interval cancer.

[Novel imaging methods in endoscopic diagnosis of gastrointestinal tumors]. / Nové zobrazovací metody v endoskopické diagnostice nádoru trávicího ústrojí.

Advances in imaging, digitization and all kinds of technologies result in development of potentially efficient imaging modalities, which enable magnification to subcellular levels, color differentiation and observation of pathophysiological processes. NBI, FICE, I-scan and KFE are new commercially available modalities.NBI is the most explored one. Its contribution has been shown in diagnosis of Barrett's neoplasia and esophageal squamous cell carcinoma and in characterization of early stomach cancer. It enables rather accurate characterization of changes in adenomatous colonic polyps; however it is not used for this purpose in clinical practice. It can demonstrate atrophy of small bowel mucosa in celiac disease, but it is not able to evaluate intraepithelial lymphocytosis. Its contribution in dysplasia detection in inflammatory bowel disease is not significant; chromoendoscopy remains the gold standard.The use of CFE remains experimental; the routine use is limited also due to its high cost.

White Paper AGA: Advanced Imaging in Barrett's Esophagus.

Enhanced imaging technologies such as narrow band imaging, flexible spectral imaging color enhancement, i-Scan, confocal laser endomicroscopy, and optical coherence tomography are readily available for use by endoscopists in routine clinical practice. In November 2014, the American Gastroenterological Association's Center for GI Innovation and Technology conducted a 2-day workshop to discuss endoscopic image enhancement technologies, focusing on their role in 2 specific clinical conditions (colon polyps and Barrett's esophagus) and on issues relating to training and implementation of these technologies (white papers). Although the majority of the studies that use enhanced imaging technologies have been positive, these techniques ideally need to be validated in larger cohorts and in community centers. As it stands today, detailed endoscopic examination with high-definition white-light endoscopy and random 4-quadrant biopsy remains the standard of care. However, the workshop panelists agreed that in the hands of endoscopists who have met the preservation and incorporation of valuable endoscopic innovation thresholds (diagnostic accuracy) with enhanced imaging techniques (specific technologies), use of the technique in Barrett's esophagus patients is appropriate.

Advanced endoscopic imaging: a review of commercially available technologies.

The rapid strides made in innovative endoscopic technology to improve mucosal visualization have revolutionized endoscopy. Improved lesion detection has allowed the modern endoscopist to provide real-time optical diagnosis. Improvements in image resolution, software processing, and optical filter technology have resulted in the commercial availability of high-definition endoscopy as well as optical contrast techniques such as narrow-band imaging, flexible spectral imaging color enhancement, and i-scan. Along with autofluorescence imaging and confocal laser endomicroscopy, these techniques have complemented and enhanced traditional white light endoscopy. They have the potential to serve as red-flag techniques to improve detection of mucosal abnormalities as well as allow optical diagnosis and virtual histology of detected lesions. This review will focus on these emerging commercially available technologies and aims to provide an overview of the technologies, their clinical applicability, and current status.

Present and future perspectives of virtual chromoendoscopy with i-scan and optical enhancement technology.

Despite being the current gold standard, white-light endoscopy may miss a significant proportion of lesions within the colorectum, thus leading to a misinterpretation of various disease findings. Traditionally, dye-based chromoendoscopy is used to improve both detection and characterization of lesions during luminal gastrointestinal (GI) endoscopy. Recently introduced dye-less chromoendoscopy (DLC) techniques have overcome many of the limitations of dye-based chromoendoscopy, thereby potentially improving lesion recognition and characterization. In detail, DLC techniques allow for better detection of esophageal lesions, gastric cancer and colorectal pathologies including colorectal polyps and inflammatory bowel diseases. Moreover, DLC techniques enable a more precise characterization of lesions throughout the whole luminal GI tract, thereby potentially enabling more accurate endoscopic therapies. In the present review we focus on the newly introduced dye-less chromoendoscopy technique i-scan and give an additional outlook on the recent development of optical enhancement technology.

The Application of I-Scan Imaging for Evaluating Benign Vocal Lesions.

Current standard methods for evaluating benign vocal lesions, including white light laryngoscopy and video laryngostroboscopy, may struggle to identify smaller lesions. While histopathological results obtained from laryngeal microsurgery provide definitive results, their invasiveness can lead to scarring and impaired phonological outcomes. Intralesional steroid injection has recently gained acceptance, but it lacks pathological diagnostic capabilities. Therefore, there is a growing need for a simple examination that can enhance the diagnosis of benign vocal lesions. NBI, from Olympus Corporation, has shown promising outcomes in detecting and characterizing laryngeal lesions. The i-scan technology by PENTAX, while providing the ability to improve visual clarity during endoscopic procedures, has been addressed less in this field. Our study aims to further investigate the application of i-scan imaging in benign vocal lesions, enrolling patients diagnosed with vocal cysts, polyps, and nodules. We conducted i-scan imaging prior to office-based intralesional steroid injection, assessing the possibility of its providing additional diagnostic information for benign vocal lesions without additional burden.

A prospective study for evaluating the effect of gastric targeted biopsy sampling with I-scan optical enhancement on the diagnostic yield of CLOtest for Helicobacter pylori infection.

Background and Aim of the Work: Helicobacter pylorigastritis can cause serious adverse effects in the short and long term. I-scan optical enhancement (OE) has a potential role to distinguish areas of infected mucosa and allow for targeted biopsy. It improves visual contrast and mucosal pattern characterization. The work aims to determine if the diagnostic yield of the CLOtest could be improved by using endoscopic I-scan OE technology for targeted gastric biopsy sampling. Patients and Methods: A prospective study recruited 112 adult patients with active H. pylori infection diagnosed by C13 UBT at Nizwa General Hospital from March 2021 to January 2022. The patients underwent a careful examination by nonmagnifying upper endoscopy and I-scan OE 3 moods, then randomly allocated into two groups. Group A: nontargeted double biopsies from the antrum and mid corpus. Group B: I-scan OE-directed targeted biopsy from abnormal mucosal patterns. The biopsy specimens were inoculated into CLOtest kits; the reading time of the positive results was at 1, 4, and 24 h. Results: Group B had a 92.8% positive CLOtest compared to 89.3% in group A (p = 0.501). One-hour CLOtest was positive in 78.5% of the patients in group B compared to 60.7% in group A (p = 0.047), while group A had a significantly more positive CLOtest at 24 h. Conclusion: Sampling a targeted gastric biopsy with the aid of I-scan -OE for CLOtest significantly hastens the positive reading time with high sensitivity.

Reflux Finding Score Using HD Video Chromoendoscopy: A Diagnostic Adjunct in Suspected Laryngopharyngeal Reflux?

OBJECTIVE: To explore the use of real-time virtual chromoendoscopy (i-scan) in characterizing the mucosal changes present in subjects with suspected laryngopharyngeal reflux (LPR) and to compare the inter-rater and intra-rater agreement of Reflux Finding Scores (RFS) from both laryngologists and general otolaryngologists (ORL) observing exams using both white light endoscopy (WLE) and i-scan. METHODS: This is a cross-sectional study that included 66 subjects: 46 symptomatic and 20 asymptomatic of suspected LPR based on the reflux symptom index (RSI). Subjects underwent flexible video laryngoscopic evaluation of the larynx utilising both WLE and i-scan during one continuous exam. Subjects also underwent 24-hour oropharyngeal pH-monitoring (Dx-pH). Two laryngologists and two general otolaryngologists evaluated the anonymized videos independently using RFS. Dx-pH results were interpreted using the pH graph, report and RYAN score. Subjects were then designated into one of three groups: no reflux, acid reflux and alkaline reflux. RESULTS: For the symptomatic group, no mucosal irregularities or early mucosal lesions were observed except in one subject who had granulation tissue. The mean RFS using WLE and i-scan were, respectively: 11.8 (SD 6.1) and 11.3 (SD 5.6) in symptomatic and 7.3 (SD 5.7) and 7.3 (SD 5.2) in asymptomatic group. The inter-rater agreement of RFS using WLE and i-scan for both groups were good with intraclass correlation, ICC of 0.84 and 0.88 (laryngologists); and 0.85 and 0.81 (ORL). The intra-rater agreement among all four raters were good to excellent and similar for both WLE and i-scan (ICC of 0.80 to 0.99). 47 of 66 subjects had evidence of LPR on Dx-pH results which more specifically showed 39 subjects had "acid reflux" and 8 had "alkaline reflux". Sixteen subjects demonstrated a positive RYAN score but showed none were significantly correlated with their RFS. CONCLUSIONS: This study reports the first utilization of real-time video chromoendoscopy with i-scan technology through high-definition flexible endoscopes to attempt to characterize laryngopharyngeal findings in patients suspected of having LPR. Both general otolaryngologists and laryngologists were equally capable of reliably calculating the RFS using both WLE and i-scan, however no significant improvement in agreement or change in RFS was found when i-scan technology was employed. LEVEL OF EVIDENCE: Level 2.

Comparison of the effectiveness of i-scan and conventional endoscopy in the detection of the endoscopic signs of atrophic gastritis: A clinical trial.

BACKGROUND AND STUDY AIMS: This study aimed to determine whether the use of i-scan endoscopy provides additional benefits to conventional endoscopy in the diagnosis of gastric precancerous lesions. PATIENTS AND METHODS: A total of 120 patients with histologically-verified intestinal metaplasia (IM) or atrophic gastritis (AG) were prospectively evaluated by esophagogastroduodenoscopy. Endoscopic examinations were performed using i-scan and high-definition white-light endoscopy (HD-WLE). The diagnostic yields of both techniques and the number of targeted biopsies per patient were compared. RESULTS: A total of 318 suspicious lesions were detected in 108 patients with i-scan (n = 186) and 81 patients with HD-WLE (n = 132). The diagnostic yields of i-scan and HD-WLE were 81.6% (98/120) versus 77.5% (93/120), respectively (p > 0.05). When only targeted biopsies were taken into account, the diagnostic yields of i-scan and HD-WLE were 89.8% versus 65.4%, respectively (p < 0.05). The mean number of biopsies per patient for i-scan and HD-WLE were 3.27 (393/120) and 7.3 (882/120), respectively (p < 0.05). The mean endoscopic procedure times were 16 and 17 min for i-scan and HD-WLE, respectively (p > 0.05). CONCLUSIONS: Although targeted biopsies with i-scan were not found to be significantly superior to either targeted or random biopsies with HD-WLE, the number of biopsies required to confirm these lesions was much lower.

Electronic chromo-endoscopy: technical details and a clinical perspective.

Precise endoscopic assessment is necessary to detect neoplastic changes in an early stage. Electronic or virtual chromo-endoscopy (ECE) is an alternative to conventional dye-based chromo-endoscopy which markedly improves capillary pattern and hence can detect micro-vessel morphological changes of early neoplasia to target biopsies and aid in diagnosis. The clinical significance increased after the advent of endoscopic treatment modalities like ESD/EMR which requires precise delineation of extent and depth of lesion. Most of the studies have used narrow-band imaging (NBI) (Olympus Medical Systems Tokyo, Japan), although data from i-SCAN (PENTAX Endoscopy, Tokyo, Japan) and flexible spectral imaging color enhancement (FICE) (Fujinon, Fujifilm Medical Co, Saitama, Japan) are emerging. Electronic chromo-endoscopy is convenient compared to dye-based chromo-endoscopy in the sense that it is available at the push of a button in endoscope and reduces procedure time substantially with comparable efficacy. Scope of this review is to discuss available electronic chromo-endoscopy modalities and their role in the diagnosis, surveillance, and management of early GI neoplasia.

Comparative Study of Narrow-Band Imaging and i-scan for Predicting the Histology of Intermediate-to-Large Colorectal Polyps: A Prospective, Randomized Pilot Study.

BACKGROUND/AIMS: To date, no reports have compared the diagnostic efficacy of narrow-band imaging (NBI) and i-scan for the histologic prediction of intermediate-to-large colorectal polyps. We aimed to compare the diagnostic accuracy of NBI and i-scan in predicting histology, and their inter-/intra-observer agreement. METHODS: We performed a prospective, randomized study that included 66 patients (NBI, n=33 vs. i-scan, n=33) with colorectal polyps (size >10 mm but <50 mm) who underwent colonoscopic resection. During the procedure, three endoscopists documented their prediction using the Japan NBI Expert Team (JNET) classification. Two months after study completion, the endoscopists reviewed still images and video clips for analysis. RESULTS: The overall diagnostic accuracies in the NBI and i-scan groups were 73.7% (73/99) and 75.8% (75/99), respectively, and there was no statistical significance between the two groups (p=0.744). The JNET classification as applied to NBI and i-scan showed substantial inter-observer agreement (NBI κ-value 0.612, p=0.001 vs. i-scan κ-value 0.662, p=0.002). Additionally, the κ-values of intra-observer agreement were in the range of 0.385-0.660 with NBI and 0.364-0.741 with i-scan. CONCLUSION: NBI and i-scan have similar diagnostic accuracies for the histologic prediction of intermediate-to-large colorectal polyps. Furthermore, the inter-/intra-observer agreement was acceptable for both modalities when the JNET classification was applied.

Endoscopic Advances for Gastric Neoplasia Detection.

This article explores advances in endoscopic neoplasia detection with supporting clinical evidence and future aims. The ability to detect early gastric neoplastic lesions amenable to curative endoscopic submucosal dissection provides the opportunity to decrease gastric cancer mortality rates. Newer imaging techniques offer enhanced views of mucosal and microvascular structures and show promise in differentiating benign from malignant lesions and improving targeted biopsies. Conventional chromoendoscopy is well studied and validated. Narrow band imaging demonstrates superiority over magnified white light. Autofluorescence imaging, i-scan, flexible spectral imaging color enhancement, and bright image enhanced endoscopy show promise but insufficient evidence to change current clinical practice.

124I Positron Emission Tomography/Computed Tomography Versus Conventional Radioiodine Imaging in Differentiated Thyroid Cancer: A Review.

Background: Studies report a wide spectrum of 124I positron emission tomography (PET)/computed tomography (CT) sensitivity and specificity in the detection of differentiated thyroid cancer (DTC) lesions. This study reviews the lesion detection rate of pretherapy 124I PET/CT in different patient populations and further analyzes the factors necessary for a better detection on 124I PET/CT. Methods: A literature search was performed using multiple different databases (MEDLINE, EMBASE, Northern Lights, and handsearching) covering 1996 to April 2018. Two reviewers reviewed and extracted study data for 124I, 123I, and 131I scans in DTC. Results: This review includes 4 retrospective and 10 prospective studies in which 495 DTC patients underwent 124I and 131I imaging; no studies made comparisons with 123I. In the reports that compared 124I PET/CT with diagnostic 131I scans, there were a total of 72 patients in whom 120 lesions were detected on 124I imaging, whereas only 52 were detected on diagnostic 131I scans. In publications that compared 124I with post-therapy 131I scans in 266 patients, 410 lesions were detected with 124I PET, whereas 390 were detected on post-therapy 131I scans. Based on 124I PET/CT in six studies, TNM staging was revised in 15-21% of patients, and disease management was altered in 5-29% of patients. Conclusions:124I PET/CT is able to identify a greater number of foci compared with diagnostic 131I scans. 124I PET may have better detection compared with post-therapy 131I scans in patients who are 131I therapy naive, have less aggressive pathology, or do not have disseminated lung metastases. Additional metastatic lesion detection by 124I PET may have a significant clinical impact in the management of patients before 131I therapy in some patients.

Clinical Significance of Diminutive Colonic Polyps in Elderly Patients.

BACKGROUND AND OBJECTIVES: Colorectal cancer is the third leading cause of cancer-related death. Excision of premalignant polyps has a significant impact on reducing colorectal cancer mortality and morbidity. Colonoscopy is considered to be the gold standard for the diagnosis and affords an opportunity for treatment of colonic polyps. In recent years, serious debates have taken place because of the biological characteristics of diminutive polyps (DPs), polypectomy complications, and serious costs. There has not yet been a consensus on the management of DPs. The objectives of this study were to demonstrate the real clinical importance of DPs smaller than 5 mm in diameter, which are frequently seen in geriatric patients by new endoscopic techniques, and to help in determining screening and surveillance programs. METHODS: The patients who underwent colonoscopy and were found to have a diminutive colorectal polyp (<5 mm from September 1, 2016 through September 1, 2017), were classified into 3 groups according to the imaging method used: flexible spectral imaging color enhancement (FICE), narrow band imaging (NBI), or I-SCAN. In all groups, demographic data were compared according to Paris classification (morphologic) and Kudo classification (correlation between the prediction of endoscopic diagnosis and final pathological examination) in terms of sensitivity, specificity, and negative and positive predictive values. RESULTS: Two hundred sixty-seven patients were included in the study: 97 in the NBI group, 83 in the FICE group, and 87 in the I-SCAN group. There were no statistically significant differences between NBI, FICE, and I-SCAN in differentiating neoplastic and nonneoplastic polyps, according to the Kruskal-Wallis test (P = .809). CONCLUSIONS: The estimated progression rates of DPs to advanced adenomas or colorectal cancer (CRC) are very low. Missing these polyps or not excising them may lead to failure to diagnose some cancers. There is a need for further comprehensive studies of removing all polyps to determine whether non-high-risk lesions require further pathologic examination and to re-examine routine surveillance programs.

Detection and characterization of colorectal polyps using high-definition white light and i-Scan: Evidence-based consensus recommendations using a modified Delphi process.

BACKGROUND: i-Scan is an image enhancement modality, which provides enhanced views of mucosal structures and vascular patterns. METHODS: A modified Delphi process was used to develop a series of evidence-based statements on the role of high-definition white light (HDWL) and i-Scan for the detection and diagnosis of colorectal neoplasms. Each statement was voted to achieve consensus (i.e. >80% agreement). RESULTS: Seven proposed statements achieved consensus: (1) HDWL is recommended rather than standard definition (SD) for detection and diagnosis of colorectal neoplasms; (2) HDWL colonoscopy with i-Scan improves polyp and adenoma detection rates when compared with SD colonoscopy; (3) HDWL + i-Scan is superior to HDWL alone for the optical diagnosis of colorectal neoplasms; (4) HDWL + i-Scan in expert hands meets American Society for Gastrointestinal Endoscopy (ASGE) in the Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) standards for optical diagnosis of diminutive neoplasms; (5) HDWL + i-Scan in non-expert hands does not meet ASGE PIVI standards for optical diagnosis of diminutive neoplasms; (6) optical diagnosis of polyps with i-Scan has a learning curve and needs systematic training; and (7) the performance of i-Scan for the in vivo diagnosis of colorectal neoplasms is similar to Narrow Band Imaging (NBI) and Fuji Intelligent Chromo Endoscopy (FICE). CONCLUSIONS: Seven proposed statements on the use of HDWL and i-Scan for the detection and diagnosis of colorectal neoplasms achieved consensus.

Diagnostic accuracy of i-scan image enhancement for real-time endoscopic diagnosis of small colorectal polyps: a meta-analysis.

OBJECTIVE: i-Scan is a digital image enhancement technology, reported to improve diagnostic performance during endoscopy. Previous studies have investigated the accuracy of i-scan for distinguishing between neoplastic and non-neoplastic colonic polyps and suggested diagnostic accuracy close to that required for use in routine clinical practice. The aim of this study was to perform a meta-analysis of the available literature investigating diagnostic accuracy for i-scan optical diagnosis when made in real time for colorectal polyps <10 mm in size. DATA SOURCES: The databases of Medline, Embase and the Cochrane Library were searched for relevant studies. METHODS: A bivariate random effects model was used to produce pooled sensitivity and specificity values, and univariable meta-regression was applied for subgroup analysis. RESULTS: The meta-analysis included 15 studies, and diagnosis of 2817 polyps. The area under the hierarchical summary receiver-operating characteristic curve was 0.96. The pooled sensitivity of i-scan optical diagnosis was 0.92 (95% confidence interval 0.85-0.95). The specificity was 0.90 (95% confidence interval 0.83-0.94). CONCLUSIONS: This meta-analysis updates and summarizes the available evidence concerning the diagnostic performance of i-scan for small colorectal polyps. An acceptable degree of accuracy was found, showing potential to support a 'resect and discard' strategy for colonic polyps. There was not found to be a significant difference in diagnostic performance between different clinical settings (i.e. teaching hospitals or general hospitals).