Advanced endoscopic methods in gastrointestinal diseases: a systematic review

Spatial-attention ConvMixer architecture for classification and detection of gastrointestinal diseases using the Kvasir dataset

Gastrointestinal (GI) disorders, encompassing conditions like cancer and Crohn's disease, pose a significant threat to public health. Endoscopic examinations have become crucial for diagnosing and treating these disorders efficiently. However, the subjective nature of manual evaluations by gastroenterologists can lead to potential errors in disease classification. In addition, the difficulty of diagnosing diseased tissues in GI and the high similarity between classes made the subject a difficult area. Automated classification systems that use artificial intelligence to solve these problems have gained traction. Automatic detection of diseases in medical images greatly benefits in the diagnosis of diseases and reduces the time of disease detection. In this study, we suggested a new architecture to enable research on computer-assisted diagnosis and automated disease detection in GI diseases. This architecture, called Spatial-Attention ConvMixer (SAC), further developed the patch extraction technique used as the basis of the ConvMixer architecture with a spatial attention mechanism (SAM). The SAM enables the network to concentrate selectively on the most informative areas, assigning importance to each spatial location within the feature maps. We employ the Kvasir dataset to assess the accuracy of classifying GI illnesses using the SAC architecture. We compare our architecture's results with Vanilla ViT, Swin Transformer, ConvMixer, MLPMixer, ResNet50, and SqueezeNet models. Our SAC method gets 93.37% accuracy, while the other architectures get respectively 79.52%, 74.52%, 92.48%, 63.04%, 87.44%, and 85.59%. The proposed spatial attention block improves the accuracy of the ConvMixer architecture on the Kvasir, outperforming the state-of-the-art methods with an accuracy rate of 93.37%.

Clinical issues and challenges in imaging of gastrointestinal diseases: A minireview and our experience

Imaging techniques play a crucial role in the modern era of medicine, particularly in gastroenterology. Nowadays, various non-invasive and invasive imaging modalities are being routinely employed to evaluate different gastrointestinal (GI) diseases. However, many instrumental as well as clinical issues are arising in the area of modern GI imaging. This minireview article aims to briefly overview the clinical issues and challenges encountered in imaging GI diseases while highlighting our experience in the field. We also summarize the advances in clinically available diagnostic methods for evaluating different diseases of the GI tract and demonstrate our experience in the area. In conclusion, almost all imaging techniques used in imaging GI diseases can also raise many challenges that necessitate careful consideration and profound expertise in this field.

Systematic analysis of levels of evidence supporting Chinese clinical practice guidelines for gastrointestinal disease

BACKGROUND

Clinical practice guidelines (CPGs) inform healthcare decisions and improve patient care. However, an evaluation of guidelines on gastrointestinal diseases (GIDs) is lacking. This study aimed to systematically analyze the level of evidence (LOE) supporting Chinese CPGs for GIDs.

METHODS

CPGs for GIDs were identified by systematically searching major databases. Data on LOEs and classes of recommendations (CORs) were extracted. According to the Grades of Recommendation, Assessment, Development, and Evaluation system, LOEs were categorized as high, moderate, low, or very low, whereas CORs were classified as strong or weak. Statistical analyses were conducted to determine the distribution of LOEs and CORs across different subtopics and assess changes in evidence quality over time.

FINDINGS

Only 27.9% of these recommendations were supported by a high LOE, whereas approximately 70% were strong recommendations. There was a significant disparity among different subtopics in the proportion of strong recommendations supported by a high LOE. The number of guidelines has increased in the past 5 years, but there has been a concomitant decline in the proportion of recommendations supported by a high LOE.

CONCLUSIONS

There is a general lack of high-quality evidence supporting Chinese CPGs for GIDs, and there are inconsistencies in strong recommendations that have not improved. This study identified areas requiring further research, emphasizing the need to bridge these gaps and promote the conduct of high-quality clinical trials.

FUNDING

This study was supported by the National Key R&D Program of China (2022YFC2503604 and 2022YFC2503605) and Special Topics in Military Health Care (22BJZ25).

Simultaneous photoacoustic and ultrasound imaging: A review

Photoacoustic imaging (PAI) is an emerging biomedical imaging technique that combines the advantages of optical and ultrasound imaging, enabling the generation of images with both optical resolution and acoustic penetration depth. By leveraging similar signal acquisition and processing methods, the integration of photoacoustic and ultrasound imaging has introduced a novel hybrid imaging modality suitable for clinical applications. Photoacoustic-ultrasound imaging allows for non-invasive, high-resolution, and deep-penetrating imaging, providing a wealth of image information. In recent years, with the deepening research and the expanding biomedical application scenarios of photoacoustic-ultrasound bimodal systems, the immense potential of photoacoustic-ultrasound bimodal imaging in basic research and clinical applications has been demonstrated, with some research achievements already commercialized. In this review, we introduce the principles, technical advantages, and biomedical applications of photoacoustic-ultrasound bimodal imaging techniques, specifically focusing on tomographic, microscopic, and endoscopic imaging modalities. Furthermore, we discuss the future directions of photoacoustic-ultrasound bimodal imaging technology.

Global prevalence of functional dyspepsia according to Rome criteria, 1990-2020: a systematic review and meta-analysis

Although functional dyspepsia (FD) is a common functional gastroduodenal disorder with a high socioeconomic burden, little is known about its global prevalence. Thus, we performed a comprehensive study to estimate long-term trends in the prevalence of FD. We searched PubMed/MEDLINE, Embase, and Google Scholar from 1990 to 2022 for population-based studies that reported the prevalence of FD in adults (≥ 18 years old) according to Rome I, II, III, or IV criteria. The prevalence of FD was extracted from included studies to obtain pooled prevalence with 95% confidence intervals (CI) and 95% prediction intervals. Subgroup analysis was performed according to certain characteristics, including geographic region. A total of 44 studies met the eligibility criteria, including 256,915 participants from 40 countries across six continents. The overall global pooled prevalence of FD was 8.4% (95% CI 7.4-.9.5). The prevalence was the highest in Rome I (11.9%; 95% CI 5.1-25.4) and lowest in Rome IV (6.8%; 95% CI 5.8-7.9). Developing countries showed a higher prevalence than developed countries (9.1% versus 8.0%), and prevalence was higher in women, irrespective of the definition used (9.0% versus 7.0%). The pooled prevalence gradually decreased from 1990 to 2020 (12.4% [8.2-18.3] in 1990-2002 versus 7.3% [6.1-8.7] in 2013-2020). The prevalence of FD differs by country, economic status, geographical region, and sex, and the global prevalence has been gradually declining. Despite the heterogeneity of sample population, our study estimates the current global burden of FD and provides information to heath care policy decisions.

Application of near-infrared fluorescence imaging in theranostics of gastrointestinal tumors

Gastrointestinal cancers have become an important cause of cancer-related death in humans. Improving the early diagnosis rate of gastrointestinal tumors and improving the effect of surgical treatment can significantly improve the survival rate of patients. The conventional diagnostic method is high-definition white-light endoscopy, which often leads to missed diagnosis. For surgical treatment, intraoperative tumor localization and post-operative anastomotic state evaluation play important roles in the effect of surgical treatment. As a new imaging method, near-infrared fluorescence imaging (NIRFI) has its unique advantages in the diagnosis and auxiliary surgical treatment of gastrointestinal tumors due to its high sensitivity and the ability to image deep tissues. In this review, we focus on the latest advances of NIRFI technology applied in early diagnosis of gastrointestinal tumors, identification of tumor margins, identification of lymph nodes, and assessment of anastomotic leakage. In addition, we summarize the advances of NIRFI systems such as macro imaging and micro imaging systems, and also clearly describe the application process of NIRFI from system to clinical application, and look into the prospect of NIRFI applied in the theranostics of gastrointestinal tumors.

Indocyanine Green (ICG) and Colorectal Surgery: A Literature Review on Qualitative and Quantitative Methods of Usage

Background: Due to its many benefits, indocyanine green (ICG) has gained progressive popularity in operating rooms (ORs) globally. This literature review examines its qualitative and quantitative usage in surgical treatment. Method: Relevant terms were searched in five international databases (1. Pubmed, 2. Sciencedirect, 3. Scopus, 4. Oxfordjournals, 5. Reaxys) for a comprehensive literature review. The main benefits of using ICG in colorectal surgery are: intraoperative fluorescence angiography; fluorescence-guided lymph node involvement detection and the sentinel technique; the fluorescent emphasis of a minute liver tumour, counting just 200 tumour cells; facilitation of fistula diagnosis; and tumour tattooing. This methodology can also be used with quantitative characteristics such as maximum intensity, relative maximum intensity, and in-flow parameters such as time-to-peak, slope, and t1/2max. This article concludes that fluorescence surgery with ICG and near-infrared (NIR) light is a relatively new technology that improves anatomical and functional information, allowing more comprehensive and safer tumour removal and the preservation of important structures.

Advances in Pediatric Diagnostic Endoscopy: A State-of-the-Art Review

Pediatric endoscopy has revolutionized the way we diagnose and treat gastrointestinal disorders in children. Technological advances in computer processing and imaging continue to affect endoscopic equipment and advance diagnostic tools for pediatric endoscopy. Although commonly used by adult gastroenterologists, modalities, such as endomicroscopy, image-enhanced endoscopy, and impedance planimetry, are not routinely used in pediatric gastroenterology. This state-of-the-art review describes advances in diagnostic modalities, including image-enhanced endoscopy, confocal laser endomicroscopy, optical coherence tomography, endo functional luminal imaging probes, wireless motility/pH capsule, wireless colon capsule endoscopy, endoscopic ultrasound, and discusses the basic principles of each technology, including adult indications and pediatric applications, safety cost, and training data.

Optical Resolution Photoacoustic Microscopy Imaging in the Detection of Early Oral Cancer under Image Reconstruction Algorithm

This research was intended to explore the application value of photoacoustic imaging technology based on image intelligent iterative reconstruction algorithm in the detection and diagnosis of early oral cancer. An iterative algorithm model was constructed and systematically analyzed. The algorithm was used to debug the detection of B-scan images on the diameter of the imaging area. The results showed that the sensitivity of line-focused ultrasound detector was 86.72% and the specificity was 80.79%, while the sensitivity of the flat-field ultrasound detector was 63.15% and the specificity was 71.79%. The photoacoustic microscopy imaging technology can clearly observe the rich capillary network on human lips. A part of the vascular network at the depth of 100 μm, 500 μm, and 1000 μm grew out of the reticular capillaries and extended out of the loop-like capillaries, and the diameter gradually expanded. The imaging experiment of the sublingual capillary network in the human body showed that loop-like capillaries were observed, but there were some large blood vessels, which corresponded to the densely distributed blood vessel network under the tongue. The morphological changes of loop-like capillaries can be well observed by photoacoustic microscopy. In conclusion, the reconstructed photoacoustic microscopy imaging technology can realize high-resolution imaging of human oral capillaries and observe the morphological changes of loop-like capillaries, which had a certain application value for the early detection of oral cancer.

Analysis of the Influence of Comprehensive Nursing Intervention on Vital Signs and Negative Emotions of Patients with Gastrointestinal Polyps Treated by Digestive Endoscopy

This research sets out to elucidate the influence of comprehensive nursing intervention (CNI) on vital signs (VSs) and negative emotions (NEs) of patients with gastrointestinal polyps treated by digestive endoscopy. To address this, from January 2020 to February 2021, 92 cases of gastrointestinal polyps treated by digestive endoscopy in the Yuyao People's Hospital of Zhejiang Province were partitioned into two different groups: the control group (CG; n = 46) intervened by routine nursing intervention, and the research group (RG; n = 46) treated by CNI based on routine care. The VSs, NEs, time of first postoperative exhaust and defecation, early food intake, length of stay (LOS), quality of life (QOL), nursing satisfaction, and the incidence of postoperative complications were compared between groups. When entering the operating room, elevated systolic/diastolic (SBP/DBP) was observed in CG compared with RG (P < 0.05) while there was no statistical difference in SBP/DBP in RG before intervention and when entering the operating room (P > 0.05). Statistically, less time of first exhaust and defecation as well as LOS and early food intake were observed in RG (P < 0.05). The HAMA and HAMD scores declined in both arms postintervention, and the decrease was more obvious in RG (P < 0.05). After intervention, the scores of various domains of GQOLI-74 elevated in both arms, and the increase was more obvious in RG (P < 0.05). RG also showed a lower total complication rate and a higher degree of nursing satisfaction than CG (P < 0.05). CNI for patients with gastrointestinal polyps treated by digestive endoscopy can obviously relieve their anxiety and depression, with stable VSs, short LOS, and low incidence of complications.

Lessons learned: Preventable misses and near-misses of endoscopic procedures

Endoscopy is a complex procedure that requires advanced training and a highly skilled practitioner. The advances in the field of endoscopy have made it an invaluable diagnostic tool, but the procedure remains provider dependent. The quality of endoscopy may vary from provider to provider and, as a result, is not perfect. Consequently, 11.3% of upper gastrointestinal neoplasms are missed on the initial upper endoscopy and 2.1%-5.9% of colorectal polyps or cancers are missed on colonoscopy. Pathology is overlooked if endoscopic exam is not done carefully, bypassing proper visualization of the scope’s entry and exit points or, if exam is not taken to completion, not visualizing the most distal bowel segments. We hope to shed light on this issue, establish areas of weakness, and propose possible solutions and preventative measures.

No-reference image quality assessment for confocal endoscopy images with perceptual local descriptor

SIGNIFICANCE

Confocal endoscopy images often suffer distortions, resulting in image quality degradation and information loss, increasing the difficulty of diagnosis and even leading to misdiagnosis. It is important to assess image quality and filter images with low diagnostic value before diagnosis.

AIM

We propose a no-reference image quality assessment (IQA) method for confocal endoscopy images based on Weber's law and local descriptors. The proposed method can detect the severity of image degradation by capturing the perceptual structure of an image.

APPROACH

We created a new dataset of 642 confocal endoscopy images to validate the performance of the proposed method. We then conducted extensive experiments to compare the accuracy and speed of the proposed method with other state-of-the-art IQA methods.

RESULTS

Experimental results demonstrate that the proposed method achieved an SROCC of 0.85 and outperformed other IQA methods.

CONCLUSIONS

Given its high consistency in subjective quality assessment, the proposed method can screen high-quality images in practical applications and contribute to diagnosis.

Deep Learning Methods for Anatomical Landmark Detection in Video Capsule Endoscopy Images

Video capsule endoscope (VCE) is an emerging technology that allows examination of the entire gastrointestinal (GI) tract with minimal invasion. While traditional endoscopy with biopsy procedures are the gold standard for diagnosis of most GI diseases, they are limited by how far the scope can be advanced in the tract and are also invasive. VCE allows gastroenterologists to investigate GI tract abnormalities in detail with visualization of all parts of the GI tract. It captures continuous real time images as it is propelled in the GI tract by gut motility. Even though VCE allows for thorough examination, reviewing and analyzing up to eight hours of images (compiled as videos) is tedious and not cost effective. In order to pave way for automation of VCE-based GI disease diagnosis, detecting the location of the capsule would allow for a more focused analysis as well as abnormality detection in each region of the GI tract. In this paper, we compared four deep Convolutional Neural Network models for feature extraction and detection of the anatomical part within the GI tract captured by VCE images. Our results showed that VGG-Net has superior performance with the highest average accuracy, precision, recall and, F1-score compared to other state of the art architectures: GoogLeNet, AlexNet and, ResNet.

Endoscopic Advances for Gastric Neoplasia Detection

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

Taking the Next Steps in Endoscopic Visual Assessment of Barrett's Esophagus: A Pilot Study

Purpose

Patients with Barrett's esophagus (BE) undergo surveillance endoscopies to assess for pre-cancerous changes. We developed a simple endoscopic classification method for predicting non-dysplastic BE (NDBE), low-grade dysplasia (LGD)/indefinite for dysplasia (ID) and high-grade dysplasia (HGD)/early esophageal adenocarcinoma (EAC).

Patients and Methods

Twenty-two patients with BE underwent endoscopy using the PENTAX Medical MagniView gastroscope and OPTIVISTA processor. Sixty-six video-still images were analyzed to characterize the microsurface, microvasculature and the presence of a demarcation line. Class A was characterized by regular microvascular and microsurface patterns and absence of a demarcation line, class B by changes in the microvascular and/or microsurface patterns compared to the background mucosa with presence of a demarcation line, and class C by irregular microvascular and/or irregular microsurface patterns with presence of a demarcation line.

Results

Of the class A images, 97.9% were NDBE. For class B, 69.2% were LGD/ID and 30.8% NDBE. One hundred percent of the class C samples were HGD/EAC. The sensitivity of our classification system was 93.8%, specificity 92%, positive predictive value 78.9%, negative predictive value 97.9% and an accuracy 92.4%.

Conclusion

In this study, we developed a simple classification system for the prediction of NDBE, LGD/ID and HGD/EAC. Its real-time clinical applicability will be validated prospectively.

Effect of endoscope flexibility on tissue dissection profile assessed with pulsed water jet device: ensuring safety, efficacy, and handling of thin devices for neuroendoscopic surgery

Objective

We developed an actuator-driven pulsed water jet device (ADPJ) for flexible neuroendoscopy to achieve effective tissue dissection with vasculature preservation. Although flexibility is a strong advantage for minimally invasiveness, the effect of the ductile curvature on the dissection profiles remains unknown. The purpose of this study was to clarify the impact of the curvature change of the ADPJ connecting tube on the dissection safety and efficacy.

Results

Three ADPJ connecting tubes with different inner diameters (1.0, 0.75, 0.5 mm) were used to dissect the brain phantom. They were bent at 3 angles: 0°, 60°, and 120°. The dissection profiles were evaluated using the mean depth and coefficient of variation (CV) for efficacy and safety, respectively.The larger inner diameter connecting tube dissected more deeply. The dissection depth was not changed regardless of the curvature degree in each tube. There was no significant difference in CVs regardless of inner diameter and curvature. The ductile curvature of the flexible neuroendoscope did not affect the efficacy and safety of the ADPJ dissection profile. Among the numerous instruments, tube-formed devices, including suction and injecting devices such as ADPJ, can be used safely and effectively without flexibility-related limitations.

3D acoustic resolution-based photoacoustic endoscopy with dynamic focusing

Background

Acoustic resolution-based photoacoustic endoscopy (ARPAE) is a non-invasive potential tool for imaging gastrointestinal and urogenital tracts. However, current ARPAE systems usually only provide 2D sectorial B-mode images, and have the limitation of the image quality significantly deteriorating out-of-focus regions due to transducers with fixed focus in these systems. To overcome these limitations, we put forward a modified back-projection method that can provide 3D images with dynamic focusing in ARPAE.

Methods

A graphics processing unit (GPU)-based parallel computation technique was adopted for efficient computation. Both simulated and phantom/ex-vivo experiments were conducted to validate our method.

Results

The findings indicated that our proposed method can effectively improve the lateral resolution and signal-to-noise ratio (SNR) in the out-of-focus regions. For a target 3 mm from the transducer focus, the new method can improve 11 times in the lateral resolution, along with an improvement of up to 37 dB in the SNR.

Conclusions

3D ARPAE provides high-quality imaging in both focus and out-of-focus regions.

The Landscape of Interactions between Hypoxia-Inducible Factors and Reactive Oxygen Species in the Gastrointestinal Tract

The gastrointestinal tract (GT) is the major organ involved in digestion, absorption, and immunity, which is prone to oxidative destruction by high levels of reactive oxygen species (ROS) from luminal oxidants, such as food, drugs, and pathogens. Excessive ROS will lead to oxidative stresses and disrupt essential biomolecules, which also act as cellular signaling molecules in response to growth factors, hormones, and oxygen tension changes. Hypoxia-inducible factors (HIFs) are critical regulators mediating responses to cellular oxygen tension changes, which are also involved in energy metabolism, immunity, renewal, and microbial homeostasis in the GT. This review discusses interactions between HIF (mainly HIF-1α) and ROS and relevant diseases in the GT combined with our lab's work. It might help to develop new therapies for gastrointestinal diseases associated with ROS and HIF-1α.

The Effectiveness of Drying on Residual Droplets, Microorganisms, and Biofilms in Gastrointestinal Endoscope Reprocessing: A Systematic Review

BACKGROUND

Despite endoscope reprocessing, residual droplets remain in gastrointestinal endoscope working channels. Inadequate drying of gastrointestinal endoscope working channels may promote microbial reproduction and biofilm formation, increasing the risk of infection in patients. This review was designed to provide the current status of gastrointestinal endoscope drying, emphasize the importance of gastrointestinal endoscope drying, and evaluate the effectiveness of different drying methods of gastrointestinal endoscope in reducing residual droplets and microbial growth risk.

METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting checklist. The PubMed, Web of Science, Medline, EMBASE, EBSCO, CNKI, CQVIP, and Wanfang Data databases were searched from 2010 to 2020 to identify eligible articles focused on methods of gastrointestinal endoscope drying and the status of endoscope drying. The following key points were analyzed: type of intervention, amount of residual droplets, major microbial types, and effectiveness of biofilm intervention. JBI quality assessment tool was used to determine bias risk for inclusion in the article.

RESULTS

This review included twelve articles. Two of the articles reported lack of drying of gastrointestinal endoscopes while the other ten reported residual droplets, microbial growth, and biofilm formation after different methods of drying. Four articles reported 0 to 4.55 residual droplets; four articles reported that the main microbial types were cocci and bacilli, most commonly Staphylococcus, Escherichia coli, Bacillus maltophilia, and Pseudomonas aeruginosa; and two reported that drying could effectively reduce biofilm regeneration. The type of intervention is as follows: automatic endoscopy reprocessor (AER), manual compressed air drying, and the Dri-Scope Aid for automatic drying and drying cabinet.

CONCLUSIONS

While endoscope reprocessing may not always be effective, an automatic endoscope reprocessor plus the Dri-Scope Aid with automatic drying over 10 min or storage in a drying cabinet for 72 h may be preferred.

Value of endoscopy with narrow-band imaging and probe-based confocal laser endomicroscopy in the diagnosis of preneoplastic lesions of gastrointestinal tract

INTRODUCTION

Amongst all malignant tumors, cancers of the digestive tract rank first in terms of yearly deaths. Patients above 60 years of age are the most affected, as the diagnosis is frequently made in advanced stages of the disease when therapy is less effective. Our study aimed to evaluate the efficiency of narrow-band imaging (NBI) endoscopy and probe-based confocal laser endomicroscopy (pCLE) in the correct diagnosis of preneoplastic lesions in the upper and lower digestive tract.

PATIENTS, MATERIALS AND METHODS

We included 46 patients with digestive preneoplastic lesions, who underwent either upper or lower digestive endoscopy, followed by NBI and pCLE. We recorded 5-10 frames per each lesion, from different angles and distances during white-light endoscopy and selected frames from full recordings of NBI and pCLE. Usual preparation was used for the endoscopic procedures; pCLE required in vivo administration of 10% Sodium Fluorescein as a contrast agent. Pathology was performed in case of solid tumors. Three medical professionals with different levels of training, blinded to the results, interpreted the data.

RESULTS

The experienced physician correlated very well the NBI findings with pathology (0.93, p=0.05), while the resident physician and the experienced nurse obtain lower, albeit still statistically significant, values (0.73 and 0.62, respectively). For pCLE, the experienced physician obtained near-perfect correlation with pathology (0.96), followed closely by the resident physician (0.93). The nurse obtained a modest correlation (0.42). All examiners obtained approximately equal performances in discerning between malignant and benign lesions.

CONCLUSIONS

Digestive endoscopy in NBI mode proved its effectiveness. Even less experienced endoscopists can achieve good results, while an experienced nurse can positively influence the diagnosis. In the case of pCLE, when available, it can greatly reduce diagnostic times, while requiring higher expertise and specialty training.

Optical coherent tomography to evaluate the degree of inflammation in a mouse model of colitis

Background

There is an urgent need to develop a noninvasive imaging technique for the diagnosis of early inflammatory lesions or early and real-time microscopic assessment before selecting the most representative biopsy sites.

Methods

In this study, a dextran sulfate sodium colitis model was developed, and intestinal histological damage scores measured the degree of inflammation in colitis. According to these scores, 6 parameters were designed for hematoxylin and eosin (HE) sections based on morphological changes, and 2 parameters were designed for optical coherence tomography (OCT) images to measure submucosal edema by morphological changes to evaluate inflammation degrees in the colon. Spearman's rank correlation method was used to compare the correlation between the submucosal morphological changes and the different degrees of inflammation. One-way analysis of variance (ANOVA) was used for comparisons among groups, while receiver operating characteristic (ROC) curves of the indicators in HE sections and OCT images were plotted.

Results

In HE sections, angle of mucosal folds (r=0.853, P<0.01), length of basilar parts (r=0.915, P<0.01), submucosal area (r=0.819, P<0.01), and height between submucosal and muscular layers (r=0.451, P=0.001) were correlated with the degree of inflammation in colitis. In OCT images, length of basilar parts (r=0.800, P<0.01) and height of submucosa + thickness of muscularis (r=0.648, P=0.001) were correlated with the degree of inflammation and aided the measurement of inflammation in the colon.

Conclusions

Parameters based on morphological changes in OCT images and HE sections were significant indexes for evaluating the degree of inflammation in colitis. OCT images have advantages for future clinical applications in situ, including noninvasiveness and real-time imaging.