Application Of 3D-dynamic Contrast-enhanced MRI In The Evaluation Of Vascular Architecture Of Pulmonary Solid Solitary Nodules

Objective: Study on the value of quantitative parameters on Dynamic Contrast Enhanced MRI in the assessment of vascular architecture of solitary pulmonary nodules.Method:The data of 32 patients with benign and malignant pulmonary nodules confirmed by surgery in the First Affiliated Hospital of Guangxi Medical University were collected.Conventional MRI and DCE-MRI scans of chest were performed with German Siemens 3.0TMR scanner before operation in all patients,and fixed them with 8-channel body coil.The original data were manually imported into the image perfusion processing software Tissu4 D to obtain the final mean data and time-signal(TIC)curves of the Ktrans,Kep and Ve values of the pulmonary solid solitary nodules in the line of multi-parameter measurement.All patients were labeled with CD31,VEGF and SMA immunohistochemical markers,and the parameters of vascular architecture were obtained by image analysis software ImageJ.The independent sample T test was used to compare the differences of DCE-MRI quantitative parameters between benign and malignant nodules.The differences of different quantitativeparameters and pathological stages of DCE-MRI were evaluated by single factor ANOVA test and Kruskal-Wilk H test Statistical method;Pearson correlation analysis was used to find the correlation between the quantitative parameters of DCE-MRI and the parameters of each vessel.Analyzing the diagnostic efficiency of quantitative parameters of DCE-MRI depends on drawing the ROC curve,calculating the area(AUC),under the curve and finding the optimal threshold value which is helpful to differential diagnosis of diseases by suspending the Joden index.Results: All the patients in the group were divided into two groups according to pathological results: benign group and malignant group: benign group and malignant group,the latter were divided into high,middle,low differentiation group and groups T1,T2,T3,T4 according to the degree of differentiation and pathological stages.There was significant difference in Ktrans and Ve values between benign and malignant pulmonary nodules(P<0.05).The Ktrans values increased gradually with the degree of differentiation,and were statistically significant(P<0.05).Compared with different pathological staging groups,the value of Ktrans,Kep,Ve increased gradually with the increase of stage,and all of them had statistical significance(P<0.05).There was a correlation between Ktrans Kep and microvessel parameters(CD31-MVD,VEGF,MPI)(P <0.05).There was a correlation between Ve and microvessel parameters(CD31-MVD,VEGF)(P <0.05),but there was no correlation with the vessel maturity parameters MPI.The ROC curve analysis showed that the areas under the ROC of Ktrans,Kep and Ve values for the diagnosis of malignant pulmonary nodules were 0.922,0.521 and 0.911,and the threshold value could be used as the critical value for differential diagnosis.Conclusion: 1.Dynamic contrast-enhanced MRI has certain diagnostic value in evaluating the pathological grade and differentiation of pulmonary nodules,Among them,Ktrans value has diagnostic value in different degree of differentiation,and has significant difference.The values of Ktrans,Kep and Ve were of diagnostic value in different pathological grades,and the difference of Ve,Kep value was more significant than that of Ktrans value.2.Quantitative permeability parameters of DCE-MRI can indirectly quantify tumor microvessel production,blood perfusion characteristics,and reflect tumor microvessel maturity,further,dynamic and repeated observations were used to evaluate the vascular architecture of solid solitary pulmonary nodules.3.The SMA-MVD and MPI values of vascular architecture parameters can be quantificationally reflected in mature and immature vessels in benign and malignant nodules;whether VEGF and CD31-MVD can evaluate the vascular architecture of solid solitary pulmonary nodules with different properties needs to be further studied.4.Dynamic contrast-enhanced MRI can be used as an effective auxiliary method for differential diagnosis of pulmonary nodules of different nature,after drawing the ROC curve,we can find the critical value of differential diagnosis,and it has high sensitivity and specificity,which has certain guiding significance for its clinical treatment and prognosis evaluation.