Study The Diagnostic Value Of Mulit-b-value DWI And The Quantitative Analysis Of DCE-MRI Combined Application In Ovarian Tumors

Objective To explore the value and feasibility of mulit-b-value diffusion weighted imaging(DWI),dynamic contrast enhanced-MR imaging(DCE-MRI)and both of them in the diagnosis of ovarian tumors.It was supposed to provide the noninvasive,repeatability and certain reference to identify benign or malignant ovarian tumors.Methods Collected the MRI data of 40 patients of ovarian tumor confirmed by surgery pathology,all of the patients had undergone conventional MR imaging,mulit-b-value diffusion weighted imaging and dynamic contrast enhanced-MR imaging on SIEMENS Verio 3.0 T scanner.The etiologic diagnosis acquired from the analysis of the imaging appearances which compared with histological results to obtain the sensitivity(Se),specificity(Sp),positive predictive value(PPV),negative predictive value(NPV)and accuracy.ADC values can be obtained by measuring the solid and cystic regions of tumor as well as the time-singnal intensity curve(TIC)and the quantitative parameters of Ktrans values,Kep values and Ve values measured the solid regions.Receiver operating characteristic analyses were performed to determine optimum thresholds for tumor qualitative diagnosis in that malignant tumors would be differentiated from benign tumors,and the Se,Sp,PPV and NPV were also calculated.Results(1)The mulit-b-value DWI unite DCE-MRI scan had a higher diagnostic efficiency of ovarian tumors than a single scan way,with sensitivity of 94.7%,specificity of 100%,positive predictive value of 100%,negative predictive value of 95.5%and accuracy of 97.5%.(2)There had no statistical differences in age between two groups(P>0.05);Statistically significant differences were noted in types of TIC curve in distinguishing between benign and malignant ovarian tumors(P<0.01).(3)There had significant statistical differences of ADC value,Ktrans values,Kep values and Ve values in solid regions between two groups as well as no statistical differences of ADC values in cystic regions.(4)The maximum Youden index was chosen to determine the optimum thresholds of all the parameters in ROC analyses to differentiate malignant from benign tumors.Statistical analysis showed a threshold value of 1.17×10-3mm2/s for ADC values to provide sensitivity,specificity,PPV,and NPV of 90.5%,89.5%,89.6%,and 90.4%.A threshold value of 0.093mim-1 for Ktrans values provided Se,Sp,PPV,and NPV of 85.7%,72.2%,75.5%and 83.5%.Conclusion(1)The best scan parameters of identify the benign and malignant tumor was b=1200s/mm2,and ADC values had certainly diagnostic value in the pathology of ovarian tumors.(2)The ktrans values had the most diagnostic value of benign and malignant ovarian tumors in the quantitative analysis of DCE-MRI.(3)The application of mulit-b-value DWI combined with DCE-MRI improved the diagnostic accuracy of ovarian tumors before operation.