Clinical Study On Anatomy Morphology And Functional Of Medical Imaging In Preoperative Staging And Prognosis Of Gastric Cancer

Part One Comparatlive study on Image Morphology of preoperative T staging of gastric CancerGastric cancer has been a high incidence and mortality of malignant tumors in the world,which is a serious threat to human life and health,especially in Northeast Asia,the incidence is the highest.In 2018,the incidence of gastric cancer ranked fifth,behind lung,breast,colorectal and prostate cancer,and the mortality rate ranked third,after lung cancer and colorectal cancer according to the World Health Organization.In Cbina,the incidence of malignant tumors ranks third,accounting for 10.6%,and the mortality rate ranks second,accounting for 13.6%.At present,there are many individu-al schemes for the treatment of gastric cancer,and surgery is still the most effective treatment for gastric cancer.Preoperative accurate TNM staging by imaging means can provide the most appropriate treatment for the clinic,improve the prognosis after treatment,and prolong the life of patients.In recent years,Endoscopic ultrasonography(EUS)and computed tomography(CT)are commonly used for preoperative staging of gastric cancer.Magnetic reson-ance imaging(MRI)has high soft tissue resolution and no radiation.With the rapid development of fast imaging technology,clinical application of magnetic resonance imaging in gastric tumors has become the focus of attention.In this study,it is rare to report that each patient with gastric cancer completed magnetic resonance imaging,computed tomography,ultrasonic gastroscopy for comparison of the three examina-tions.Objective:To provide accurate diagnostic basis for accurate treatment,the accuracy of preoperative staging of gastric cancer by magnetic resonance imaging(MRI),computed tomography(CT)and endoscopic ultrasonography(EUS)was compared and studied.In addition,the factors affecting the accuracy of magnetic resonance imaging,computed tomography and ultrasonic gastroscopy staging are analyzed,so as to find a reasonable examination scheme for preoperative staging of gastric cancer can solve the clinical confusion and reduce the burden of patients.Methods:This study was reviewed and approved by the ethics committee of our hospital,and all the subjects signed informed consent before they were examined.126 patients with gastric cancer confirmed by endoscopic gastric biopsy were examined by ultrasonography,computed tomography and magnetic resonance imaging.After exclusion criteria,96 patients were finally included in the study.Ultrasonic gastroscopy,computed tomography and magnetic resonance imaging were performed by professional physicians or technicians.Two abdominal radiologists with more than 18 years of experience diagnosed and reconstructed image data on the workstation for patients with gastric cancer.The reference criteria for staging diagnosis are the staging signs mentioned in the eighth edition of AJCC,s TNM staging guidelines for gastric cancer and the self-made MRI staging signs.The consistency of MRI,CT,EUS staging results with pathological results was tested by Kappa test,and the statistical method SPSS22.0 software was used.The accuracy of MRI,CT and EUS in different pathological stages was tested by chi-square test.Chi-square test was used to analyze the influencing factors of staging accuracy of MRI,CT and EUS.Results:1.Clinicopathological features of subjects included in MRI,CT and EUS imaging examinationA total of 96 patients,69 males and 27 females,with an average age of 60 years,were enrolled in the study.There were 34 cases of gastric antrum,29 cases of gastric fundus and 33 cases of gastric body.There were 2 cases of high differentiation,41 cases of middle differentiation and 53 cases of low differentiation.There were 66 cases of adenocarcinoma,21 cases of signet ring cell carcinoma,8 cases of mucinous adenocarcinoma and 1 case of tubular adenocarcinoma.There were 19 cases in stage T1,15 cases in stage T2,10 cases in stage T3,46 cases in stage T4a and 6 cases in stage T4b.2.Accuracy and comparison of three imaging methods in stagingIn T staging of gastric cancer,the overall accuracy of EUS was 51.04%,the overall accuracy of CT was 70.84%,and the overall accuracy of MRI was 83.33%.Compared with pathological T stage,Kappa values of EUS,CT and MRI were 0.3,0.57 and 0.77,respectively.Magnetic resonance imaging(MRI)is of high diagnostic value.The accuracy of EUS,CT and MRI in T1 and T4a was statistically significant.3.Factors affecting the accuracy of staging of three imaging methodsThe accuracy of CT staging was different in different sites(p<0.05),MRI staging accuracy was different in different histological classification(p<0.05),CT,EUS staging accuracy was different in different pathological T staging(p<0.05);The staging accuracy of MRI and CT in upper gastric cancer was 86.2%and 89.66%respectively.The accuracy of MRI staging in middle and lower gastric cancer was significantly higher than that of CT and EUS.The accuracy of MRI was 78.79%and 85.29%respectively.The accuracy of CT and EUS were 63.63%and 61.76%and 48.48%and 55.88%respectively.The higher the degree of differentiation is,the higher the accuracy of MRI is.The accuracy of MRI staging was 89.47%,and the accuracy of MRI was higher than that of CT and EUS in different differentiation groups.The accuracy of MRI in T1 stage was 73.70%,which was significantly better than that of CT and EUS.In the advanced stage,the accuracy of MRI and CT Is almost the same as that of T4a and T4b,up to more than 90%.The accuracy of MRI in staging of mucinous adenocarcinoma was as high as 100%,which was higher than that of other histological classification.Conclusions:The accuracy of EUS in the diagnosis of T1 and T2 gastric cancer was low,and there was a significant overestimation of staging,and the accuracy of T3 and T4a staging was increased.The accuracy of CT imaging in T1 and T2 of early gastric cancer was not high.the accuracy of T4a and T4b was higher than 90%and 100%respectively.The accuracy of MRI imaging was 73.68%and 66.67%in T1 and T 2 stages of early gastric cancer,which was significantly better than that of CT and EUS.The accuracy of stage T3,T4a and T4B in advanced gastric cancer was 90%,89.10%and 100%respectively.The accuracy of MRI in upper,middle and lower gastric cancer was significantly better than that of CT and EUS,which were 86.21%,78.79%and 85.29%,respectively.The accuracy of MRI in different differentiation degree staging was obviously better than that of CT and EUS;.MRI was sensitive to the staging of different histological types of gastric cancer,the accuracy of staging of mucinous adenocarcinoma and signet ring cell carcinoma was 100%and 71.40%respectively,which were significantly better than those of CT and EUS.Part Two Quantitative study on preoperative staging and prognosis of gastric cancer by voxel incoherent motion diffusion weighted imagingFunctional magnetic resonance imaging(fMRI)has been used in clinic for more than 20 years,and its clinical value has been recognized.Diffusion-weighted imaging(DWI)is a single exponential model functional imaging,which can only provide overall water molecular diffusion information,and there is only one imaging biomar-ker of ADC.The diffusion weighted imaging of incoherent motion in voxel is a functional imaging of double exponential model,which can obtain the simple diffuse-ion information and perfusion information of tumor,and three imaging biomarkers can be obtained for quantitative study.In recent years,it has been used to study abdo-minal organs,there are few reports on the application of gastric tumors.Objective:The value of IVIM quantitative study in preoperative T,N staging and differentiation of gastric carcinoma.To study the quantitative value of IVIM in T,N stage and differentiation of gastric cancer before operation.Diagnostic threshold of IVIM parameters to determine whether there is invasion of serous structure,lymphatic metastasis and degree of differentiation.To study the relationship between IVIM parameters and prognostic factors of gastric cancer,including HER-2 and Ki67.Methods:This study was reviewed and approved by the ethics committee of our hospital,and all the subjects signed informed consent before they were examined.One hundred and thirty patients with gastric cancer were confirmed by endoscopic biopsy and IVIM sequence of MRI was completed.After excluding the factors that could not be selected,98 patients were finally enrolled in the study.The IVIM sequence data were imported into the software for post-processing of tumor ROI region,and the parameters f value,D value and D*value were generated.The IVIM parameters f,D and D*of different T and N stages were analyzed by one-way ANOVA.The IVIM parameters of serosa invasion,lymphatic metastasis,differentiation degree and HER2 positive expression were analyzed by ROC and t test.Correlation Analysis between IVIM parameters f,D,D*and Ki67 protein expression.Results:1.A total of 98 patients,65 males and 33 females,with an average age of 61.9 years,were enrolled in the study.There were 30 moderately and highly differentiated and 68 poorly differentiated.There were 14 patients in stage T1,14 in stage T2,10 in stage T3 and 60 in stage T4a+b.There were 37 patients in stage N0,19 in stage N1,18 in stage N2 and 24 in stage N3.There were 44 patients with human epidermal growth factor receptor(HER-2)score of 0,19 patients with score 1,15 patients with score 2 and 7 patients with score 3.Ki67 immunoprotein marker were performed in 85 lesions.2.The D value of IVIM parameter had statistical significance in different pathological T stages of gastric cancer.The D value of stage T4 was significantly different from that of stage T2,stage T3 and stage T4.The higher the pathological T stage,the smaller the D value.The parameter D value has statistical significance in judging whether the serosa is infringed or not,and its diagnostic threshold is 1.1074�10-3mm2/s.The f value of IVIM parameter was significantly different in different pathological N stages of gastric cancer.The parameter D value of IVIM was statistically significant in judging lymph node metastasis,and its diagnostic threshold was 1.1739�10-3 mm2/s.3.The differential differentiation degree of IVIM parameter D*value was statistically significant.the D*value of low differentiation parameter was higher than that of middle and high differentiation group,and its diagnostic threshold is 1.516�10-2mm/s.The D*value of IVIM parameter was statistically significant in different HER-2 scoring grades.The lower the scoring level was,the higher the D*value was.There was a significant negative correlation between the D value of IVIM parameter and the percentage of Ki67 protein expression.Conclusions:The D value of IVIM parameter can be used to quantitatively analyze the preoperative T staging grade of gastric cancer.D value has clinical value in differential diagnosis of whether gastric cancer invades serosa or not.when D value is less than 1.1074�10-3mm2/s,it can be diagnosed as invasion of serosa,the accuracy rate is 85.71%.The f values of different N stages were also different.Lymphatic metastasis can be diagnosed when D value is less than 1.1739�10-3mm2/s.The D*value of different differentiation degree is different.the lower the differentiation is,the higher the D*value is.When D*>1.516�10-2mm2/s,it can be used to diagnose gastric cancer,which belongs to poorly differentiated gastric cancer.The D*values of different HER-2 grades were different,and the D*values of HER-2 positive lesions were even lower.HER-2 positive can be diagnosed when D*value is less than 1.516�10-2mm2/s.D value was negatively correlated with Ki67 expression.Quantitative staging with IVIM parameters can be an alternative method for preoperative staging of gastric cancer.