The five-year survival rate of gastric cancer in China is close to that in European and American countries but far lower than that in the Republic of Korea and Japan,which have established national gastric cancer screening systems.It is of great significance to build a high-quality gastric cancer screening system adaptive to China's national conditions.Due to the large number of people at risk of gastric cancer and uneven distribution of medical resources,it is still difficult for China to carry out a nationwide gastroscopy screening plan for gastric cancer.Gastric ultrasound,with painlessness,no radiation,and easy acceptance and popularization,could be used as one of the alternative methods for initial screening of gastric cancer.Based on two gastric ultrasound-related consensuses published in 2020,this consensus elaborates on the necessity,feasibility,and existing problems of conducting preliminary gastric cancer ultrasound screening in China by analyzing the gastric cancer screening strategies and the difficulties faced by nationwide gastric cancer screening.Furthermore,this consensus introduces the indications and contraindications of gastric ultrasound examination,requirements for the operator and the contrast agent,ultrasound standard section,essentials of scanning operations,and stomach ultrasound report and data system (Su-RADS) and proposes the relevant consensus opinions accordingly.After multiple rounds of discussions and voting by experts from multiple societies,a total of 17 consensus opinions have been formed on gastric ultrasound as a preliminary screening technique for gastric cancer,with the aim of standardizing the popularization of gastric ultrasound.In addition,the consensus calls for conducting nationwide multicenter prospective studies to improve the level of evidence and provide data support for the construction of a preliminary gastric cancer ultrasound screening system that is in line with China's national conditions.
Humans ; China ; Early Detection of Cancer/methods* ; Mass Screening ; Stomach/diagnostic imaging* ; Stomach Neoplasms/diagnostic imaging* ; Ultrasonography

Gastric contrast-enhanced ultrasound is a non-invasive imaging method that uses oral gastrointestinal ultrasound contrast agents to fill the stomach cavity and display the structure and lesions of the stomach wall.In recent years,the development of contrast agents and the technological innovations of ultrasound equipment have boosted the unique advantages of this examination technique in the diagnosis of gastrointestinal diseases.Gastric contrast-enhanced ultrasound is becoming an important complementary examination means to gastroscopy and X-ray barium meal examination.In this paper,we summarize the clinical applications of gastric contrast-enhanced ultrasound at home and abroad in recent years and systematically analyze its clinical application value and limitations in six aspects:screening and staging of gastric cancer,differentiation and diagnosis of gastric tumors,diagnosis and follow-up of gastritis and gastric ulcers,assessment of gastric contents and gastric volume,evaluation of gastric emptying and gastric motility,and other special applications.
Humans ; Contrast Media ; Ultrasonography/methods* ; Stomach/diagnostic imaging* ; Stomach Neoplasms/diagnostic imaging*

Gastric contrast-enhanced ultrasound includes oral contrast-enhanced ultrasound (OCUS) and double contrast-enhanced ultrasound (DCEUS),which can provide valuable clinical information about tumor morphology,vascular characteristics,and treatment responses.OCUS can clearly identify the gastric wall structure and the extent and depth of lesions by applying oral contrast agents.DCEUS,based on OCUS combined with venography,can display the anatomical and perfusion characteristics of lesions.In recent years,gastric contrast agents and imaging techniques have developed rapidly.However,the clinical application of gastric contrast-enhanced ultrasound is still in the developmental stage.This article reviews the clinical status of OCUS and DCEUS in the screening,diagnosis,staging,pathological typing,and treatment evaluation of gastric cancer.Studies have shown that gastric contrast-enhanced ultrasound has high sensitivity and specificity in the assessment of diagnosis and T-staging of gastric cancer.Furthermore,gastric contrast-enhanced ultrasound has the advantages of being cost-effective,convenient,non-invasive,free from radiation exposure,real-time,and easy to repeat.In the diagnosis and treatment of gastric cancer,it is expected to become one of the important imaging assessment tools.
Humans ; Stomach Neoplasms/diagnostic imaging* ; Contrast Media ; Ultrasonography/methods*

Gastric tumors are neoplastic lesions that occur in the stomach, posing a great threat to human health. Gastric cancer represents the malignant form of gastric tumors, and early detection and treatment are crucial for patient recovery. Endoscopic examination is the primary method for diagnosing gastric tumors. Deep learning techniques can automatically extract features from endoscopic images and analyze them, significantly improving the detection rate of gastric cancer and serving as an important tool for auxiliary diagnosis. This paper reviews relevant literature in recent years, presenting the application of deep learning methods in the classification, object detection, and segmentation of gastric tumor endoscopic images. In addition, this paper also summarizes several computer-aided diagnosis (CAD) systems and multimodal algorithms related to gastric tumors, highlights the issues with current deep learning methods, and provides an outlook on future research directions, aiming to promote the clinical application of deep learning methods in the endoscopic diagnosis of gastric tumors.
Humans ; Stomach Neoplasms/diagnostic imaging* ; Deep Learning ; Diagnosis, Computer-Assisted/methods* ; Gastroscopy/methods* ; Algorithms

Following with the development of individualized treatment of gastric cancer, the standardized radiological evaluation of gastric cancer is becoming more and more important. However,as a hollow viscera, the stomach is not fixed in shape and has a complex relationship with adjacent organs in the upper abdomen, which lead to the challenges in the radiological detection, localization, diagnosis and differential diagnosis, classification and staging, and evaluation of treatment response of gastric cancer. To deal with the challenges and address to clinical concerns, this consensus included the domestic experts on the frontline of clinical diagnosis and treatment of gastric cancer, and invited medical and surgical experts to participate in the inspection. The whole process was sorted out around five key points of gastric cancer radiological evaluation, including the selection of modalities, predisposal specification, examination standardization, reporting regulation and procedure in the participation of multidisciplinary team. All the experts voted by secret ballot to determine the level of evidence and recommendation. It is hoped that it can be used as a standard reference for radiological examination and diagnosis of gastric cancer.
Consensus ; Humans ; Stomach Neoplasms/diagnostic imaging*

Objective To investigate the value of ¹⁸F-FDG PET/CT metabolic parameters and metabolic heterogeneity for predicting the expression of human epidermal growth factor receptor 2 (HER2) in patients with gastric cancer. Methods A total of 45 patients with gastric cancer confirmed by surgical pathology between September 2016 and May 2021 were enrolled in this study.All the patients underwent ¹⁸F-FDG PET/CT examination before surgery.The maximum standardized uptake value (SUVmax),metabolic tumor volume (MTV),and total lesion glycolysis (TLG) of primary gastric cancer were measured,and the linear regression slope of MTV corresponding to different SUVmax thresholds (40% SUVmax and 80% SUVmax) was calculated.The absolute value of the slope was deemed to represent the metabolic heterogeneity of primary gastric cancer,termed the heterogeneity index (HI).Univariate and multivariate Logistic regression analyses were conducted to evaluate the correlations of ¹⁸F-FDG PET/CT metabolic parameters and HI with HER2 expression. Results The 45 patients included 10 with positive HER2 expression and 35 with negative result.The MTV (P=0.043) and HI (P=0.048) were lower in the patients with positive HER2 expression than in the patients with negative HER2 expression.The MTV and HI had the optimal thresholds of 12.10 cm³ and 3.71,respectively,which respectively showed the accuracy of 62.2% and 57.8% for predicting HER2 expression.The univariate Logistic regression showed that the tumor differentiation degree,MTV,and HI were correlated with HER2 expression,while the multivariate Logistic regression showed that only the tumor differentiation degree (OR=20.130,95%CI=1.843-219.860,P=0.014) was an independent predictor for HER2 expression.A further stratified analysis of the tumor differentiation degree showed that HER2 expression only varied among different MTV threshold groups in patients with moderately/well differentiated gastric cancer (P=0.031). Conclusions MTV and HI were associated with HER2 expression in gastric cancer,whereas neither played an independent predictive role.Therefore,these factors should be combined with clinicopathological characteristics of patients to jointly guide treatment decisions.
Fluorodeoxyglucose F18 ; Humans ; Positron Emission Tomography Computed Tomography/methods* ; Receptor, ErbB-2 ; Retrospective Studies ; Stomach Neoplasms/diagnostic imaging*

Objective: Anatomic variations in the perigastric vessels during laparoscopic radical gastrectomy often affect the operator's judgment and prolong the operation time, and even cause accidental injury and surgical complications, and hence the safety and quality of the operation cannot be ensured. In this study, multiple slice CT was reconstructed by 3-dimensional CT simulation software (3D-CT), and 3D-CT images were used to describe the variation of celiac trunk and splenic artery before surgery. The guiding role of the different variation of vessels was analyzed for laparoscopic total gastrectomy+D2 lymph node dissection (LTG+D2LD). Methods: A retrospective cohort study was conducted. Case inclusion criteria: (1) Gastric cancer was at an advanced stage. All the patients were preoperatively examined by digestive endoscopy and 64-row enhanced CT scan, and were histopathologically diagnosed with gastric adenocarcinoma. (2) 3D-CT simulation images were reconstructed to guide the operation. (3) LTG+D2LD surgery was performed by the same surgical team. (4) Clinical data were complete, and all the patients had signed the informed consent. From 2014 to 2018, 98 patients with gastric cancer at the Gastrointestinal Surgery Department of Henan Provincial People's Hospital were enrolled. According to the Adachi classification, celiac trunk variation was divided into common type (Adachi type I) and rare type (Adachi type II-VI). According to the Natsume classification, splenic artery was classified into "flat type" and "curved type". Based on 3D-CT simulation images, variation of celiac trunk and splenic artery was described, and the differences in operation time, intraoperative blood loss and the number of postoperative retrieved lymph nodes were compared between groups with different types of arterial variation. Results: For celiac trunk, common type was found in 84 cases (86%) and rare type was found in 14 cases, including 6 cases (6%) of type II, 2 cases (2%) of type III, 2 cases (2%) of type IV, 3 cases (3%) of type V, 1 case (1%) of type VI. No other types were found. There were no statistically significant differences in clinical characteristics and number of retrieved lymph nodes between patients of the common type group and rare type group (all P>0.05). Compared with common type patients, those of rare type had longer operative time [(321.1±29.0) minutes vs. (295.1±46.5) minutes, t=2.081, P=0.040] and more intraoperative blood loss (median: 66.0 ml vs. 32.0 ml, Z=-4.974, P=0.001). For splenic artery, 41 patients (42%) were flat type and 57 patients (58%) were curved type. There were no statistically significant differences between the two groups in terms of clinical characteristics, intraoperative blood loss, operative time and number of retrieved lymph nodes (all P>0.05). Conclusions: The method of describing the variation in the perigastric vessels by 3D-CT simulation has certain clinical value in laparoscopic radical gastrectomy. The duration of LTG+D2LD is prolonged and the intraoperative blood loss is increased with the variation of celiac trunk, while the variation of splenic artery has no effect on LTG+D2LD.
Computer Simulation ; Gastrectomy ; Gastric Artery/diagnostic imaging* ; Humans ; Imaging, Three-Dimensional ; Laparoscopy ; Lymph Node Excision ; Retrospective Studies ; Stomach/diagnostic imaging* ; Stomach Neoplasms/surgery* ; Tomography, X-Ray Computed

Objective: Contrast-enhanced CT is an important method of preoperative diagnosis and evaluation for the malignant potential of gastric submucosal tumor (SMT). It has a high diagnostic accuracy rate in differentiating gastric gastrointestinal stromal tumor (GIST) with a diameter greater than 5 cm from gastric benign SMT. This study aimed to use deep learning algorithms to establish a diagnosis model (GISTNet) based on contrast-enhanced CT and evaluate its diagnostic value in distinguishing gastric GIST with a diameter ≤ 5 cm and other gastric SMT before surgery. Methods: A diagnostic test study was carried out. Clinicopathological data of 181 patients undergoing resection with postoperative pathological diagnosis of gastric SMT with a diameter ≤ 5 cm at Department of Gastrointestinal Surgery of Renji Hospital from September 2016 to April 2021 were retrospectively collected. After excluding 13 patients without preoperative CT or with poor CT imaging quality, a total of 168 patients were enrolled in this study, of whom, 107 were GIST while 61 were benign SMT (non-GIST), including 27 leiomyomas, 24 schwannomas, 6 heterotopic pancreas and 4 lipomas. Inclusion criteria were as follows: (1) gastric SMT was diagnosed by contrast-enhanced CT before surgery; (2) preoperative gastroscopic examination and biopsy showed no abnormal cells; (3) complete clinical and pathological data. Exclusion criteria were as follows: (1) patients received anti-tumor therapy before surgery; (2) without preoperative CT or with poor CT imaging quality due to any reason; (3) except GIST, other gastric malignant tumors were pathologically diagnosed after surgery. Based on the hold-out method, 148 patients were randomly selected as the training set and 20 patients as the test set of the GISTNet diagnosis model. After the GISTNet model was established, 5 indicators were used for evaluation in the test set, including sensitivity, specificity, positive predictive value, negative predictive value and the area under the receiver operating curve (AUC). Then GISTNet diagnosis model was compared with the GIST-risk scoring model based on traditional CT features. Besides, in order to compare the accuracy of the GISTNet diagnosis model and the imaging doctors in the diagnosis of gastric SMT imaging, 3 radiologists with 3, 9 and 19 years of work experience, respectively, blinded to clinical and pathological information, tested and judged the samples. The accuracy rate between the three doctors and the GISTNet model was compared. Results: The GISTNet model yielded an AUC of 0.900 (95% CI: 0.827-0.973) in the test set. When the threshold value was 0.345, the sensitivity specificity, positive and negative predictive values of the GISTNet diagnosis model was 100%, 67%, 75% and 100%, respectively. The accuracy rate of the GISTNet diagnosis model was better than that of the GIST-risk model and the manual readings from two radiologists with 3 years and 9 years of work experience (83% vs. 75%, 60%, 65%), and was close to the manual reading of the radiologist with 19 years of work experience (83% vs. 80%). Conclusion: The deep learning algorithm based on contrast-enhanced CT has favorable and reliable diagnostic accuracy in distinguishing gastric GIST with a diameter ≤ 5 cm and other gastric SMT before operation.
Deep Learning ; Diagnosis, Differential ; Gastrointestinal Stromal Tumors/diagnostic imaging* ; Humans ; Retrospective Studies ; Stomach Neoplasms/diagnostic imaging* ; Tomography, X-Ray Computed

BACKGROUND: Texture analysis (TA) can quantify intra-tumor heterogeneity using standard medical images. The present study aimed to assess the application of positron emission tomography (PET) TA in the differential diagnosis of gastric cancer and gastric lymphoma. METHODS: The pre-treatment PET images of 79 patients (45 gastric cancer, 34 gastric lymphoma) between January 2013 and February 2018 were retrospectively reviewed. Standard uptake values (SUVs), first-order texture features, and second-order texture features of the grey-level co-occurrence matrix (GLCM) were analyzed. The differences in features among different groups were analyzed by the two-way Mann-Whitney test, and receiver operating characteristic (ROC) analysis was used to estimate the diagnostic efficacy. RESULTS: InertiaGLCM was significantly lower in gastric cancer than that in gastric lymphoma (4975.61 vs. 11,425.30, z = -3.238, P = 0.001), and it was found to be the most discriminating texture feature in differentiating gastric lymphoma and gastric cancer. The area under the curve (AUC) of inertiaGLCM was higher than the AUCs of SUVmax and SUVmean (0.714 vs. 0.649 and 0.666, respectively). SUVmax and SUVmean were significantly lower in low-grade gastric lymphoma than those in high grade gastric lymphoma (3.30 vs. 11.80, 2.40 vs. 7.50, z = -2.792 and -3.007, P = 0.005 and 0.003, respectively). SUVs and first-order grey-level intensity features were not significantly different between low-grade gastric lymphoma and gastric cancer. EntropyGLCM12 was significantly lower in low-grade gastric lymphoma than that in gastric cancer (6.95 vs. 9.14, z = -2.542, P = 0.011) and had an AUC of 0.770 in the ROC analysis of differentiating low-grade gastric lymphoma and gastric cancer. CONCLUSIONS InertiaGLCM and entropyGLCM were the most discriminating features in differentiating gastric lymphoma from gastric cancer and low-grade gastric lymphoma from gastric cancer, respectively. PET TA can improve the differential diagnosis of gastric neoplasms, especially in tumors with similar degrees of fluorodeoxyglucose uptake.
Fluorodeoxyglucose F18 ; Humans ; Lymphoma, Non-Hodgkin ; Positron Emission Tomography Computed Tomography ; Positron-Emission Tomography ; ROC Curve ; Radiopharmaceuticals ; Retrospective Studies ; Stomach Neoplasms/diagnostic imaging*

BACKGROUND: Gastric intestinal metaplasia (GIM) is generally considered to be the main mucosal background for the development of gastric adenocarcinomas. Using linked color imaging (LCI), we noticed that the color pattern in areas of GIM was purple mixed with white on the epithelium with signs of mist that were detected by the non-magnifying LCI observation. We have termed this endoscopic finding "Purple in Mist" (PIM). The aim of this study was to investigate whether PIM could be a useful optical sign for predicting GIM. METHODS: We prospectively evaluated consecutive patients undergoing endoscopy for various indications. The endoscopist used the LCI system to carefully observe the gastric antrum, body and angulus. When a PIM was identified in the surface layer, targeted biopsies were subsequently taken from this part. If the suspected area had no PIM on the surface, targeted biopsies were also taken. RESULTS: Sixty-three consecutive patients were included in this study. The prevalence of intestinal metaplasia (IM) was 29/63 (46%). In PIM-positive patients, the prevalence of IM was 23/26 (89%). Of these patients, 146 biopsy specimens were included in this study. For the diagnosis of IM, compared to histological assessment, the LCI finding had an accuracy of 91.1% (95%CI: 86.5%-95.7%), a sensitivity of 89.8% (95%CI: 81.3%-98.3%), a specificity of 91.8% (95%CI: 86.3%-97.2%), a positive predictive value of 84.6% (95%CI: 74.8%-94.4%), and a negative predictive value of 94.7% (95%CI: 90.1%-99.2%). CONCLUSIONS: A positive PIM finding in a suspicious lesion on LCI would complement LCI diagnosis of possible IM because of the positive predictive value of PIM. PIM could be a novel endoscopic marker for IM. TRIAL REGISTRATION ClinicalTrials.gov, No. NCT03092414; https://clinicaltrials.gov/ct2/show/NCT03092414?id=NCT03092414&rank=1.
Adult ; Aged ; Female ; Gastric Mucosa ; diagnostic imaging ; Gastroscopy ; methods ; Humans ; Male ; Metaplasia ; diagnostic imaging ; Middle Aged ; Prospective Studies ; Stomach Neoplasms ; diagnostic imaging