Background：Diffusion weighted imaging （DWI）,with the applying of intravoxel incoherent motion model,has showed promising results in obtaining additional information about microperfusion and tubular flow associated ...Background：Diffusion weighted imaging （DWI）,with the applying of intravoxel incoherent motion model,has showed promising results in obtaining additional information about microperfusion and tubular flow associated with morphologic changes in chronic kidney diseases.The study aims to evaluate the potential of T2-weighted signal intensity （SI） and DWI with mono-and bi-exponential models to reflect the serial changes on cisplatin （CP） induced rat renal fibrosis models.Methods：Magnetic resonance exams were performed prior to and 2nd day,4th day,6th day,8th day,2nd week,3rd week and 4th week after CP injection at a 3.0T with an animal coil.Besides T2-weighted images （T2WI）,DWI of 13 b values from 0 to 1500 s/mm^2 was acquired.Apparent diffusion coefficient （ADC）,fluid fraction f,pure diffusivity D and pseudodiffusivity D＊ values were calculated.The regions of interest were placed on cortex （CO）,outer stripe of the outer medulla （OM） and inner stripe of the outer medulla （OM）,parameters were measured and compared among different time points.Five rats were scarified at each time point for pathological examination.Results：OM revealed remarkable hyperintense and broadened before it became an obscure thread,while CO demonstrated moderate hyperintense and IM didn＇t show significant change on T2WI.On all three stripes,ADC values decreased firstly then kept increasing since the 4th day;f values decreased on all stripes; D values had a tendency to increase with fluctuations but the changes didn＇t achieve statistical significance; D＊ values increased at the 2nd day then tended to be steady thereafter.Pathological findings revealed tubules epitheliums swelling followed by inflammation cells infiltration,interstitial fibrosis was observed since the 2nd week.Conclusions：All of T2-weighted SI,ADC,and biexponential models parameters vary during fibrotic process; biexponential model is superior to monoexponential model in separating changes of microperfusion together with tubular flow from pure diffusion.展开更多
基金This work was supported by grant from Chinese Nature Science Foundation （No. 81171316）.
文摘Background：Diffusion weighted imaging （DWI）,with the applying of intravoxel incoherent motion model,has showed promising results in obtaining additional information about microperfusion and tubular flow associated with morphologic changes in chronic kidney diseases.The study aims to evaluate the potential of T2-weighted signal intensity （SI） and DWI with mono-and bi-exponential models to reflect the serial changes on cisplatin （CP） induced rat renal fibrosis models.Methods：Magnetic resonance exams were performed prior to and 2nd day,4th day,6th day,8th day,2nd week,3rd week and 4th week after CP injection at a 3.0T with an animal coil.Besides T2-weighted images （T2WI）,DWI of 13 b values from 0 to 1500 s/mm^2 was acquired.Apparent diffusion coefficient （ADC）,fluid fraction f,pure diffusivity D and pseudodiffusivity D＊ values were calculated.The regions of interest were placed on cortex （CO）,outer stripe of the outer medulla （OM） and inner stripe of the outer medulla （OM）,parameters were measured and compared among different time points.Five rats were scarified at each time point for pathological examination.Results：OM revealed remarkable hyperintense and broadened before it became an obscure thread,while CO demonstrated moderate hyperintense and IM didn＇t show significant change on T2WI.On all three stripes,ADC values decreased firstly then kept increasing since the 4th day;f values decreased on all stripes; D values had a tendency to increase with fluctuations but the changes didn＇t achieve statistical significance; D＊ values increased at the 2nd day then tended to be steady thereafter.Pathological findings revealed tubules epitheliums swelling followed by inflammation cells infiltration,interstitial fibrosis was observed since the 2nd week.Conclusions：All of T2-weighted SI,ADC,and biexponential models parameters vary during fibrotic process; biexponential model is superior to monoexponential model in separating changes of microperfusion together with tubular flow from pure diffusion.
