Autofluorescence Imaging System Research Articles

Multimodal fluorescence imaging and spectroscopic techniques for oral cancer screening: a real-time approach

The survival rate of oral squamous cell carcinoma (OSCC) patients is very poor, but it can be improved using highly sensitive, specific, and accurate techniques. Autofluorescence and fluorescence techniques are very sensitive and helpful in cancer screening; being directly linked with the molecular levels of human tissue, they can be used as a quantitative tool for cancer detection. Here, we report the development of multi-modal autofluorescence and fluorescence imaging and spectroscopic (MAF-IS) smartphone-based systems for fast and real-time oral cancer screening. MAF-IS system is indigenously developed and offers the advantages of being a low-cost, handy, non-contact, non-invasive, and easily operable device that can be employed in hospitals, including low-resource settings. In this study, we report the results of 43 individuals with 28 OSCC and 15 oral potentially malignant disorders (OPMDs), i.e., epithelial dysplasia and oral submucous fibrosis, using the developed devices. We observed a red shift in fluorescence emission spectra in vivo. We found red-shift of 7.72 ± 6 nm, 3 ± 4.36 nm, and 1.33 ± 0.47 nm in the case of OSCC, epithelial dysplasia, and oral submucous fibrosis, respectively, compared to normal. The results were compared with histopathology and found to be consistent. Further, the MAF-IS system provides results in real-time with higher accuracy and sensitivity compared to devices using a single modality. Our system can achieve an accuracy of 97% with sensitivity and specificity of 100% and 94.7%, respectively, even with a smaller number of patients (28 patients of OSCC). The proposed MAF-IS device has great potential for fast screening and diagnosis of oral cancer in the future.

The magic mirror: a novel intraoperative monitoring method for parathyroid glands.

The accurate detection of parathyroid glands (PGs) during surgery is of great significance in thyroidectomy and parathyroidectomy, which protects the function of normal PGs to prevent postoperative hypoparathyroidism and the thorough removal of parathyroid lesions. Existing conventional imaging techniques have certain limitations in the real-time exploration of PGs. In recent years, a new, real-time, and non-invasive imaging system known as the near-infrared autofluorescence (NIRAF) imaging system has been developed to detect PGs. Several studies have confirmed that this system has a high parathyroid recognition rate and can reduce the occurrence of transient hypoparathyroidism after surgery. The NIRAF imaging system, like a magic mirror, can monitor the PGs during surgery in real time, thus providing great support for surgeries. In addition, the NIRAF imaging system can evaluate the blood supply of PGs by utilizing indocyanine green (ICG) to guide surgical strategies. The NIRAF imaging system and ICG complement each other to protect normal parathyroid function and reduce postoperative complications. This article reviews the effectiveness of the NIRAF imaging system in thyroidectomies and parathyroidectomies and briefly discusses some existing problems and prospects for the future.

Handheld Autofluorescence Imaging System for Intraoperative Parathyroid Detection.

Hypoparathyroidism and hypocalcemia are common complications after thyroid surgery. Parathyroids may be incidentally damaged or removed because they are difficult to distinguish from surrounding tissue. Intraoperative optical technologies such as near infrared autofluorescence (NIRAF) are becoming increasingly popular to help identify parathyroids during thyroid surgery. The objective of this video is to introduce a developing NIRAF device called hANDY-i and compare the device with existing Food and Drug Administration approved technology. hANDY-i is developed by Optosurgical, LLC. The device consists of a coaxial 785 nm laser excitation module and coregistred red-green-blue and near-infrared cameras. Operation of the device and output from preliminary intraoperative use are shown. hANDY-i performs well, producing intuitive side-by-side NIRAF and RGB images of the operating field. The device demonstrates high contrast between suspected parathyroid glands and surrounding tissue. Operating theater, overhead lamps, and surgical headlights can all be used with the device. The device is also shown to be effective in both in vivo and ex vivo applications. The prototype described advance NIRAF technology by reducing light sensitivity and improving output representation. In doing so, hANDY-i makes NIRAF more accessible and less obstructive to the surgical workflow. This study was supported by the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health under Award Number R43EB030874. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.Yoseph Kim is an employee of Optosurgical LLC. Jaepyeong Cha has ownership stake in Optosurgical LLC. For all other authors, no competing financial interests exist.Runtime of video: 7 mins 14 secs.

Triple-clad W-type fiber mitigates multipath artifacts in multimodal optical coherence tomography.

Multimodal endoscopic optical coherence tomography (OCT) can be implemented with double-clad fiber by using the presumed single-mode core for OCT and the higher numerical aperture cladding for a secondary modality. However, the quality of OCT in double-clad fiber (DCF) based systems is compromised by the introduction of multipath artifacts that are nt present in single-mode fiber OCT systems. Herein, the mechanisms for multipath artifacts in DCF are linked to its modal contents using a commercial software package and experimental measurement. A triple-clad W-type fiber is proposed as a method for achieving multimodal imaging with single-mode quality OCT in an endoscopic system. Simulations of the modal contents of a W-type fiber are compared to DCF and single-mode fiber. Finally, a W-Type fiber rotary catheter is used in a DCF-based endoscopic OCT and autofluorescence imaging (AFI) system to demonstrate multipath artifact free OCT and AFI of a human fingertip.

Diagnosis of advanced gastric cancer using image enhancement and autofluorescence imaging systems.

The indication of laparoscopic gastrectomy for advanced cases such as serosal invasion or peritoneal dissemination is still controversial. We report the clinical experiences of laparoscopic diagnosis with image enhancement and autofluorescence (AF) systems for laparoscopic gastric cancer surgery. The image enhancement system was introduced to 164 patients who underwent laparoscopic gastric cancer surgery as the AF group. The control group was defined as 165 cases who underwent bright light observation without the image enhancement system. The operative findings were recorded during surgery. All image findings were retrospectively compared with the pathological findings. Furthermore, the relationship between the image and pathological findings for peritoneal dissemination and subserosal invasion was evaluated. This study included 329 patients, divided into the control group of 165 patients (50.2%) and the AF group of 164 patients (49.8%). There was no statistically significant difference in patient background between the two groups. In seven cases of peritoneal dissemination, AF was positive, and macroscopic abnormal vascularization was detected. The sensitivity, specificity, and positive and negative predictive values were 100%, 99.4%, 87.5%, and 100%, respectively. In 29 cases of serosal invasion, AF was positive, and macroscopic abnormal vascularization was detected. In the detection accuracy of subserosal invasion, the sensitivity, specificity, and positive and negative predictive values were 75.7%, 97.6%, 90.3%, and 93.2%, respectively. The image enhancement with the AF system is useful for the laparoscopic intraoperative diagnosis of serosal invasion and peritoneal dissemination for advanced gastric cancer.

Detection of breast cancer precursor lesions by autofluorescence ductoscopy

PurposeAutofluorescence is an image enhancement technique used for the detection of cancer precursor lesions in pulmonary and gastrointestinal endoscopy. This study evaluated the feasibility of addition of autofluorescence to ductoscopy for the detection of intraductal breast cancer precursor lesions.MethodsAn autofluorescence imaging system, producing real-time computed images combining fluorescence intensities, was coupled to a conventional white light ductoscopy system. Prior to surgery, ductoscopy with white light and autofluorescence was evaluated under general anaesthesia in women scheduled for therapeutic or prophylactic mastectomy. Endoscopic findings in both modes were compared, marked and correlated with histology of the surgical specimen.ResultsFour breast cancer patients and five high-risk women, with a median age of 47 years (range 23–62) were included. In autofluorescence mode, two intraductal lesions were seen in two breast cancer patients, which had an increase in the red-to-green fluorescence intensity compared with the surrounding tissue. One lesion had initially been missed by white light ductoscopy but was clearly visible in subsequent autofluorescence mode. One endoscopic finding was classified as suspicious by white light, but was negative in autofluorescence mode and showed normal histology.ConclusionsThis study demonstrates for the first time the in vivo feasibility of autofluorescence ductoscopy to detect pathologically confirmed breast cancer precursor lesions in both breast cancer patients and high-risk women that were occult under white light.

An Examination of the Usefulness of Photodynamic Diagnoses Using 5-Aminolevulinic Acid and an Autofluorescence Imaging System of Malignant Pleural Diseases

An Examination of the Usefulness of Photodynamic Diagnoses Using 5-Aminolevulinic Acid and an Autofluorescence Imaging System of Malignant Pleural Diseases

Optimization of Demosaicing Algorithm for Autofluorescence Imaging System

Autofluorescence imaging (AFI) systems are widely used in the detection of precancerous lesions. Fluorescence images of precancerous tissue are usually red (R) or blue (B), so this kind of system has high requirement for colour recovery, especially in R and B channels. Besides, AFI system requires bulk data transmission with no time delay. Existing colour recovery algorithms focus more on green (G) channel, overlooking R and B channels. Although the state-of-art demosaicing algorithms can perform well in colour recovery, they often have high computational cost and high hardware requirements. We propose an efficient interpolation algorithm with low complexity to solve the problem. When calculating R and B channel values, we innovatively propose the diagonal direction to select the interpolation direction, and apply colour difference law to make full use of the correlation between colour channels. The experimental results show that the peak signal-to-noise ratios (PSNRs) of G, R and B channels reach 37.54, 37.40 and 38.22 dB, respectively, which shows good performance in recovery of R and B channels. In conclusion, the algorithm proposed in this paper can be used as an alternative to the existing demosaicing algorithms for AFI system.

Real-time computer-aided diagnosis of diminutive rectosigmoid polyps using an auto-fluorescence imaging system and novel color intensity analysis software

Objectives: An endoscopic technique that provides ≥90% negative predictive value (NPV) for differentiating neoplastic polyps is needed for the management of diminutive (≤5 mm) rectosigmoid polyps. This study aimed to assess whether a newly developed software can achieve ≥90% NPV for differentiating rectosigmoid diminutive polyps based on the green-to-red (G/R) ratio, obtained by dividing the green color tone intensity by the red color tone intensity on autofluorescence imaging (AFI).Methods: From December 2017 to May 2018, consecutive patients with known polyps who were scheduled for endoscopic treatment at our institution were prospectively recruited. All colorectal diminutive polyps were differentiated by computer-aided diagnosis using autofluorescence imaging (CAD-AFI) using a novel software-based automatic color intensity analysis; subsequent diagnosis was made by endoscopists based on trimodal imaging endoscopy (TME), which combines AFI, white-light imaging (WLI) and magnifying narrow-band imaging (M-NBI) findings. Thereafter, all polyps were removed endoscopically, and the histopathological diagnosis was evaluated.Results: Ninety-five patients with 258 diminutive rectosigmoid polyps and 171 diminutive non-rectosigmoid polyps were enrolled. Regarding diminutive rectosigmoid polyps, the NPV for differentiating neoplastic polyps was 93.4% (184/197) [95% confidence interval (CI), 89.0%–96.4%] with CAD-AFI and 94.9% (185/195) (95% CI, 90.8%–97.5%) with TME. The accuracy, sensitivity, specificity, and positive predictive value for differentiating diminutive rectosigmoid neoplastic polyps by CAD-AFI were 91.5%, 80.0%, 95.3% and 85.2%, respectively.Conclusions: Real-time CAD-AFI was effective for differentiating diminutive rectosigmoid polyps. This objective technology, which does not require extensive training or endoscopic expertise, can contribute to the effective management of diminutive rectosigmoid polyps.

Intraoperative Parathyroid Autofluorescence Detection in Patients with Primary Hyperparathyroidism.

Intrinsic near-infrared (NIR) autofluorescence of the parathyroid gland may improve intraoperative gland identification without the need for contrast agent injection. Compared with patients undergoing surgery for thyroid disease, identification of pathologic parathyroid tissue in patients with hyperparathyroidism is essential. This study analyzed the utility of a novel real-time autofluorescence imaging system in patients with primary hyperparathyroidism enrolled in a prospective feasibility clinical trial. Data on patients undergoing surgery for primary hyperparathyroidism by two experienced endocrine surgeons were prospectively collected. Intraoperative imaging was performed with a handheld NIR device, and images were captured for analysis. The collected data included the surgeon's confidence in parathyroid identification, both with ambient light and use of NIR imaging, as well as how the imaging affected the surgical procedure. Images were quantified by Image J software, with autofluorescence reported as mean values ± SD. From 2017 to 2018, 59 consecutive patients with a diagnosis of primary hyperparathyroidism underwent resection of 69 parathyroid glands. Use of NIR imaging increased the intraoperative confidence of parathyroid identification (on a scale of 0-5) from an average of 4.1 to an average of 4.4 (+0.3, p = 0.003), all of which were confirmed pathologically. The addition of autofluorescence helped to identify the parathyroid gland in 12 patients (20%), and to rule out other soft tissue as not parathyroid in an additional 9 patients (15%). The mean autofluorescence for the parathyroid in situ (75.9 ± 21.3) was significantly greater than that for the thyroid (61.1 ± 17.4) or soft tissue (53.3 ± 19.2) (p < 0.001 for both). The mean absolute difference in parathyroid versus background thyroid autofluorescence was +15.2 (range, 2.4-53.1). This is the first prospective trial to examine the utility of parathyroid autofluorescence for identifying glands exclusively in patients with parathyroid disease. Intraoperative identification and localization of parathyroid glands by real-time, NIR imaging using their intrinsic autofluorescence is feasible and may provide a useful adjunct during parathyroid surgery.

Abstract 16616: Assessment of Lipid Rich Plaque Containing Necrotic Core Using a Multi-Modality Near-Infrared Autofluorescence and Optical Coherence Tomography Imaging System

Introduction: Optical coherence tomography (OCT) is thought to be capable of identifying lipid-rich plaque (LRP). However, several histopathological correlative studies have shown that LRP assessment by OCT alone may be indecisive for identifying advanced plaque containing a necrotic core. This study aims to investigate the feasibility of multi-modality OCT-near-infrared autofluorescence (NIRAF) imaging to identify advanced necrotic-core LRP. Methods: We constructed a new fully integrated multi-modality OCT-NIRAF imaging system and catheter that allows simultaneous and co-registered acquisition of OCT and NIRAF data. NIRAF excitation was 635nm and emission was collected between 690-750nm. OCT-NIRAF pullback imaging was performed with excised human cadaver coronary arteries during saline perfusion. Subsequently, H&amp;E sections were obtained and co-registered (longitudinally and azimuthally) with corresponding OCT-NIRAF images, using the known pullback distances, and anatomic landmarks and features such as calcium nodules seen in the OCT and histopathology images. In addition, a bench top confocal microscope was used to obtain images of NIRAF on corresponding unstained, formalin-fixed, paraffin-embedded slides. Results: A total of 187 histopathological sections and corresponding OCT-NIRAF images from 13 cadaver coronary arteries from 5 patients were imaged and analyzed. Several LRP that were identified by histopathology in these arteries showed regions with evidence of necrotic core with hemosiderin granules that had significantly higher catheter-based NIRAF than regions without hemosiderin granules. Confocal NIRAF microscopy also showed that regions of high NIRAF were associated with accumulation of hemosiderin in corresponding histological sections. Conclusions: This study provides suggestive data that an integrated OCT-NIRAF imaging system and catheter may be able to be used to identify advanced LRP that contains a necrotic core with hemosiderin granules. Future investigation of NIRAF from cadaver arteries from additional patients is merited to robustly confirm these findings.

Autofluorescence imaging for improved visualization of joint structures during arthroscopic surgery

BackgroundThe purpose of our study is to develop the arthroscopic autofluorescence imaging (AFI) system to improve the visualization during arthroscopic surgery by real-time enhancing the contrast between joint structures with autofluorescence imaging. Its validity was evaluated around the arthroscopic anterior cruciate ligament (ACL) reconstruction, specifically improving the contrast between the femoral insertion site and its background. The feasibility of the AFI system was validated with bovine and human knees. The spectral responses of the femoral insertion site and its surrounding bone and cartilage were measured with a fluorospectrometer. A prototype of the AFI system was developed based on the spectral responses (SR) and test images of the insertion site. The accuracy was validated by evaluating the overlap between manually segmented insertion sites on the white light color images and on the corresponding spectral unmixed autofluorescence images. The final prototype of the AFI system was tested during arthroscopy in cadaveric knees.ResultsThe results showed that the joint structures have different SRs. Spectral unmixing enabled separation of the SRs and improved the contrast between the joint structures. The agreement between visible light and autofluorescence ligament insertions had a mean Dice coefficient of 0.84 and the mean Dice coefficient of the interobserver variability for visible light imaging was 0.85.ConclusionsWe have shown that the femoral insertion site can be accurately visualized with autofluorescence imaging combined with spectral unmixing. The AFI system demonstrates the feasibility of real-time and subject-specific visualization of the femoral insertion site which can facilitate anatomic ACL reconstruction. In addition, the AFI system can facilitate arthroscopic procedures in other joints and can also be used as a diagnostic tool.

Effectiveness of color intensity analysis using updated autofluorescence imaging systems for serrated lesions.

We previously reported the effectiveness of color intensity analysis using autofluorescence imaging (AFI) for differentiating colorectal neoplastic lesions from non-neoplastic lesions. However, the ability of AFI systems for differentiating serrated lesions has not been evaluated. In the present study, we assessed the effectiveness of color intensity analysis using updated AFI systems for evaluating serrated lesions. We retrospectively reviewed the data for 48 consecutive patients with 87 serrated lesions that were examined using updated AFI systems and resected at Jikei University Hospital. The mean green/red (G/R) ratio, which is obtained by dividing the mean green color intensities by the mean red color intensities, was calculated for each serrated lesion and compared between hyperplastic polyps, sessile serrated adenomas/polyps (SSA/P) with cytological dysplasia, and SSA/P without cytological dysplasia. We also assessed the area under the receiver operating characteristic curve (AUC) for determining SSA/P (both with and without cytological dysplasia) and SSA/P with cytological dysplasia. The AUC for determining SSA/P was 0.68; however, the AUC for determining SSA/P with cytological dysplasia was 0.97. With a cut-off for the G/R ratio of <0.93, the sensitivity, specificity, positive predictive value, and negative predictive value for SSA/P with cytological dysplasia were 95.5%, 91.0%, 77.8%, and 98.3%, respectively. Color intensity analysis of serrated lesions using updated AFI systems could effectively distinguish SSA/P with cytological dysplasia from hyperplastic polyps and SSA/P without cytological dysplasia.

Endoscopic diagnosis of colorectal serrated lesions: Current status and future perspectives based on the results of a questionnaire survey.

Serrated lesions, especially sessile serrated adenoma/polyps (SSA/P) are considered one of the most important precursors of colorectal cancers. However, it is still difficult to endoscopically differentiate SSA/P from hyperplastic polyps. In the present review, we mainly focus on the current status and future perspectives of endoscopic diagnosis of colorectal serrated lesions based on the results of a questionnaire survey and report from the Endoscopic Forum Japan (EFJ) 2015 held in Tokyo in August 2015. The proposed diagnostic strategy recommended for colorectal serrated lesions is as follows. (i) For detection, use of an updated image-enhanced endoscopy system including autofluorescence imaging (AFI) and narrow-band imaging (NBI) may be promising. (ii) For differential diagnosis (hyperplastic polyp or SSA/P) of diminutive, small and large serrated lesions, NBI with magnification and magnifying chromoendoscopy using both indigocarmine and crystal violet should be applied, respectively. (iii) For differential diagnosis of SSA/P (with or without cytological dysplasia), magnifying chromoendoscopy, endocytoscopy and updated AFI system modalities might be promising.

Autofluorescence imaging system to discriminate and quantify the distribution of benthic cyanobacteria and diatoms

AbstractObservation of benthic photoautotrophs on sediment surfaces shows a single algal layer without distinction between photosynthetic groups. Until now it has not been possible to distinguish between benthic photosynthetic microorganisms, i.e. cyanobacteria and diatoms, at μm to mm scales using a single nondisruptive system. Chlorophyll autofluorescence can be used to distinguish different photoautotrophic groups if the correct excitation light is applied. Using this principle, a nonintrusive technique was developed to study the spatial distribution of benthic cyanobacteria and diatoms. By means of a charge coupled device camera, diatoms and cyanobacteria could be identified by blue light (470 nm) excitation and amber light (600 nm) excitation, respectively. By this approach, diatom or cyanobacterial dominance could be easily distinguished using the blue over amber ratio. We applied this method successfully to (mixed) laboratory cultures as well as natural photosynthetic microbial mats. Cultures of the diatom Nitzschia capitellata and the cyanobacterium Geitlerinema sp. showed close correlation between autofluorescence and cell abundance. This simple and cheap imaging system allows fast observations of the fine‐scale (μm–mm) spatial heterogeneities of live benthic microbial photoautotrophs both in culture and natural photosynthetic biofilms structure (e.g., microphytobenthos and photosynthetic microbial mats). © 2014 Association for the Sciences of Limnology and Oceanography

Photodynamic diagnosis of pleural malignant lesions with a combination of 5-aminolevulinic acid and intrinsic fluorescence observation systems.

BackgroundWe have developed a new diagnostic method using the photosensitizer 5-aminolevulinic acid (5ALA) for diagnosing intrathoracic malignant lesions. When ingested exogenously, 5ALA is metabolized to a heme precursor, protoporphyrin IX, which stays in malignant cells and emits red to pink luminescence of about 630 nm.MethodsWe enrolled 40 patients who underwent respiratory surgery and consented to participate in this study. Twenty-eight patients had primary lung cancer, 8 metastatic lung tumors, 2 malignant pleural tumors, and 2 benign tumors. Localization of malignant lesions was attempted by observing such lesions with an autofluorescence imaging system and by comparing the color tone of the autofluorescence between malignant lesions and normal tissues after oral administration of 5ALA. Malignant lesions on the pleural surface emitted pink autofluorescence in contrast to the green autofluorescence of the surrounding normal tissues.ResultsWhen 28 patients with primary lung cancer were examined according to the degree of pleural infiltration (pl), red fluorescence was confirmed in 10 of 10 patients (100%) with p11-p13 and 5 of 18 patients (27.7%) with p10. The latter 5 patients had been diagnosed with PL1 preoperatively or intraoperatively.ConclusionThis system achieved accurate localization of malignant lesions, suggesting that it may also be applicable to photodynamic therapy.

Visualization of colorectal neoplasia by a second-generation autofluorescence imaging system

Objective. Autofluorescence imaging (AFI) systems may allow better visualization of colorectal neoplasia than conventional methods. However, this is difficult to demonstrate objectively. Recently, a second-generation AFI system with a noise-reduction algorithm was developed. We aimed to objectively evaluate the visualization of colorectal neoplasia by using a second-generation AFI system and software to calculate the color-contrast index. Material and methods. We retrospectively reviewed 53 consecutive colorectal neoplasias examined using the second-generation AFI system. Color-contrast indices between the colorectal lesions and the surrounding normal mucosa in the WLI, AFI and NBI images were calculated. The WLI, AFI, NBI and CE images were also evaluated by endoscopists using questionnaire-based visualization scores. Results. The color-contrast index seen in the AFI images (33.74 ± 9.20) was significantly higher than that in either the WLI (11.14 ± 6.14) or NBI images (11.72 ± 7.12). There was no significant difference between the color-contrast indices of the WLI and NBI images. The mean AFI image visualization score (6.7 ± 1.8) was significantly higher than that of WLI (6.0 ± 1.7), and tended to be higher than that of the NBI images (6.1 ± 1.6) when assessed by less-experienced endoscopists. Conclusions. This study objectively demonstrates that compared to WLI and NBI, the second-generation AFI system enables superior visualization of colorectal neoplasms. The visualization scores were higher for the AFI images when evaluated by less-experienced endoscopists. These results indicate that the second-generation AFI system may aid less-experienced endoscopists in the detection of colorectal neoplasia.

Tu1463 Visualization of Colorectal Neoplasia by a Novel Autofluorescence Imaging System

Autofluorescence Imaging (AFI) systems may allow better visualization of colorectal neoplasia. However, this is difficult to demonstrate objectively. Recently, a novel AFI system (EVIS LUCERA ELITE, Olympus Medical Systems, Tokyo, Japan) with a noise-reduction algorithm was developed that enabled the generation of higher resolution images.

Tu1474 Usefulness of a Novel Auto-Fluorescence Imaging System With Computer-Assisted Color Analysis for Colorectal Lesions

We have reported the effectiveness of AFI (auto-fluorescence imaging) systems in distinguishing colorectal non-neoplastic lesions from neoplastic lesions. Recently, a novel high-resolution AFI system (EVIS LUCERA ELITE; Olympus Medical Systems, Tokyo, Japan) and software that enables “real-time” color analysis were developed.

Efficacy of a novel auto-fluorescence imaging system with computer-assisted color analysis for assessment of colorectal lesions

To evaluate the efficacy of computer-assisted color analysis of colorectal lesions using a novel auto-fluorescence imaging (AFI) system to distinguish neoplastic lesions from non-neoplastic lesions and to predict the depth of invasion. From January 2013 to April 2013, consecutive patients with known polyps greater than 5 mm in size who were scheduled to undergo endoscopic treatment at The Jikei University Hospital were prospectively recruited for this study. All lesions were evaluated using a novel AFI system, and color-tone sampling was performed in a region of interest determined from narrow band imaging or from chromoendoscopy findings without magnification. The green/red (G/R) ratio for each lesion on the AFI images was calculated automatically using a computer-assisted color analysis system that permits real-time color analysis during endoscopic procedures. A total of 88 patients with 163 lesions were enrolled in this study. There were significant differences in the G/R ratios of hyperplastic polyps (non-neoplastic lesions), adenoma/intramucosal cancer/submucosal (SM) superficial cancer, and SM deep cancer (P < 0.0001). The mean ± SD G/R ratios were 0.984 ± 0.118 in hyperplastic polyps and 0.827 ± 0.081 in neoplastic lesions. The G/R ratios of hyperplastic polyps were significantly higher than those of neoplastic lesions (P < 0.001). When a G/R ratio cut-off value of > 0.89 was applied to determine non-neoplastic lesions, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 83.9%, 82.6%, 53.1%, 95.6% and 82.8%, respectively. For neoplastic lesions, the mean G/R ratio was 0.834 ± 0.080 in adenoma/intramucosal cancer/SM superficial cancer and 0.746 ± 0.045 in SM deep cancer. The G/R ratio of adenoma/intramucosal cancer/SM superficial cancer was significantly higher than that of SM deep cancer (P < 0.01). When a G/R ratio cut-off value of < 0.77 was applied to distinguish SM deep cancers, the sensitivity, specificity, PPV, NPV, and accuracy were 80.0%, 84.4%, 29.6%, 98.1% and 84.1%, respectively. The novel AFI system with color analysis was effective in distinguishing non-neoplastic lesions from neoplastic lesions and might allow determination of the depth of invasion.