| Objective: To compare the tumor pathological characteristics and spectral CT quantitative parameters between patients with and without regional lymph node metastasis of gastric adenocarcinoma.To obtain quantitative parameters related to spectral CT iodine concentration(IC)values based on gastric cancer lesions and lymph nodes,and to explore their diagnostic efficacy in evaluating regional lymph node metastasis of gastric adenocarcinoma,aiming to find quantitative indicators with higher diagnostic efficacy.Methods: The clinical data and CT images of 55 patients with gastric adenocarcinoma diagnosed by pathology from June 2021 to June 2022 were collected retrospectively at Shengjing Hospital of China Medical University.Patients were divided into metastatic lymph node lesion group(32 cases)and non-metastatic lymph node lesion group(23 cases)according to whether there were metastatic lymph nodes in all the lymph nodes examined in the pathological results.Then lymph nodes were taken as the research object,and all lymph nodes were divided into the metastatic lymph node group(25 lymph nodes)and the non?metastatic lymph node group(27 lymph nodes)according to the nature of lymph nodes recorded in the pathological report.For early gastric cancer without significant thickening or bulging of the gastric wall,a region of interest(ROI)was delineated at the site where the enhancement of the lesion was most obvious.For advanced gastric cancer,the location of ROI was determined according to Borrmann typing,and the ROI was automatically matched to the iodine density map in arterial and venous phases.The IC values and normalized IC(n IC)values of gastric cancer lesions and lymph nodes in the arterial and venous phases(ICa and ICp,n ICa and n ICp)were obtained.The difference of IC and n IC values between arterial and venous phases(?IC and ? n IC)were calculated,and the arterial enhancement fraction(AEF,ratio of ICa and ICp of lymph nodes)was calculated.The chi-square test was used to compare the enumeration data of the two groups;Student′s t test or Mann?Whitney U test was used to compare the differences of quantitative parameters between the two groups.The parameters with statistical differences were analyzed by the receiver operating characteristic(ROC)curve to obtain the diagnostic efficacy of each parameter in evaluating lymph node metastasis of gastric cancer,and the Z test was used to compare the area under the curve(AUC)of each parameter.Results: 1.There were statistical differences in the differentiation degree,T stage and Borrmann classification between the metastatic lymph node lesion group and the non-metastatic lymph node lesion group(all P <0.05).And there was no statistically significant difference in gender,age and Lauren typing between the two groups(all P>0.05).2.The ICp,n ICp,?IC and ?n IC of the lymph node metastatic lesion group were higher than those of the lymph node non?metastatic lesion group(all P<0.05).The AUC were 0.738,0.746,0.811 and 0.821.3.There were significant differences in AUC between ICp and ?IC,?n IC(Z=2.41,3.29,P=0.016,0.001),and between n ICp and ?IC,?n IC(Z=2.10,3.09,P=0.036,0.002)in gastric cancer lesions.4.The short diameter,ICa,n ICa and AEF values of lymph nodes in the metastatic lymph node group were higher than those in the non?metastatic lymph node group(all P< 0.05).The AUC were 0.821,0.832,0.734 and 0.863.5.There were statistically significant differences in AUC between n ICa and ICa,AEF(Z=2.09,2.41,P=0.037,0.016)in lymph nodes.Conclusion: 1.According to Borrmann classification,the ROI delineation position of gastric adenocarcinoma lesions was determined to obtain IC value related indicators of spectral CT iodine concentration maps,which can be used for quantitative evaluation of gastric adenocarcinoma lesions hemodynamics.Among them,values?IC and ?n IC are more effective than other quantitative parameters in the diagnosis of lymph node metastasis.Detailed information such as the group,number of lymph nodes to be examined,length and diameter of lymph nodes were compared between the lymph nodes in the gastric cancer region on CT images and those submitted for pathological examination,and the lymph nodes with the longest length and diameter were included in the study to improve the accuracy of lymph node matching.On this basis,quantitative indexes of IC value of lymph nodes were obtained,among which AEF value had the highest diagnostic efficacy in the diagnosis of lymph node metastasis. |
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