Flexible Spectral Imaging Color Enhancement Images Research Articles

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

Background and AimsWe prospectively aimed to determine the efficacy of flexible spectral imaging color enhancement (FICE) at second-generation colon capsule endoscopy (CCE) for colorectal polyps and tumors (CRTs). MethodsThis study included optical colonoscopy within four months after CCE. Two colonoscopists independently reviewed white light images (CCE-WL) and FICE images (CCE-FICE), respectively. Based on colonoscopic findings as the gold standard, the diagnostic accuracy for CRTs was compared between CCE-WL and CCE-FICE. ResultsOf 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 CRT was significantly higher than that of CCE-WL: overall CRTs (CCE-WL,79%; CCE-FICE,88%, P=0.0001), 6-9 mm CRTs (63%; 94%, P=0.0055), ≥6mm CRTs (78%; 93%, P=0.0159), respectively. The per-lesion sensitivity of CCE-FICE was significantly higher than that of CCE-WL for CRTs: overall (61%; 79%, P<0.0001), <6 mm (53%; 69%, P<0.0001) and 6-9 mm CRTs (65%; 93%, P=0.0007), slightly elevated CRTs (53%; 75 %, P<0.0001), tubular adenomas (61%; 79%, P<0.0001), and serrated polyps (57%; 74%, P=0.0022), respectively. Both modes detected all adenocarcinomas. There were no significant differences of the per-lesion sensitivity for ≥10 mm or protruding CRTs between CCE-WL and CCE-FICE (81%; 94%, P=0.1138, 77%; 86%, P=0.0614, respectively). Kappa coefficients for overall CRTs at CCE-WL and CCE-FICE were 0.66 and 0.64, respectively, which indicated substantial agreement. ConclusionsCCE-FICE improved the detection rates for all CRTs except adenocarcinomas, ≥10 mm and protruding polyps, when compared to CCE-WL (UMIN 000021125).

Evaluation of colon mucosa using screening colonoscopy and flexible spectral imaging color enhancement in patients with long lasting ulcerative colitis

AimTo determine which flexible spectral imaging color enhancement (FICE) channel best visualizes colon mucosa in ulcerative colitis (UC) and to compare FICE imaging with standard imaging.MethodsThe study enrolled patients with ulcerative colitis in remission who had inflammatory bowel disease for at least 8 years. All patients underwent screening colonoscopy. The entire colon, especially the suspicious areas in terms of dysplasia, were imaged with standard endoscopy and FICE. Random and target biopsies were obtained. Histopathological diagnosis was made and image patterns were evaluated. Seven endoscopists evaluated normal, colitis, and polyp images obtained with FICE.ResultsOne hundred and twenty-three colon segments were evaluated and 1831 images were obtained from 18 patients. A total of 1652 images were FICE and 179 were standard images. Separate FICE images were obtained for normal colon mucosa, polypoid lesions, and colitis areas. Normal colon mucosa was best visualized using the second, sixth, and ninth FICE channel; polyps using the third, seventh, and ninth channel; and colitis using the second, third, and ninth channel. When all images were analyzed, the second and ninth channel were significantly better than the other channels. A total of 584 biopsies were obtained, including 492 (84.2%) random biopsies and 92 (15.7%) target biopsies. Random biopsies detected no dysplasia, but target biopsies detected low-grade dysplasia in three diminutive polyps.ConclusionFICE was not significantly better at dysplasia screening than the standard procedure, but it effectively detected diminutive polyps and evaluated surface patterns without using magnification. FICE might contribute to the assessment of inflammation severity in patients with UC in clinical remission. However, more extensive studies are necessary to confirm these findings.

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

Background and study aims: The clinical utility of computed virtual chromoendoscopy with flexible spectral imaging color enhancement (FICE) in capsule endoscopy (CE) remains controversial. To clarify the clinical utility of FICE-enhanced CE in evaluating small bowel lesions, we quantitatively assessed white light (WL), FICE, and blue mode (BM) images and examined the sensitivity of these 3 imaging modes of small-bowel lesions from patients who underwent CE. Methods: The CIELAB color difference (∆E) and visual analogue scales (VAS) were measured in 261 CE images (3 different lesion categories) using WL and FICE set 1, 2, and 3, and BM images, respectively. Three endoscopists reviewed CE videos with WL, 3 FICE mode settings, and BM, and compared the sensitivity and detectability for small intestinal diseases from 50 patients who underwent CE. Results: In the assessment of visibility in the 152 vascular lesion images, the ∆E and VAS of FICE set 1, 2, and BM images were significantly higher than that of WL images. In 88 erosion/ulceration images, the ∆E and VAS of FICE set 1 and 2 images were significantly higher than that of WL images. In 21 tumor images, there were no significant differences in ∆E among these modalities. When analyzed on a per-patient basis, FICE settings 1 and 2 had the highest sensitivity (100 %) and specificity (97.3 – 100 %) for vascular lesions. As for erosive/ulcerative lesions, FICE setting 2 had the highest sensitivity (100 %) and specificity (97.2 %). For tumors or polyps, WL had the highest sensitivity (90.9 %) and specificity (87.1 %). In per-lesion analysis, FICE settings 1 and 2 showed significantly superior detection ability over WL for vascular lesions. In the detection of erosive/ulcerative lesions, FICE setting 2 was significantly superior to WL. In tumor images, there was no significant improvement with any of the settings relative to WL images. Conclusions: FICE is most useful for improving CE image quality and detection in cases of angioectasia and erosion/ulceration of the small intestine.

Usefulness of flexible spectral imaging color enhancement for the detection and diagnosis of small intestinal lesions found by capsule endoscopy

Objective. Capsule endoscopy (CE) is an established technique for the detection and diagnosis of obscure gastrointestinal bleeding (OGIB). Flexible spectral imaging color enhancement (FICE) is a software feature of RAPID 6.5. This study assessed the value of FICE for accurate identification of red lesions during CE. Methods. We randomly selected 10 patients who underwent CE for OGIB at Juntendo University. The CE images were read by five endoscopists. Small bowel videos, which were recorded by regular CE devices (PillCam SB2, Given Imaging), were evaluated on RAPID 6.5. We standardized the reading condition to a dual view, at a speed of 20 frames/s in manual mode. This interpreted FICE-CE images obtained at settings 1–3. Both conventional and FICE images were read at random. We defined a conventional image as standard and investigated the potential of FICE in detecting small intestinal lesions by the Steel–Dwass test. Results. We considered that conventional images represented baseline (100). On this basis, detection rates for FICE images were as follows: FICE1 = 266.4 ± 33.1 (p < 0.0001); FICE2 = 255.4 ± 25.6 (p < 0.0001); and FICE3 = 117.0 ± 12.3 (p = 0.9447). Detection rates using FICE1 and FICE2 images were significantly higher than conventional CE images. FICE1 and FICE2 were more useful in detecting erosions than conventional CE (p < 0.0001) and FICE3 (p < 0.0001). Conclusions. FICE-CE has a high level of visibility by transparentizing bile or enhancing the color difference associated with reddish mucosa. We found that FICE-CE images were useful in the diagnosing of small intestinal lesions.

Recognition of Endoscopic Diagnosis in Differentiated-Type Early Gastric Cancer by Flexible Spectral Imaging Color Enhancement with Indigo Carmine

Background/Aims: To evaluate the usefulness of flexible spectral imaging color enhancement with indigo carmine (I-FICE) in early gastric cancer (EGC) demarcation. Methods: The study participants were 29 patients with differentiated-type EGC. The endoscope was fixed and images of the same area of EGC demarcations in each lesion were obtained using four different methods (WLE, flexible spectral imaging color enhancement (FICE), CE, and I-FICE). FICE mode at R 550 nm (Gain: 2), G 500 nm (Gain: 4), and B 470 nm (Gain: 4) was used. Four endoscopists ranked the images obtained by each method on the basis of the ease of recognition of demarcation using a 4-point system. We calculated the standard deviation of pixel values based on L*, a*, and b* color spaces in the demarcation region (Lab-SD score). Results: The median ranking score for I-FICE images was significantly higher than that obtained from the other methods. Further, the average Lab-SD score was significantly higher for I-FICE images than for images obtained by the other methods. There was a good correlation between the ranking score and Lab-SD score. Conclusion: EGC demarcations were most easily recognized both subjectively and objectively using I-FICE image, followed by CE, FICE and WLE images.

Virtual chromoendoscopy can be a useful software tool in capsule endoscopy

capsule endoscopy (CE) has revolutionized the study of small bowel. One major drawback of this technique is that we cannot interfere with image acquisition process. Therefore, the development of new software tools that could modify the images and increase both detection and diagnosis of small-bowel lesions would be very useful. The Flexible Spectral Imaging Color Enhancement (FICE) that allows for virtual chromoendoscopy is one of these software tools. to evaluate the reproducibility and diagnostic accuracy of the FICE system in CE. this prospective study involved 20 patients. First, four physicians interpreted 150 static FICE images and the overall agreement between them was determined using the Fleiss Kappa Test. Second, two experienced gastroenterologists, blinded to each other results, analyzed the complete 20 video streams. One interpreted conventional capsule videos and the other, the CE-FICE videos at setting 2. All findings were reported, regardless of their clinical value. Non-concordant findings between both interpretations were analyzed by a consensus panel of four gastroenterologists who reached a final result (positive or negative finding). in the first arm of the study the overall concordance between the four gastroenterologists was substantial (0.650). In the second arm, the conventional mode identified 75 findings and the CE-FICE mode 95. The CE-FICE mode did not miss any lesions identified by the conventional mode and allowed the identification of a higher number of angiodysplasias (35 vs 32), and erosions (41 vs. 24). there is reproducibility for the interpretation of CE-FICE images between different observers experienced in conventional CE. The use of virtual chromoendoscopy in CE seems to increase its diagnostic accuracy by highlighting small bowel erosions and angiodysplasias that weren´t identified by the conventional mode.

Sa1592 Improved Visualization of Small Bowel Lesions by Capsule Endoscopy Using Flexible Spectral Imaging Color Enhancement (FICE) System

Improved Visualization of Small Bowel Lesions by Capsule Endoscopy Using Flexible Spectral Imaging Color Enhancement (FICE) System Yasushi Sato*, Masahiro Hirakawa, Hiroyuki Ohnuma, Kohichi Takada, Tsutomu Sato, Koji Miyanishi, Rishu Takimoto, Masayoshi Kobune, Junji Kato Sapporo Medical University, School of Medicine, Sapporo, Japan Background and Aim: Computed virtual chromoendoscopy with flexible spectral imaging color enhancement (FICE) offers improved detection and characterization of the gastrointestinal tract lesions and are applied widely in clinical practice at gastroscopy and colonoscopy; however, its clinical usefulness in capsule endoscopy remain to be firmly established. The aim of this study was to evaluate the clinical usefulness of the FICE-enhanced capsule endoscopy system comparing with conventional, white light images. Methods: Three experienced endoscopists compared FICE images with corresponding conventional images of 232 lesions obtained from 151 patients who underwent video CE at our hospital between January 2009 and November 2011.The lesions were classified as angioectasia, erosion/ulceration, or tumor, and these images were viewed using white light and 3 different sets of FICE images (ie, setting 1: red 595 nm, green 540 nm, blue 535 nm; setting 2: red 420 nm, green 520 nm, blue 530 nm; setting 3: red 595 nm, green 570 nm, blue 415 nm). Endoscopists rated the visibility of the lesions on FICE images as follows: 2 (marked improvement), 1 (modest improvement), 0 (remain the same as conventional images), 1 (slight decrease), and 2 (marked decrease). Scores for each lesion were totaled per FICE setting and evaluated. Inter-observer agreement was also examined. The time taken to interpret the capsule videos was also determined. Results: With FICE setting 1, the mean visibility score was 4.7 0.4 for angioectasia images, 2.7 0.4 for erosion/ulceration images, and 0.8 0.2 for tumor images. With setting 2, the mean visibility scores were 4.3 0.4, 3.0 0.9, and 0.4 0.4, respectively. With setting 3, the mean visibility scores were 0.8 0.2, 0.3 0.4, and 2.8 0.4, respectively. The inter-observer agreement was good (mean weighted kappa 0.79). Interpretation times were 36 6.9 min, 33 5.4 min, 35 2.8, and 36 5.2 with conventional CE, CE-FICE setting 1, setting 2, and setting 3, respectively, and there was no significant difference among the 4 groups (P 0.05). Conclusions: FICE imaging adds valuable information to conventional CE imaging and enables better diagnostic utility for small-bowel lesions of angioectasia or erosion/ulceration, especially with the use of FICE setting 1 or 2.

Diagnosis of depressed-type early gastric cancer using small-caliber endoscopy with flexible spectral imaging color enhancement

Small-caliber endoscopy has lower resolution than normal-caliber endoscopy, limiting its use in routine outpatient practice. Flexible spectral imaging color enhancement (FICE) strengthens the color contrast of depressed-type early gastric cancer without magnification. The aim of the present study was to evaluate the detection of depressed-type early gastric cancer using small-caliber endoscopy with the FICE system. Eighty-two patients diagnosed with depressed-type early gastric cancer by standard endoscopy and biopsy were evaluated by small-caliber endoscopy. FICE images and conventional images were compared. Color differences in all 82 lesions were measured between malignant lesions and the surrounding mucosa using the Commission Internationale de L'Eclairage (CIE) 1976 color space. Most cancers were readily detected as reddish lesions on FICE images. Lines of demarcation between the malignant lesion and the surrounding mucosa were easily identified with FICE images, as such cancers could be clearly distinguished from the surrounding atrophic mucosa. Greater median color differences between malignant lesions and the surrounding mucosa were present in FICE images compared with conventional images, resulting in images with better contrast (27.2 vs 18.7, P<0.0001). Small-caliber endoscopy with the FICE system provides better color contrast of depressed-type early gastric cancers than conventional small-caliber endoscopy, and the FICE system may facilitate the diagnosis of this type of cancer as a new endoscopic modality.

The endoscopic diagnosis of nonerosive reflux disease using flexible spectral imaging color enhancement image: a feasibility trial

Nonerosive reflux disease (NERD) is classified into grade M (minimal change, endoscopically; erythema without sharp demarcation, whitish turbidity, and/or invisibility of vessels due to these findings) and grade N (normal) in the modified Los Angeles classification system in Japan. However, the classification of grades M and N NERD is not included in the original Los Angeles system because interobserver agreement for the conventional endoscopic diagnosis of grades M or N NERD is poor. Flexible spectral imaging color enhancement (FICE) is a virtual chromoendoscopy technique that enhances mucosal and vascular visibility. The aim of this study is to evaluate whether the endoscopic diagnosis of grades M or N NERD using FICE images is feasible. Between April 2006 and May 2008, 26 NERD patients and 31 controls were enrolled in the present study. First, an experienced endoscopist assessed the color pattern of minimal change in FICE images using conventional endoscopic images and FICE images side-by-side and comparing the proportion of minimal change between the two groups. Second, three blinded endoscopists assessed the presence or absence of minimal change in both groups using conventional endoscopic images and FICE images separately. Intraobserver variability was compared using McNemar's test, and interobserver agreement was described using the kappa value. Minimal changes, such as erythema and whitish turbidity, which were detected using conventional endoscopic images, showed up as navy blue and pink-white, respectively, in color using FICE images in the present FICE mode. The NERD group had a higher proportion of minimal change, compared with the control group (77% and 48%, respectively) (P= 0.033). In all three readers, the detection rates of minimal change using FICE images were greater than those using conventional endoscopic images (P= 0.025, <0.0001, and 0.034 for readers A, B, and C, respectively). The kappa values for all pairs of three readers using FICE images were between 0.683 and 0.812, while those using conventional endoscopic images were between 0.364 and 0.624. Thus, the endoscopic diagnosis of grades M or N NERD using FICE images is feasible and may improve interobserver agreement.

Improved visibility of lesions of the small intestine via capsule endoscopy with computed virtual chromoendoscopy

We can now enhance video capsule endoscopy (CE) images in real time by means of a flexible spectral imaging color enhancement (FICE) digital processing system. Reports on the clinical usefulness of this system are few. To clarify whether visualization of lesions of the small intestine is improved by FICE image analysis. A retrospective study. Academic medical center. Five physicians compared FICE images with corresponding conventional images of 145 lesions obtained from 122 patients who underwent video CE at our hospital. The lesions were classified as angioectasia (n=23), erosion/ulceration (n=45), or tumor (n=75), and 3 different sets of FICE images were viewed (ie, at 3 different wavelength settings). Physicians rated the visibility of the lesions on FICE images as follows: +2 (improved visibility), +1 (somewhat improved visibility), 0 (visibility equivalent to that of conventional video CE visibility), -1 (somewhat decreased visibility), and -2 (decreased visibility). Scores for each lesion were totaled (per FICE setting) and evaluated. Intraobserver agreement was also examined. With FICE setting 1 (red 595 nm, green 540 nm, blue 535 nm), improvement was achieved for 87% (20/23) of angioectasia images, 53.3% (26/47) of erosion/ulceration images, and 25.3% (19/75) of tumor images. With setting 2 (red 420 nm, green, 520 nm, blue 530 nm), improvement was achieved for 87% (20/23), 25.5% (12/47), and 20.0% (15/75), respectively. With setting 3, only equivalence was achieved. Intraobserver agreement was good to satisfactory at 5.4 or higher. Single-center study. CE-FICE improves visibility of small-bowel angioectasia, erosion/ulceration, and tumor.

Diagnosis of gastric antral vascular ectasia by transnasal flexible spectral imaging color enhancement.

The endoscopic appearance of gastric antral vascular ectasia (GAVE) can be easily misinterpreted as inflammatory changes of gastric mucosa. We report on a case of GAVE that had been missed by conventional transnasal endoscopy but was diagnosed by flexible spectral imaging color enhancement (FICE) with a transnasal endoscope. A 45-year-old woman with severe anemia presented with a 1-month history of increasing fatigue. She was previously diagnosed as having acute antral gastritis by conventional transnasal endoscopy (EG 530N2) because of the presence of reddish mucosal changes on the entire antral rugal fold. However, the FICE images produced using a combination of new processor system (VP4450) and new small-caliber endoscope (EG 530NW), did not show reddish mucosal changes on the entire rugal fold, but gave a clear image of dilated vessels associated with GAVE distinct from the surrounding normal mucosa on the same fold. These findings are useful to differentiate GAVE from ordinary gastritis. The lesions of GAVE were managed with a combination of focal pulse and spray-painting techniques to obliterate the bulk of the disease in two sessions of argon plasma coagulation therapy. Three months later, the patient recovered from iron deficiency anemia with an oral medication of iron tablets.

Objective evaluation of visibility in virtual chromoendoscopy for esophageal squamous carcinoma using a color difference formula

Computed virtual chromoendoscopy with flexible spectral imaging color enhancement (FICE) is a new dyeless imaging technique that enhances mucosal and vascular patterns. However, a method for selecting a suitable wavelength for a particular condition has not been established. The aim of this study is to evaluate the color difference method for quality assessment of FICE images of the intrapapillary capillary loop in magnifying endoscopy for esophageal squamous cell carcinoma. The color difference between 60 microvessels and background mucosa observed using the magnifying endoscope was 8.31±2.84 SD under white light and 12.26±3.14 (p=0.0031), 11.70±4.49 (p=0.0106), and 17.49±5.40 (p<0.0001) in FICE modes A, B, and C, respectively. The visibility scores for microvessels observed by medical students were 6.00±1.12 points under white light and 11.1±2.25 (p<0.0001), 8.65±2.06 (p=0.0001), and 12.55±2.56 (p<0.0001) in FICE modes A, B, and C, respectively. Furthermore, the measurement of color difference was correlated with the visibility score assigned by medical students (Pearson's correlation coefficient=0.583, p<0.0001) In conclusion, the color difference method corresponds to human vision and is an appropriate method for evaluation of endoscopic images.

Diagnosis of endoscopic Barrett’s esophagus by transnasal flexible spectral imaging color enhancement

The diagnosis of endoscopic Barrett's esophagus (BE) has been under discussion for the past decade because palisade vessels may be obscured by inflammation or the location of upper end of gastric fold may be diversely changed. The flexible spectral imaging color enhancement (FICE) system can reconstruct improved spectral images decomposed from ordinary endoscopic images with free selection of three wavelengths, and can provide non-magnified images with high light intensity. To evaluate whether the transnasal FICE system enables easier diagnosis of endoscopic BE, 72 patients with endoscopic BE were observed prospectively with a transnasal endoscope using both conventional images and FICE images. The visualization of palisade vessels and the identification of the demarcation between endoscopic BE mucosa and gastric mucosa were compared between FICE images and conventional endoscopic images, and the CIELAB color differences were calculated among palisade vessels, background BE mucosa and gastric folds. Palisade vessels could be more clearly visualized in BE mucosa with transnasal FICE than with conventional endoscopy. Demarcation between whitish BE mucosa and the upper end of the brownish gastric mucosa could be clearly identified using transnasal FICE images. Greater color differences existed with FICE images between palisade vessels and background BE mucosa as well as between BE mucosa and gastric folds than with conventional images, leading to better contrasting images. The transnasal FICE system enables clear visualization of palisade vessels and provides better contrasting images of the demarcation between the BE mucosa and the gastric mucosa, and thus contributes to easier diagnosis of endoscopic BE.

Objective Evaluation of the Visibility On FICE Images Using a Color Difference Formula

Background and Purpose: Flexible spectral imaging color enhancement (FICE) is a new image enhancement system based on ‘spectral estimation technology’ that has been developed at Chiba University. Mode setting corresponding to organs, observation methods, and purpose is possible because wavelengths to be extracted can be selected. To select a setting from an infinite number of combinations of wavelength, an index to objectively evaluate the ‘visibility’ of acquired images is necessary. In this study, we investigated the mode appropriate for observation by quantifying the contrast between ‘background mucosa’ and ‘lesions’ of early stage gastric cancer on endoscopy. [Subjects] The subjects were 20 patients with early stage gastric cancer who underwent endoscopy using normal white light, FICE, and indigo carmine dye. Methods: (1) Using image analysis software (Photoshop 6.0, Adobe), the colors of the pixels in the background mucosal regions sandwiching the boundary of the lesion and those of the lesion were described with the CIE Lab colorimetric system. The color sense of the CIE Lab colorimetric system is closer to that of humans, compared to the RGB colorimetric system generally used for the expression of colors. Using this colorimetric system, the contrast between two points can be quantified using the color difference formula = CIEΔ Ea∗b∗. The color difference increases as this value increases, and is interpreted as an endoscopically ‘clear boundary’. The color was measured at 3 points per image, and images obtained under conventional white light, 6 types of FICE image, and dye endoscopy image with indigo carmine were compared. (2) To investigate the validity of the test using the color difference formula, the images under general white light and FICE images used in (1) were presented to 10 medical school students with no experience of endoscopy, and the students lined up the images in the order of ‘visibility’. [Results] On endoscopic observation of early stage gastric cancer, lesions were more clearly imaged by FICE imaging under red: 550 nm, green: 500 nm, and blue: 470 nm (18.3 ± 7.3) and that under red: 525 nm, green: 495 nm, and blue: 495 nm (20.7 ± 9.5, p<0.05), compared to images obtained under conventional white light (14.6 ± 11.5). Similar findings were obtained from the student questionnaire. [Discussion] When ‘visibility’ on FICE imaging was quantified using the imaging engineering technique, the values correlated with ‘visibility’ indicated by the observers. Using this technique, optimum wavelengths for FICE imaging can be readily established for each case.

Evaluation and validation of computed virtual chromoendoscopy in early gastric cancer

The Flexible spectral Imaging Color Enhancement (FICE) system estimates the spectrum reflectance from a white-light endoscopic image and reconstitutes a color image from the wavelength, including useful information about the GI tract. The aim of this study was to investigate the usefulness of FICE with a specific wavelength in the assessment of early gastric cancers (EGCs), and the relationship between the FICE visualization and blood vessels. A retrospective study. Department of Endoscopy, Hiroshima University, Hiroshima, Japan. The study subjects consisted of 100 patients with EGCs (78 differentiated, 22 undifferentiated) who underwent an endoscopic or surgical resection. We analyzed the wavelengths to generate the maximum difference of the spectral reflectance between the normal gastric mucosa and the EGCs. We observed the same visual field first with white-light endoscopy and then with the FICE system. Then, we scored the demarcation of color between the cancer and the normal mucosa of white-light endoscopic observation and FICE observation, each without magnification. We examined the relationship between the score of the FICE image and the section of the vascular space. The wavelength that generated the maximum difference in the tissue was 530 nm. The score of the FICE observation improved in 46 cases (46%), was unchanged in 54 cases (54%), and decreased in no cases (0%). There was a correlation between the score of the FICE images and the section of the vascular spaces. The FICE observation demonstrated that setting the wavelength at 530 nm resulted in an improvement in the visualization of the EGCs. It is thought that the FICE system is noninvasive and may more easily detect EGC without dye during both routine and detailed examinations.