Clinical utility of capsule endoscopy with flexible spectral imaging color enhancement for diagnosis of small bowel lesions

Prospective study of diagnostic yields of flexible spectral imaging color enhancement installed in colon capsule endoscopy for colorectal polyps and tumors

BACKGROUND AND AIMS

We prospectively determined the efficacy of flexible spectral imaging color enhancement (FICE) used with second-generation colon capsule endoscopy (CCE) for colorectal polyps and tumors (CRTs).

METHODS

This study included optical colonoscopy within 4 months after CCE. Two colonoscopists independently reviewed CCE using white-light images (CCE-WL) and CCE using FICE images (CCE-FICE), respectively. Based on colonoscopic findings as the criterion standard, the diagnostic accuracy for CRTs was compared between CCE-WL and CCE-FICE.

RESULTS

Of 89 enrolled patients (65 men and 24 women; 75 with CRTs including 36 with serrated lesions, 63 with adenomas, and 9 with adenocarcinomas), the per-patient detectability of CCE-FICE for the representative CRTs was significantly higher than that of CCE-WL: overall CRTs (CCE-WL, 79%; CCE-FICE, 88%; P = .0001), 6- to 9-mm CRTs (CCE-WL, 63%; CCE-FICE, 94%; P = .0055), and ≥6-mm CRTs (CCE-WL, 78%; CCE-FICE, 93%; P = .0159). The per-lesion sensitivity of CCE-FICE was significantly higher than that of CCE-WL for CRTs: overall (CCE-WL, 61%; CCE-FICE, 79%; P < .0001), <6 mm (CCE-WL, 53%; CCE-FICE, 69%; P < .0001), 6- to 9-mm CRTs (CCE-WL, 65%; CCE-FICE, 93%; P = .0007), slightly elevated CRTs (CCE-WL, 53%; CCE-FICE, 75%; P < .0001), tubular adenomas (CCE-WL, 61%; CCE-FICE, 79%; P < .0001), and serrated polyps (CCE-WL, 57%; CCE-FICE, 74%; P = .0022). Both modes detected all adenocarcinomas. No significant differences were found between CCE-WL and CCE-FICE of the per-lesion sensitivity for ≥10-mm CRTs (CCE-WL, 81%; CCE-FICE, 94%; P = .1138) or protruding CRTs (CCE-WL, 77%; CCE-FICE, 86%; P = .0614). Kappa coefficients for overall CRTs for CCE-WL and CCE-FICE were .66 and .64, respectively, which indicated substantial agreement.

CONCLUSIONS

CCE-FICE improved the detection rates for all CRTs except adenocarcinomas, ≥10-mm polyps, and protruding polyps when compared with CCE-WL. (Clinical trial registration number: UMIN 000021125.).

Differences in color between early gastric cancer and cancer-suspected non-cancerous mucosa on linked color imaging

Background and study aims  Linked color imaging (LCI) can enhance the original color of each area and may useful to detect tumorous lesions during esophagogastroduodenoscopy. However, LCI may also enhance cancer-suspected non-cancerous regional color change. We conducted a retrospective image analysis to investigate the color characteristics of early gastric cancer (EGC) and cancer-suspected non-cancerous mucosa (CSM) in LCI. Methods  LCI images of both EGC and CSM were retrospectively collected from the database of the institution. Fifteen endoscopists individually judged each image as EGC or CSM. The color difference between the inside and outside of the lesions was measured by CIE-Lab analysis in both groups and compared. Results  A total of 245 LCI images of EGC (169) and CSM (76) were extracted and randomly lined for image collection. The test by the endoscopists showed accuracy, sensitivity, and specificity of 64.0 %, 63.7 %, and 64.0 %, respectively. Although the color difference between EGC and CSM was almost the same (12.5 vs. 12.9, not significant), each parameter of ΔL (bright: -0.3 vs. -2.7, P  < 0.001), Δa (Reddish: 7.2 vs. 9.6, P  = 0.004), and Δb (Yellowish: 6.4 vs. 3.8, P  < 0.001) was significantly different in the groups. The color feature of both positive ΔL and Δb to EGC showed accuracy, sensitivity, and specificity of 54.7 %, 39.6 %, 88.2%, respectively. Conclusions  The total color difference was almost the same between EGC and CSM; however, their color tones were different on linked color imaging. Although the color characteristics of EGC had high specificity, they also had low sensitivity.

Third-Generation High-Vision Ultrathin Endoscopy Using Texture and Color Enhancement Imaging and Narrow-Band Imaging to Evaluate Barrett's Esophagus

It remains unclear whether texture- and color-enhancement imaging (TXI) and narrow-band imaging (NBI) provide an advantage over white-light imaging (WLI) in Barrett’s esophagus. We compared endoscopic findings and color differences between WLI and image-enhanced endoscopy (IEE) using a third-generation ultrathin endoscope. We retrospectively enrolled 40 patients who evaluated Barrett’s esophagus using WLI, TXI, and NBI. Color differences determined using the International Commission on Illumination 1976 (L∗, a∗, b∗) color space among Barrett’s epithelium, esophageal, and gastric mucosa were compared among the endoscopic findings. As the secondary outcome, we assessed the subjective visibility score among three kinds of endoscopic findings. The prevalence of Barrett’s esophagus and gastroesophageal reflux disease (GERD) in WLI was 82.5% and 47.5%, respectively, and similar among WLI, TXI, and NBI. Color differences between Barrett’s epithelium and esophageal or gastric mucosa on NBI were significantly greater than on WLI (all p < 0.05). However, the color difference between Barrett’s epithelium and esophageal mucosa was significantly greater on NBI than TXI (p < 0.001), and the visibility score of Barrett’s epithelium detection was significantly greater on TXI than NBI (p = 0.022), and WLI (p = 0.016). High-vision, third-generation ultrathin endoscopy using NBI and TXI is useful for evaluating Barrett’s epithelium and GERD compared with WLI alone.

Using texture and colour enhancement imaging to evaluate gastrointestinal diseases in clinical practice: a review

White light imaging (WLI) is the most common endoscopic technique used for screening of gastrointestinal diseases. However, despite the advent of a new processor that offers sufficient clear illumination and other advanced developments in endoscopic instrumentation, WLI alone is inadequate for detecting all gastrointestinal diseases with abnormalities in mucosal discoloration and morphological changes to the mucosal surface. The recent development of image-enhanced endoscopy (IEE) has dramatically improved the detection of gastrointestinal diseases. Texture and colour enhancement imaging (TXI) is a new type of IEE that enhances brightness, surface irregularities, such as elevations or depressions, and subtle colour changes. TXI with two modes, namely modes 1 and 2, can selectively enhance brightness in dark areas of an endoscopic image and subtle tissue differences such as slight morphological or colour changes while simultaneously preventing over-enhancement. Several clinical studies have investigated the efficacy of TXI for detecting and visualizing gastrointestinal diseases, including oesophageal squamous cell carcinoma (ESCC), Barret's epithelium, gastric cancer, gastric mucosal atrophy and intestinal metaplasia. Although TXI is often more useful for detecting and visualizing gastrointestinal diseases than WLI, it remains unclear whether TXI outperforms other IEEs, such as narrow-band imaging (NBI), in similar functions, and whether the performance of TXI modes 1 and 2 are comparable. Therefore, large-scale prospective studies are needed to compare the efficacy of TXI to WLI and other IEEs for endoscopic evaluation of patients undergoing screening endoscopy. Here, we review the characteristics and efficacy of TXI for the detection and visualization of gastrointestinal diseases.Key MessagesTXI mode 1 can improve the visibility of gastrointestinal diseases and qualitative diagnosis, especially for diseases associated with colour changes.The enhancement of texture and brightness with TXI mode 2 enables the detection of diseases, and is ideal for use in the first screening of gastrointestinal tract.

Efficacy of high-vision transnasal endoscopy using texture and colour enhancement imaging and narrow-band imaging to evaluate gastritis: a randomized controlled trial

BACKGROUND

A new image-enhanced endoscopy method called texture and colour enhancement imaging (TXI) enhances brightness, surface irregularities, and subtle colour changes in endoscopic images. However, it is unclear whether TXI and narrow-band imaging (NBI) with third-generation high-vision transnasal ultrathin endoscopy are advantageous over white-light imaging (WLI) for detecting atrophy, intestinal metaplasia, map-like redness and gastric cancer. We investigated to compare the endoscopic efficacy for evaluation of gastritis between TXI and NBI with high-vision transnasal endoscopy and clarified the endoscopic efficacy of TXI and NBI compared to WLI.

METHODS

We enrolled 60 patients who underwent high-vision transnasal endoscopy as part of a health check-up from March to November 2021 and randomized patients into two groups (the WLI-NBI group and the WLI-TXI group) using the minimization method based on Helicobacter pylori infection status, age and sex. Colour differences determined using the International Commission on Illumination 1976 (L∗, a∗, b∗) colour space was compared between WLI and TXI or NBI.

RESULTS

No significant differences were observed in colour differences surrounding atrophy, intestinal metaplasia and map-like redness between NBI and TXI (p = .553, .057 and .703, respectively). Endoscopic scores based on the Kyoto classification of gastritis for atrophy, intestinal metaplasia, and map-like redness were similar between WLI and TXI. In contrast, NBI identified intestinal metaplasia at a significantly greater rate than WLI (p = .018). Further, colour differences surrounding atrophy and intestinal metaplasia on TXI and NBI were significantly greater than those on WLI (atrophy: TXI vs WLI p = .003, NBI vs WLI p < .001; intestinal metaplasia: TXI vs WLI p = .016, NBI vs WLI p < .001). However, TXI and NBI were not advantageous over WLI for detecting map-like redness.

CONCLUSION

Third-generation high-vision transnasal ultrathin endoscopy using TXI and/or NBI is useful for detecting atrophic borders and intestinal metaplasia.Key MessagesHigh-vision transnasal endoscopy using TXI or NBI is useful for diagnosing and detecting atrophy and intestinal metaplasia.TXI and NBI increase colour differences surrounding atrophy and intestinal metaplasia, thereby increasing diagnostic efficiency to improve risk stratification for gastric cancer.The image quality and detection rate have improved markedly with the latest ultrathin high-vision transnasal endoscopes.

Virtual Chromoendoscopy in Capsule Endoscopy: A Narrative Review

The usefulness of virtual chromoendoscopy (VC) in capsule endoscopy (CE) isa controversial issue, with conflicting studies regarding its efficacy. FICE and a blue filter were embedded in the PillCamTM software, with the aim to assist readers in identifying the source of obscure gastrointestinal (GI) bleeding (OGIB), coeliac disease mucosal changes and other small and large bowel lesions, including polyps and tumors. This review aims to summarize the existing evidence on the value of VC in the visualization and identification of different types of pathology. Overall, VC in CE with FICE 1 and 2 can be a useful adjunctive tool and may increase the visibility of pigmented lesions, such as angiectasias and ulcers. However, it does not appear to improve the detection of polyps or tumors. On the other hand, the role of FICE 3 and the blue filter appears to be limited. FICE may also be helpful in differentiating hyperplastic and adenomatous colonic polyps during colon capsule endoscopy, although more evidence is needed.

Efficacy of a Third-Generation High-Vision Ultrathin Endoscope for Evaluating Gastric Atrophy and Intestinal Metaplasia in Helicobacter pylori-Eradicated Patients

BACKGROUND

Image-enhanced endoscopy methods such as narrow-band imaging (NBI) are advantageous over white-light imaging (WLI) for detecting gastric atrophy, intestinal metaplasia, and cancer. Although new third-generation high-vision ultrathin endoscopes improve image quality and resolution over second-generation endoscopes, it is unclear whether the former also enhances color differences surrounding atrophy and intestinal metaplasia for endoscopic detection. We compared the efficacy of a new third-generation ultrathin endoscope and an older second-generation endoscope.

METHODS

We enrolled 50 Helicobacter pylori-eradicated patients who underwent transnasal endoscopy with a second-generation and third-generation endoscope (GIF-290N and GIF-1200N, respectively) in our retrospective study. Color differences based on the International Commission on Illumination 1976 (L*, a*, b*) color space were compared between second-generation and third-generation high-vision endoscopes.

RESULTS

Color differences surrounding atrophy produced by NBI on the GIF-1200N endoscope were significantly greater than those on GIF-290N (19.2 ± 8.5 vs. 14.4 ± 6.2, p = 0.001). In contrast, color differences surrounding intestinal metaplasia using both WLI and NBI were similar on GIF-1200N and GIF-290N endoscopes. NBI was advantageous over WLI for detecting intestinal metaplasia on both endoscopes.

CONCLUSIONS

NBI using a third-generation ultrathin endoscope produced significantly greater color differences surrounding atrophy and intestinal metaplasia in H. pylori-eradicated patients compared with WLI.

Linked color imaging effectively detects the endoscopic atrophic border in transnasal endoscopy

In oral endoscopy, linked color imaging (LCI) detects atrophic border and gastric mucosal diseases better than white light imaging (WLI), but its usefulness in transnasal endoscopy has not been fully investigated. Here, we retrospectively compared WLI and LCI using the L*a*b* color space in images from 57 patients aged ≥20 years who had undergone transnasal endoscopy as part of a health check-up from May 2016 to January 2017. We measured color differences at the atrophic/non-atrophic and fundic/pyloric mucosal borders. Gastritis severity scored using the Kyoto classification of gastritis was similar between the two techniques. However, in patients with current and with past Helicobacter pylori infection, color difference at the atrophic border was greater with LCI (21.58 ± 6.97 and 27.34 ± 10.32, respectively) than with WLI [14.42 ± 5.95 (p = 0.004) and 17.9 ± 8.48 (p<0.001)]; in those never infected with Helicobacter pylori, color difference at the fundic/pyloric mucosal border was greater with LCI than with WLI (p<0.001). Because of its enhancement of atrophic border detection, we recommend linked color imaging as the method of choice for transnasal endoscopy in health check-ups, particularly for identifying people at high risk of gastric cancer.

Image-Enhanced Capsule Endoscopy Improves the Identification of Small Intestinal Lesions

Image-enhanced endoscopy is useful for diagnosing and identifying lesions in the gastrointestinal tract. Recently, image-enhanced endoscopy has become a breakthrough technology that has attracted significant attention. This image enhancing technology is available for capsule endoscopy, which is an effective tool for small intestinal lesions and has been applied in flexible spectral color enhancement technology and in contrast capsule like narrow-band imaging. In this field, most researchers focus on improving the visibility and detection of small intestinal lesions. This review summarizes previous studies on image-enhanced capsule endoscopy and aims to evaluate the efficacy of this technology.

The Differential Diagnosis of Colorectal Polyps Using Colon Capsule Endoscopy

Objective Although colorectal polyps (CPs) can be observed with colon capsule endoscopy (CCE), it is difficult to determine the type of polyp using CCE. The objective of this study was to differentiate adenomatous polyps (APs) from hyperplastic polyps (HPs) with CCE. Methods In this single-center retrospective study, an analysis was conducted on the same CPs with both CCE and colonoscopy (CS) and histopathologically diagnosed as AP or HP. The color difference (ΔE) between the polyp surface and the surrounding mucosa was calculated using the CIE1976 L*a*b* color space method on white light (WL), flexible spectral imaging color enhancement (FICE), and blue mode (BM) CP images. We investigated the ability of the ratio of the color differences (ΔE') to differentiate between APs and HPs. Results The size of all 51 polyps (34 APs, 17 HPs) was 7.5±4.6 mm with CCE and 7.3±4.2 mm with CS, and this difference was not significant (p=0.28). The FICEΔE' of APs was 3.3±1.8, which was significantly higher than the FICEΔE' of HPs (1.3±0.6; p<0.001). A receiver operating characteristic analysis showed that FICEΔE' was useful for differentiating between APs and HPs, with an area under the curve of 0.928 (95% confidence interval, 0.843-1). The sensitivity was 91.2%, and the specificity was 88.2% with a cut-off value of 1.758. Conclusion Using FICE on CCE images of CPs and applying the CIELAB color space method, we were able to differentiate between APs and HPs with high accuracy. This method has the potential to reduce unnecessary CS procedures.

Efficacy of Texture and Color Enhancement Imaging in visualizing gastric mucosal atrophy and gastric neoplasms

In 2020, Olympus Medical Systems Corporation introduced the Texture and Color Enhancement Imaging (TXI) as a new image-enhanced endoscopy. This study aimed to evaluate the visibility of neoplasms and mucosal atrophy in the upper gastrointestinal tract through TXI. We evaluated 72 and 60 images of 12 gastric neoplasms and 20 gastric atrophic/nonatrophic mucosa, respectively. The visibility of gastric mucosal atrophy and gastric neoplasm was assessed by six endoscopists using a previously reported visibility scale (1 = poor to 4 = excellent). Color differences between gastric mucosal atrophy and nonatrophic mucosa and between gastric neoplasm and adjacent areas were assessed using the International Commission on Illumination L*a*b* color space system. The visibility of mucosal atrophy and gastric neoplasm was significantly improved in TXI mode 1 compared with that in white-light imaging (WLI) (visibility score: 3.8 ± 0.5 vs. 2.8 ± 0.9, p < 0.01 for mucosal atrophy; visibility score: 2.8 ± 1.0 vs. 2.0 ± 0.9, p < 0.01 for gastric neoplasm). Regarding gastric atrophic and nonatrophic mucosae, TXI mode 1 had a significantly greater color difference than WLI (color differences: 14.2 ± 8.0 vs. 8.7 ± 4.2, respectively, p < 0.01). TXI may be a useful observation modality in the endoscopic screening of the upper gastrointestinal tract.

Optical effect of spraying l-menthol on gastric intestinal metaplasia visualized by linked color imaging

OBJECTIVE

Linked color imaging (LCI) enables noninvasive detection of gastric intestinal metaplasia (GIM) as a lavender color sign (LCS), and there has been a recent report that l-menthol enhanced GIM with LCI. We measured color values of GIM and surrounding mucosa with white light imaging (WLI), LCI and LCI after spraying l-menthol (Mint-LCI) and investigated the effect of l-menthol on gastric mucosa.

METHODS

Endoscopic images of the antrum with WLI, LCI and Mint-LCI from 18 patients were prepared. Each of six regions of interest (three points of GIM and three points of surrounding mucosa) was selected for each modality, and CIE1976 (L*a*b*) color space was used to measure the color values. The primary endpoint was color differences (ΔE) between GIM and surrounding mucosa in each modality.

RESULTS

For surrounding mucosa, the mean a* value with Mint-LCI was significantly higher than the mean values with WLI and LCI (P < 0.01). The mean b* value of GIM with LCI was significantly lower than that of surrounding mucosa, and spraying l-menthol decreased the b* values of GIM with a change to a deeper lavender color (LCI: 10.0 ± 5.8, Mint-LCI: 3.7 ± 6.1, P < 0.01). However, there was no significant difference in mean ΔE values between LCI and Mint LCI (LCI: 21.1 ± 6.6, Mint-LCI: 22.7 ± 5.4, NS). After spraying l-menthol, the microstructure of GIM changed to translucent and microvessels were obscured.

CONCLUSIONS

As shown by LCI, spraying l-menthol optically enhances the color of GIM in the antrum.

Usefulness of linked color imaging in the early detection of superficial esophageal squamous cell carcinomas

BACKGROUND AND AIMS

Linked color imaging (LCI) improved the visibility of gastric cancer and colorectal flat lesions. This study aimed to investigate the usefulness of LCI in detecting superficial esophageal squamous cell carcinomas (SESCC).

METHODS

We enrolled 37 consecutive SESCC patients (46 SESCCs) diagnosed using LCI and blue laser imaging bright mode (BLI-BRT) and treated in Hiroshima University Hospital between April 2018 and November 2018. Eight professional endoscopists compared images obtained on non-magnifying BLI-BRT and LCI versus conventional white light imaging (WLI). Identification and boundary diagnosis of SESCC with LCI and BLI-BRT were compared with WLI. Changes in lesion visibility were clarified. Interobserver agreement was assessed. Clinicopathological features of lesion that influence visibility with LCI were assessed.

RESULTS

In LCI, 37% (17/46) of cases had improved visibility and 63% (29/46) had unchanged visibility (interobserver agreement = 0.74). Among cases with multiple lugol voiding lesions (LVLs), ΔE between the lesion and background mucosa was significantly higher in LCI than in WLI (20.8 ± 7.9 vs 9.2 ± 6.1, P < 0.05). No significant differences were found in tumor size, morphological type, color, depth, and smoking or drinking history. However, multiple LVLs were significantly higher among cases with improved versus unchanged visibility. On BLI-BRT, 39% (18/46) of cases had improved visibility and 61% (28/46) had unchanged visibility (interobserver agreement = 0.60).

CONCLUSION

Almost the same as BLI-BRT, LCI improves SESCC visibility compared with WLI. This is useful for cases with multiple LVLs. In cases without background coloration (BGC), LCI may make SESCC more visible than BLI-BRT.

Blue laser imaging and linked color imaging improve the color difference value and visibility of colorectal polyps in underwater conditions

BACKGROUND AND AIM

Underwater endoscopic mucosal resection (UEMR) has become widespread for treating colorectal polyps. However, which observational mode is best suited for determining polyp margins underwater remains unclear. To determine the best mode, we analyzed three imaging modes: white light imaging (WLI), blue laser imaging (BLI) and linked color imaging (LCI).

METHODS

Images of consecutive colorectal polyps previously examined by these three modes before UEMR were analyzed according to the degree of underwater turbidity (transparent or cloudy). Color differences between the polyps and their surroundings were calculated using the Commission Internationale d'Eclairage Lab color space in which 3-D color parameters were expressed. Eight evaluators, who were blinded to the histology, scored the visibility from one (undetectable) to four (easily detectable) in both underwater conditions. The color differences and visibility scores were compared.

RESULTS

Seventy-three polyps were evaluated. Sixty-one polyps (44 adenomatous, 17 serrated) were observed under transparent conditions, and 12 polyps (seven adenomatous, five serrated) were observed under cloudy conditions. Under transparent conditions, color differences for the BLI (8.5) and LCI (7.9) were significantly higher than that of WLI (5.7; P < 0.001). Visibility scores for BLI (3.6) and LCI (3.4) were also higher than that of WLI (3.1; P < 0.0001). Under cloudy conditions, visibility scores for LCI (2.9) and WLI (2.7) were significantly higher than that of BLI (2.2; P < 0.0001 and P = 0.04, respectively).

CONCLUSIONS

BLI and LCI were better observational modes in transparent water; however, BLI was unsuitable for cloudy conditions.

Benefits of linked color imaging for recognition of early differentiated-type gastric cancer: in comparison with indigo carmine contrast method and blue laser imaging

BACKGROUND AND AIM

Linked color imaging (LCI) is a novel endoscopy system, which enhances slight differences in mucosal color. However, whether LCI is more useful than other kinds of image-enhanced endoscopy (IEE) in recognizing early gastric cancer remains unclear. This study aimed to evaluate LCI efficacy compared with the indigo carmine contrast method (IC), and blue laser imaging-bright (BLI-brt) in early differentiated-type gastric cancer recognition.

METHODS

We retrospectively analyzed early differentiated-type gastric cancer, which were examined by all four imaging techniques (white light imaging, IC, LCI, BLI-brt) at Asahi University Hospital from June 2014 to November 2018. Both subjective evaluation (using ranking score: RS) and objective evaluation (using color difference score: CDS) were adopted to quantify early differentiated-type gastric cancer recognition.

RESULTS

During this period, 87 lesions were enrolled in this study. Both RS and CDS of LCI were significantly higher (p < 0.01) than those of IC and BLI-brt. Both RS and CDS of BLI-brt had no significant difference compared with those of IC. Subgroup analysis revealed that LCI was especially useful in post-Helicobacter pylori eradication patients and flat or depressed lesions compared with IC and BLI-brt.

CONCLUSIONS

LCI appears to be more beneficial for the recognition of early differentiated-type gastric cancer in endoscopic screenings than IC and BLI-brt from the middle to distant view.

Evaluation of the impact of linked color imaging for improving the visibility of colonic polyp

Linked color imaging (LCI) is a novel endoscopic system used to increase color contrast. As LCI does not decrease luminal brightness, it may improve the detection of colonic neoplasms. However, the extent to which LCI improves the visibility of colonic polyps has not yet been determined. Between December 2016 and May 2017, patients who received total colonoscopy were consecutively recruited into this retrospective, single-center study. For each polyp identified, images obtained from white light (WL) imaging, blue laser imaging (BLI), and LCI of the same lesion and its surrounding mucosa were evaluated. The color differences (ΔE) between each lesion and its surrounding mucosa in non-magnified images were computed quantitatively using the CIELAB color space, which defines color perception according to colorimetric values, and compared among WL, BLI, LCI, and chromoendoscopy. The ΔE between the vessel and non-vessel areas in magnified images was also assessed. Of the 64 patients who were incorporated into this study, non-magnified and magnified (×80) images from 113 and 95 polyps, respectively, were assessed. The ΔE was intensified by LCI and chromoendoscopy compared with WL and BLI. The ΔE of neoplastic lesions was also intensified by LCI. In magnified images, BLI and LCI significantly increased the ΔE between the vessel and non-vessel areas compared with WL. Luminal brightness, indicated by L*, was not impaired by LCI; however, was reduced by BLI compared with WL and LCI. These results suggest that LCI enhanced the detection of colonic neoplasms without impairing luminal brightness. We propose the routine use of LCI for colonic polyp detection and BLI for magnifying observations of colonic polyps detected by LCI.

White light-emitting contrast image capsule endoscopy for visualization of small intestine lesions: a pilot study

BACKGROUND AND STUDY AIMS

 Capsule endoscopy (CE) has become a routine means of diagnosing obscure gastrointestinal bleeding (OGIB) in the small intestine. Capsules using novel blue-enhanced white light-emitting diodes are expected to acquire clearer contrast images (CIs) of the small bowel vasculature. We conducted a pilot study to examine whether CIs facilitate visualization of small bowel erosions, ulcers, and areas of angioectasia compared with standard white light images (WLIs).

PATIENTS AND METHODS

 A total of 24 patients with OGIB were recruited in this study. The main outcome measure was visibility of lesions on CIs compared with WLIs. We also examined the color difference between lesions and normal mucosa (ΔE) with each imaging modality.

RESULTS

 Three experienced physicians retrospectively evaluated 138 images of small bowel lesions (107 erosions, or ulcers, and 31 areas of angioectasia) obtained from 24 CE examinations. The endoscopists judged that compared with WLIs, CIs afforded easier identification of erosions or ulcers in 29 of 107 cases (27.1 %), were non-inferior in 68 of 107 cases (63.6 %), and were inferior in 10 of 107 cases (9.3 %). Identification of angioectasia was judged to be easier with CIs in 15 of 31 cases (48.4 %), non-inferior in 13 of 31 cases (41.9 %), and inferior in 3 of 31 cases (9.7 %). ΔE was significantly higher for CIs than WLIs, especially for angioectasia, potentially explaining why lesions were easier to visualize.

CONCLUSIONS

 CIs obtained by CE appear to facilitate identification of small bowel erosions, ulcers, and areas of angioectasia compared with WLIs.

Evaluation of the Usefulness of Virtual Chromoendoscopy with Different Color Modes in the MiroCam® System for Characterization of Small Bowel Lesions

Background

Virtual chromoendoscopy (VC) in small bowel capsule endoscopy can improve the visualization and characterization of different small bowel lesions (SBLs). There are few studies of its usefulness in the Given® system, and there is no evidence yet of its utility in the MiroCam® system.

Aim

The aim of this study was to evaluate whether VC can improve the characterization of SBLs with the MiroCam® system.

Methods

Twenty-two patients were selected, in which 100 elementary lesions were identified, including erosions (n = 45), ulcers (n = 17), and angioectasias (n = 38). For each lesion identified, images were captured without chromoendoscopy (normal image [NI]) and with chromoendoscopy modes 1 (color mode [CM] 1), 2 (CM2), and 3 (CM3). A score from 1 to 4 was assigned to each image, in which a better evaluation of the characteristics and limits of the lesion was classified in ascending order, where 1 is the worst and 4 the best evaluation. The scores of the various modes were compared with Kendall's tau-c coefficient.

Results

The average scores attributed to the photographs in NI, CM1, CM2, and CM3 were 3.83, 2.89, 1.85, and 1.43, respectively (tau-c = -0.75, p < 0.001). Evaluating the elementary lesions independently, the average scores for modes NI, CM1, CM2, and CM3 were 3.83, 2.92, 1.86, and 1.38 (tau-c = -0.77, p < 0.001) for erosions, respectively; 3.87, 2.96, 1.76, and 1.40 (tau-c = -0.80, p < 0.001) for ulcers, respectively; and 3.81, 2.82, 1.87, and 1.50 (tau-c = -0.71, p < 0.001) for angioectasias, respectively.

Conclusions

VC using the CMs available in the MiroCam® system has not proven useful for a better assessment of any of the SBLs.

Objective Endoscopic Analysis with Linked Color Imaging regarding Gastric Mucosal Atrophy: A Pilot Study

Objectives

We aimed to determine whether linked color imaging (LCI), a new image-enhanced endoscopy that enhances subtle differences in mucosal colors, can distinguish the border of endoscopic mucosal atrophy.

Methods

This study included 30 patients with atrophic gastritis. In endoscopy, we continuously took images in the same composition with both LCI and white light imaging (WLI). In each image, the color values of atrophic and nonatrophic mucosae were quantified using the International Commission on Illumination 1976 (L^∗, a^∗, b^∗) color space. Color differences at the atrophic border, defined as Euclidean distances of color values between the atrophic and nonatrophic mucosae, were compared between WLI and LCI for the overall cohort and separately for patients with Helicobacter pylori infection status.

Results

We found that the color difference became significantly higher with LCI than with WLI in the overall samples of 90 points in 30 patients. LCI was 14.79 ± 6.68, and WLI was 11.06 ± 5.44 (P < 0.00001). LCI was also more effective in both of the Helicobacter pylori-infected group (P = 0.00003) and the Helicobacter pylori-eradicated group (P = 0.00002).

Conclusions

LCI allows clear endoscopic visualization of the atrophic border under various conditions of gastritis, regardless of Helicobacter pylori infection status.

Linked color imaging (LCI), a novel image-enhanced endoscopy technology, emphasizes the color of early gastric cancer

BACKGROUND AND STUDY AIMS

 Linked color imaging (LCI) and blue laser imaging (BLI) are novel image-enhanced endoscopy technologies with strong, unique color enhancement. We investigated the efficacy of LCI and BLI-bright compared to conventional white light imaging (WLI) by measuring the color difference between early gastric cancer lesions and the surrounding mucosa.

PATIENTS AND METHODS

 Images of early gastric cancer scheduled for endoscopic submucosal dissection were captured by LCI, BLI-bright, and WLI under the same conditions. Color values of the lesion and surrounding mucosa were defined as the average of the color value in each region of interest. Color differences between the lesion and surrounding mucosa (ΔE) were examined in each mode. The color value was assessed using the CIE L*a*b* color space (CIE: Commission Internationale d'Eclairage).

RESULTS

 We collected images of 43 lesions from 42 patients. Average ΔE values with LCI, BLI-bright, and WLI were 11.02, 5.04, and 5.99, respectively. The ΔE was significantly higher with LCI than with WLI ( P  < 0.001). Limited to cases of small ΔE with WLI, the ΔE was approximately 3 times higher with LCI than with WLI (7.18 vs. 2.25). The ΔE with LCI was larger when the surrounding mucosa had severe intestinal metaplasia ( P  = 0.04). The average color value of a lesion and the surrounding mucosa differed. This value did not have a sufficient cut-off point between the lesion and surrounding mucosa to distinguish them, even with LCI.

CONCLUSION

 LCI had a larger ΔE than WLI. It may allow easy recognition and early detection of gastric cancer, even for inexperienced endoscopists.

Small Bowel Capsule Endoscopy: Normal Findings and Normal Variants of the Small Bowel

Small bowel capsule endoscopy (SBCE) remains the gold standard for practice for the diagnosis of small bowel disorders. A rather challenging task, for those who start to use this diagnostic modality, is the recognition of the typical anatomic landmarks and the distinction of normal small bowel anatomy from abnormal findings. The reader of SBCE images may also often encounter unusual views of the normal anatomy as well as various artifacts that need to be distinguished from pathologic findings. Experience gained through standard endoscopy is invaluable to the interpretation of capsule examinations; however, formalized training and credentialing in reading competency are essential.

Detection of suspected small bowel bleeding: challenges and controversies

Detection of small bowel (SB) bleeding remains a challenge to gastroenterologists, with a dearth of standardized recommendations regarding evaluation and management. Areas covered: A recursive literature search was performed using PubMed, Cochrane and Medline databases for original and review articles on SB and obscure gastrointestinal bleeding (OGIB). Based upon the available literature, this review outlines the main challenges and controversies, and provides a practical and cost-effective approach towards SB bleeding. Expert commentary: SB bleeding is suspected in patients with persistent or recurrent bleeding after negative bidirectional endoscopy, and unexplained iron deficiency anemia. Selection of test(s) should be individualized based upon patient presentation and suspicion for type of underlying lesion. Endoscopic or radiologic evaluation and treatment is the mainstay in the majority of patients, while pharmacologic agents may have a role in patients with refractory bleeding, and those unable to undergo evaluation.

Efficacy of repeat review with flexible spectral imaging color enhancement in patients with no findings by capsule endoscopy

BACKGROUND/AIM

The efficacy of flexible spectral imaging color enhancement (FICE) ch. 1 (F1) for the detection of ulcerative lesions and angioectasias in the small intestine with capsule endoscopy (CE) has been reported. In the present study, we evaluated whether F1 could detect incremental findings in patients with no findings in a standard review mode.

PATIENTS AND METHODS

In total, 52 patients (age: 60.1 ± 15.3 years; 30 males) with obscure gastrointestinal bleeding (OGIB) who underwent CE and in whom no lesion was detected in the small intestine in the standard mode (first review) were enrolled. Two experienced endoscopists independently reviewed CE videos again by F1 (second review). The following findings were defined to be significant: Ulcers, erosions, aphthas, angioectasias, tumors, and bleeding. Incremental findings at the second review were checked at F1 and in standard mode by the two reviewers (third review). Finally, the findings were confirmed by the agreement of the two reviewers at the third review.

RESULTS

F1 detected five significant lesions in three patients with overt OGIB; three erosions, one aphtha, and one angioectasia. For nonsignificant lesions, F1 detected 12 red mucosas and 16 red spots. Moreover, 29 patients with 71 findings were considered false positives.

CONCLUSION

F1 detected incremental significant findings in a small percentage of patients with no findings in the standard review mode. In addition, F1 showed many false-positive findings. The incremental effect of a repeated review by F1 in patients with no findings in the first review is limited.

Progress in digestive endoscopy: Flexible Spectral Imaging Colour Enhancement (FICE)-technical review

Background. A substantial advance in digestive endoscopy that has been made during the last decade is represented by digital chromoendoscopy, which was developed as a quicker and sometimes better alternative to the gold standard of dye spraying. Fujifilm developed a virtual coloration technique called Flexible spectral Imaging Color Enhancement (FICE). FICE provides a better detection of lesions of "minimal" esophagitis, of dysplasia in Barrett's esophagus and of squamous cell esophageal cancer. The use of FICE resulted in an improvement in the visualization of the early gastric cancer, being less invasive, and time consuming than the classic dye methods. Current evidence does not support FICE for screening purposes in colon cancer but it definitely improves characterization of colonic lesions. Its use in inflammatory bowel disease is still controversial and in video capsule endoscopy is considered a substantial progress. Conclusions. The use of FICE endoscopy in routine clinical practice can increase the diagnostic yield and can provide a better characterization of lesions. Future studies to validate its use, the good choice of channels, and the "perfect indications" and to provide common definitions and classifications are necessary.