| Sectionâ… Application of diffusion weighted imaging in diagnosis of renal massesObjectiveMagnetic resonance diffusion weighted imaging (DWI) is being considered theunique method available to measure molecular diffusion of water in vivo. This study isto evaluate the feasibility of DWI in kidney deseases, to choose the best optimal bvalue for detecting renal leisions, to determine whether the ADC value havesignificant discrepancies among the normal kidney, the benign lesions and themalignant lesions in kidney, to determine the diagnostic value of DWI indifferentiation of renal lesions.Materials and methodSeventy-six cases including 61 cases renal masses and 15 cases normalvolunteers were divided into three groups: the first group included 32 cases ofmalignant lesions, whose age ranged from 17 to 74, mean age was 56.4years. Thesecond group included 29 cases of benign lesions whose age ranged from 26 to74,mean age was 52.4 years. The third group included 15 cases of normal kidneywhose age ranged from 22 to 67, mean age was 42 years. Thirty-two cases ofmalignant lesions and 4 cases of benign lesions (3 cases of angioleiomyolipoma and1 case of complexitious cyst) were proved by operation. Twenty-five cases of benignlesions (1 case of angioleiomyolipoma and 24 cases of simple cysts) were proved byclinical data and other imageology examinations. All cases were proceeded DWI and conventional MRI (including axial T2WI). The raw data of DWI were transmitted tothe workstation to generate the corresponding maps of ADC. With accordance toaxial T2WI, the ADC values of ROI within both the renal leisions and the the normalrenal parenchyma(the boundary of cortex and medulla at the level of renal hilum)were measured. The ADC values with different b values of the renal leisions and thenormal renal parenchyma were proved to be a gaussian distribution with softwareSSPS12.0. And the ADC values with different b values of interclass and intraclass ofthe normal renal parenchyma group, the benign lesions group, and the malignantlesions group were ANOVA for statistical analysis. A p value less than 0.05 wasconsidered significant difference.ResultThe ADC values with different b values of interclass and intraclass among thenormal renal parenchyma group, the benign lesions group and malignant lesionsgroup had statistical difference. The ADC values of the malignant leisions groupwere lower than that of the normal renal parenchyma group, and the ADC values ofthe benign lesions group was higher than the normal renal parenchyma.On the basis of imaging quality of DWI and the accuracy ADC values, the mostoptimal b value of DWI for renal leisions was 500 sec/mm2. The mean ADC value innormal renal parenchyma was (2.4670±0.3846)×10-3 mm2/s, the mean ADCvalue in renal carcinoma was (1.7424±0.2759)×10-3 mm2/s, the mean ADC valuein simple cysts was (3.5360±0.5293)×10-3 mm2/s, the mean ADC value inangioleiomyolipoma was (1.9387±0.1785)×mm2/s, the mean ADC value incomplexitious cyst was (1.6421±0.0721)×10-3 s mm2/s.Conclusion1. With b value of DWI increasing, the SNR (signal to noise ratio) value decreased.The most optimal b value of DWI for renal leisions was 500 sec/mm2.2. DWI could provid fuctional information while the conventional MRI could not. The ADC values of interclass and intraclass had statistical difference of among thenormal renal parenchyma, the benign lesions, and the malignant lesions. The analysisof DWI and the measurement of ADC value could be applied to differentiate the thenormal renal parenchyma, the benign lesions and the malignant leision.Sectionâ…¡Comparison of diagnostic value between the conventional and MRI the combination using of DWI and MRI in characterization of renal leisionsObjectiveMagnetic resonance imaging has many advantages as such multi-planar,multi-parameter, multi-sequence imaging, which can display the marpharlogy of renalleisions in detail and the relationship with surrounding tissue. This present study is tocompare the diagnostic value between the conventional MRI and the combinationusing of DWI and MR/in characterization of renal leisions.Materials and methodsnSixty-one cases were divided into two groups: the first group included 32 casesof malignant lesions, whose age ranged from 17 to 74 years, with mean age of56.4years. The second group included 29 cases of benign lesions, whose age rangedfrom 26 to 74 years, with mean age of 52.4years. All the cases were undermentconventional MRI (including axial T1WI, T2WI, and fat-suppressed T1WI, T2WI) andDWI.Double-blind method was performed to analyze the manifestations of DWI,ADC map, ADC value, and the degree of accuracy in diagnosis of renal leisions bythe combination of DWI and MRI. Applying double-blind method to analyze themanifestations of the conventional MRI and the degree of accuracy in diagnosis ofrenal leisions. Accuracies in diagnosis of renal leisions were compared between theconventional MRI and the combination using of DWI and MRI. ResultWith the conventional MRI in renal leisions, diagnostic accuracy of malignantlesions and benign lesions were 93.8% and 97.8% respectively, the degree ofaccuracy of the TNM staging for (Renal cell carcinoma, RCC)RCC were stage-â… 80%, stage-â…¡84.2%, stage-â…¢100%, and stage-â…£100% respectively.With the combination using of DWI and MRI in renal leisions, the degree ofdiagnosis of accuracy in malignant lesions and benign lesions were 96.9% and 100%respectively.Conclusion1. The RCC could be staged precisely by conventional MRI.2. The combination using of DWI and MRI could improve the accuracy incharacterization of renal lesions and the staging of RCC.Novel ideas in the present studyThis study analysed the value of DWI in dignosis and differentiating of renalleisions, and choose the most optimal b value for renal leisions. The study alsosuggersted that the ADC value had significant statistical difference among the normalkidney, the benign lesions and malignant lesions, and DWI could provide us manyvaluable functional information for dignosis and differential diagnosis. Theconventional MRI can demonstnase the morphology of renal leisions in detail andthe relationship with surrounding tissue, and it could staging RCC precisely.
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