Application Of 3.0T MR Diffusion Weighted Imaging In The Diagnosis And Differential Diagnosis Of Renal Substance Tumor

Objective:To study the diagnostic utility of Magnetic Resonance Diffusion weighted imaging (MR DWI)in differentiating renal tumor. To evaluate the identified value of apparent diffusion coefficient(ADC) in differentiating benign from the malignant renal tumors,differentiating various pathologic grades of renal clear cell carcinoma,and analyzing the effect the renal tumor had on peritumoral renal parenchyma.Materials and Methods:35 patients and 5 healthy volunteers underwent 3.0T conventional MRI scanning and diffusion weighted imaging scanning before surgical operation. All the patients were Surgical and pathological diagnosed.Among the patients were 16 males and 19 females (Age:21-72, Averaging age:48).5 volunteers included 3 males and 2 females(Age:22-41, Averaging age:31). DWI were obtained with b values of 0,400and 600 s/mm2.By two experienced radiologists blinded reading and analyzed data.Using workSyngo workstation FoncTool software for DWI data post-processing.ROI(region of interest)was as far as possible big and at the same size.ROI placed in the essence of the tumor, peritumoral renal parenchyma and the contralateral normal kidney area.By using intraclass correlation coefficient (ICC) and the nonparametric test in the statistical software SPSS 19.0 to analyze and statistics the consistency of the two ADC values and the data of each group.Result:35 lesions included 12 benign lesions and 23 malignant lesions. Benign lesions included 10 angiomyolipomas and 2 acidophilic cell adenoma. Malignant lesions included 21 Renal clear cell carcinoma and 2 chromophobe cell tumor.21 renal clear cell carcinoma 15 cases for grade 11,5 cases for grade Ⅲ,1 case for grade IV.1、the average ADC values of benign tumors (0.93±0.12×10-3mm2/s) was lower than that of malignant tumors of the average ADC values (1.72±0.09×10-3mm2/s).The difference was statistically significant, the ADC values of cases groups were lower than that of renal parenchyma in control group (2.08 ± 0.02×10-3mm2/s).ROC curve was drawn by ADC values of benign and malignant tumor. The area under the curve was 0.877.When put 1.27×10-3mm2/s as threshold, the sensitivity was 78.3% and specificity was 75%.2、The average ADC values of high level group tumors of renal clear cell cancer (1.46±0.17×10-3mm2/s) was lower than the average ADC value of low level group tumors (1.94±0.08×10-3mm2/s).ROC curve was drawn by ADC values of the different grade group tumors.The area under the ROC curve was 0.808.When put 1.23×10-3mm2/s as threshold, the sensitivity was 90.5% and specificity was 71.4%.3、tumor and peritumoral renal parenchyma and the contralateral renal parenchyma groups:Comparison among groups:1)ADC values of Benign tumor (0.93±0.12×10-3mm2/s) was lower than that of normal contralateral renal parenchyma (2.12±0.05×10-3mm2/s) and that of the peritumoral renal parenchyma (2.10±0.03×10-3mm2/s).The difference had statistically significant.2)The difference of ADC values between benign peritumoral renal parenchyma and contralateral normal renal parenchyma had no statistically significant.3)ADC values of malignant tumor (1.72±0.09×10-3mm2/s) was lower than that of normal contralateral renal parenchyma (2.11±0.03×10-3mm2/s).and that of the peritumoral renal parenchyma (2.01±0.03×10-3mm2/s). The difference had statistically significant.4)ADC values of malignant peritumoral renal parenchyma was lower than that of normal contralateral renal parenchyma.The difference had statistically significant. Comparison between groups:5)When used Mann-Whitney U test to compare the difference of ADC values between benign peritumoral renal parenchyma and malignant peritumoral renal parenchyma,there had no statistically significant.The same results can be found in benign contralateral renal parenchyma and malignant contralateral renal parenchyma.6)Compared benign and malignant contralateral renal parenchyma to healthy volunteers by Mann-Whitney U test,the difference of ADC values had no statistically significant.Conclusion:Magnetic Resonance Diffusion weighted imaging (MR DWI)possess the ability of qualitative diagnosis in renal tumor.Value of apparent diffusion coefficient(ADC) can differentiate between benign from the malignant renal tumors,differentiating among various pathologic grades of renal tumors,and analyze the effect the malignant renal tumor had on peritumoral renal parenchyma...