The Diagnostic Value Of Renal Clear Cell Carcinoma And Non-clear Cell Carcinoma With Dual-source CT Iodine Quantification

Objective Dual-source CT iodine quantification was used in the preoperative subtype and differentiation evaluation of renal cell carcinoma, to access its malignant degre preoperatively, and to guide the clinical treatment.Methods Eighty patients suspected renal masses were underwent with dual source CT cortical phase and nephrographic phase dual energy scan.45 pations with renal clear cell carcinoma pathologically confirmed,including clear cell renal cell carcinoma 30 cases,papillary renal cell carcinoma 12 cases,chromophobe renal cell carcinoma 3 cases, 17 well-moderately differentiated and 13 poorly differentiated neoplasms.The images wered analyed by one radiologist using two different methods,respectively.Method A observed the images through conventional approach, testing CT attenuation values of plain scan and that of weighted imaging fusion.Method B acquired iodine maps by in putting the data into Liver-VNC software, testing the VNC CT attenuation value.Overlay CT attenuation value and iodine concentration of the lesion after specifying the ROI.The CT attenuation value of virtual non-enhanced images compared to that of true non-enhanced images. The Overlay CT attenuation values of cortical phase and nephrographic phase compared to the conventionnal CT attenuation values. Iodine quantification and normalized idoine concentration(NIC) difference was studied between clear renal cell carcinomaand non-clear renal cell carcinoma and between well-moderately differentiated and poorly differentiated neoplasms. The diagnostic performances were evaluted using ROC analysis.Results The Overlay CT attenuation values of iodine maps were more than the conventionnal CT attenuation values of cortical phase and nephrographic phase,but there was no statistical difference((P>0.05)).The iodine quantification and NIC of clear cell carcinoma were more than that of non clear cell carcinoma in two phases. Statistical differences were found between two groups in two phases(P<0.05).According to the ROC,taking NIC0. 705 as threshold value in nephrographic phase, the sensitivity and specificity was 84.6 % and 76.7 %,respectively.The iodine quantification and NIC of well-moderately differentiated carcinoma were more than that of poorly differentiated in cortical phase and in nephrographic phase. Statistical differences were found between two groups in two phases(P<0.05).According to the ROC,taking NIC 0.735 as threshold value in nephrographic phase,the sensitivity and specificity was 87.4%,80.3%.Conclusions The iodine mapping of Dual-source CT provided us a more convenient method of evaluating enhance.Iodine quantification obtained from Dual-source CT can be used as new indexes for evaluation on the subtype and differentiation state of Renal Cell Carcinoma.