Study On The Renal Tumors Using Diffusion-weighted Magnetic Resonance Imaging

Part Ⅰ Investigation of renal tumors by3.0T SS-EPI DWIObjective To analysis the apparent diffusion coefficient (ADC) value obtainedwith3.0T SS-EPI DWI in the differentiation of renal tumors with different pathologicalsubtypes. Materials and Methods30patients with renal tumors and15volunteerswith healthy kidneys underwent DWI were included in this study. All the tumors wereproved histopathologically. DWI were obtained with b values of0and600s/mm2，TheADC values in all groups were measured and analyzed statistically. correlations betweenthe ADC value、signal intensity of T2WI and the percentage change in signal intensityof dynamic contrast-enhanced were analyzed.Results The mean ADC value wassignificantly lower in CCRCC [(1.82±0.32)×103mm2/s] than in homolateral renalparenchyma [(2.31±0.22)×103mm2/s] and the normal renal parenchyma [(2.24±0.12)×103mm2/s](P＜0.001). The ADC value was also statistically differentbetween CCRCC and non-CCRCC.The correlations between the ADC value and the％SI change in the corticomedullary and nephrographic phases were positive. Conclusion3.0T SS-EPI DWI can provide useful information in the differentiation of renal tumorswith different pathological subtypes. The ADC value can reflect the hemodynamics ofrenal tumors to some extent. Part Ⅱ The application of rFOV DWI in the renal tumorsObjective To compare the ADC values and imaging qualities between rFOV DWIand SS-EPI DWI of renal tumors. Materials and Methods22patients with renal tumorsand14volunteers with healthy kidneys were included in this study. All the tumors wereproved histopathologically. DWI were obtained with b values of0and600s/mm2，TheADC values、subjective image quality scores of rFOV DWI and SS-EPI DWI in renaltumors、the homolateral renal parenchyma and the healthy kidney tissue were measuredand analyzed statistically. Results the artifact and image quality scores of rFOV DWIwere significantly better than SS-EPI DWI. The mean ADC value was significantly lowerin CCRCC than in homolateral renal parenchyma、the normal renal parenchyma and non-CCRCC (P＜0.05),The mean ADC value was significantly lower in rFOV DWIthan in SS-EPI DWI. Conclusion rFOV DWI has higher resolution、image quality scoresand the accuracy of ADC value measurement than SS-EPI DWI. Part Ⅲ Preliminary Study of Multi b-Value DWI in renaltumorsObjective Usefulness of pure molecular diffusion (Dslow)、perfusion-relateddiffusion (Dfast) and perfusion fraction (f) were calculated with biexponential model inevaluation of renal tumors.Materials and Methods28patients with renal tumors and13volunteers with healthy kidneys were included in this study. All the tumors were provedhistopathologically. DWI use8b values(0–1000s/mm2)，ADCtotwere derived bymonoexponential fitting of all the b values DWI data. Dslow、Dfastand f were calculated bybiexponential model. The parameters were compared between CCRCC、homolateral renalparenchyma、the normal renal parenchyma and non-CCRCC,and the receiver operatingcharacteristic analysis was performed. Results The DWI signal intensity of allhistological types which have the different b value-signal intensity cuve decreased withthe increasing of b value. Dslowhave higher accuracy in distinguishing CCRCC fromnon-CCRCC.Conclusion IVIM biexponential model of DWI imaging can providediffusion and perfusion simultaneously in kidney, The parameter Dslowmay help todistinguish renal tumors.