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Monitoring the progression of renal fibrosis by T2-weighted signal intensity and diffusion weighted magnetic resonance imaging in cisplatin induced rat models.

Wu HH, Jia HR, Zhang Y, Liu L, Xu DB, Sun HR - Chin. Med. J. (2015)

Bottom Line: 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 4 th day; f values decreased on all stripes; D values had a tendency to increase with fluctuations but the changes didn't achieve statistical significance; DFNx01 values increased at the 2 nd day then tended to be steady thereafter.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Tianjin Medical University Hospital, Tianjin, China.

ABSTRACT

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 2 nd day, 4 th day, 6 th day, 8 th day, 2 nd week, 3 rd week and 4 th 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 DFNx01 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 4 th day; f values decreased on all stripes; D values had a tendency to increase with fluctuations but the changes didn't achieve statistical significance; DFNx01 values increased at the 2 nd day then tended to be steady thereafter. Pathological findings revealed tubules epitheliums swelling followed by inflammation cells infiltration, interstitial fibrosis was observed since the 2 nd 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.

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Serial changes of mono-exponential and biexponential models parameters on renal parenchyma in rats prior to and at different time points after CP administration. (a) Serial changes of ADC value. ADC values decreased firstly then kept increasing since the 4th day; (b) Serial changes of f fractions. The f values of all three stripes were below the normal level after CP injection, and the changes on OM were more remarkable; (c) Serial changes of D values. D values had a tendency to increase with downward fluctuation; (d) Serial changes of D* values. D* values of CO, OM and IM stripes increased at the 2nd day, and then tended to be steady thereafter till the 3rd week. CO: Renal cortex; CP: Cisplatin; ADC: Apparent diffusion coefficient; OM: Outer stripe of the outer medulla; IM: Inner stripe of the outer medulla. *P < 0.05 compared with normal kidney; †P < 0.05 compared with the 2nd day after kidney CP administration; ‡P < 0.05 compared with the 4th day after kidney CP administration; §P < 0.05 compared with the 6th day after kidney CP administration; //P < 0.05 compared with the 8th day after kidney CP administration; ¶P < 0.05 compared with the 2nd week after kidney CP administration; **P < 0.05 compared with the 3nd week after kidney CP administration.
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Figure 3: Serial changes of mono-exponential and biexponential models parameters on renal parenchyma in rats prior to and at different time points after CP administration. (a) Serial changes of ADC value. ADC values decreased firstly then kept increasing since the 4th day; (b) Serial changes of f fractions. The f values of all three stripes were below the normal level after CP injection, and the changes on OM were more remarkable; (c) Serial changes of D values. D values had a tendency to increase with downward fluctuation; (d) Serial changes of D* values. D* values of CO, OM and IM stripes increased at the 2nd day, and then tended to be steady thereafter till the 3rd week. CO: Renal cortex; CP: Cisplatin; ADC: Apparent diffusion coefficient; OM: Outer stripe of the outer medulla; IM: Inner stripe of the outer medulla. *P < 0.05 compared with normal kidney; †P < 0.05 compared with the 2nd day after kidney CP administration; ‡P < 0.05 compared with the 4th day after kidney CP administration; §P < 0.05 compared with the 6th day after kidney CP administration; //P < 0.05 compared with the 8th day after kidney CP administration; ¶P < 0.05 compared with the 2nd week after kidney CP administration; **P < 0.05 compared with the 3nd week after kidney CP administration.

Mentions: Mean ADC values of all the CO, OM and IM decreased firstly and then kept increasing since the 4th day. The mean ADC values of OM were higher than normal subject (4.38 ± 0.63 × 10−4 mm2/s vs. 4.91 ± 0.56 × 10−4 mm2/s, P < 0.05), while the ADC values of CO were similar to normal level (5.7 ± 0.79 × 10−4 mm2/s, P > 0.05) since the 6th day. The changes of ADC values for OM and CO tended to be stable during the 6th and 4th week (P > 0.05). In IM, excepted for the 4th week (4.33 ± 0.93 × 10−4 mm2/s, P = 0.07), mean ADC values were significant lower than normal subjects (5.23 ± 1.05 × 10−4 mm2/s) at all time points (P < 0.05) [Figure 3a].


Monitoring the progression of renal fibrosis by T2-weighted signal intensity and diffusion weighted magnetic resonance imaging in cisplatin induced rat models.

Wu HH, Jia HR, Zhang Y, Liu L, Xu DB, Sun HR - Chin. Med. J. (2015)

Serial changes of mono-exponential and biexponential models parameters on renal parenchyma in rats prior to and at different time points after CP administration. (a) Serial changes of ADC value. ADC values decreased firstly then kept increasing since the 4th day; (b) Serial changes of f fractions. The f values of all three stripes were below the normal level after CP injection, and the changes on OM were more remarkable; (c) Serial changes of D values. D values had a tendency to increase with downward fluctuation; (d) Serial changes of D* values. D* values of CO, OM and IM stripes increased at the 2nd day, and then tended to be steady thereafter till the 3rd week. CO: Renal cortex; CP: Cisplatin; ADC: Apparent diffusion coefficient; OM: Outer stripe of the outer medulla; IM: Inner stripe of the outer medulla. *P < 0.05 compared with normal kidney; †P < 0.05 compared with the 2nd day after kidney CP administration; ‡P < 0.05 compared with the 4th day after kidney CP administration; §P < 0.05 compared with the 6th day after kidney CP administration; //P < 0.05 compared with the 8th day after kidney CP administration; ¶P < 0.05 compared with the 2nd week after kidney CP administration; **P < 0.05 compared with the 3nd week after kidney CP administration.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
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getmorefigures.php?uid=PMC4834773&req=5

Figure 3: Serial changes of mono-exponential and biexponential models parameters on renal parenchyma in rats prior to and at different time points after CP administration. (a) Serial changes of ADC value. ADC values decreased firstly then kept increasing since the 4th day; (b) Serial changes of f fractions. The f values of all three stripes were below the normal level after CP injection, and the changes on OM were more remarkable; (c) Serial changes of D values. D values had a tendency to increase with downward fluctuation; (d) Serial changes of D* values. D* values of CO, OM and IM stripes increased at the 2nd day, and then tended to be steady thereafter till the 3rd week. CO: Renal cortex; CP: Cisplatin; ADC: Apparent diffusion coefficient; OM: Outer stripe of the outer medulla; IM: Inner stripe of the outer medulla. *P < 0.05 compared with normal kidney; †P < 0.05 compared with the 2nd day after kidney CP administration; ‡P < 0.05 compared with the 4th day after kidney CP administration; §P < 0.05 compared with the 6th day after kidney CP administration; //P < 0.05 compared with the 8th day after kidney CP administration; ¶P < 0.05 compared with the 2nd week after kidney CP administration; **P < 0.05 compared with the 3nd week after kidney CP administration.
Mentions: Mean ADC values of all the CO, OM and IM decreased firstly and then kept increasing since the 4th day. The mean ADC values of OM were higher than normal subject (4.38 ± 0.63 × 10−4 mm2/s vs. 4.91 ± 0.56 × 10−4 mm2/s, P < 0.05), while the ADC values of CO were similar to normal level (5.7 ± 0.79 × 10−4 mm2/s, P > 0.05) since the 6th day. The changes of ADC values for OM and CO tended to be stable during the 6th and 4th week (P > 0.05). In IM, excepted for the 4th week (4.33 ± 0.93 × 10−4 mm2/s, P = 0.07), mean ADC values were significant lower than normal subjects (5.23 ± 1.05 × 10−4 mm2/s) at all time points (P < 0.05) [Figure 3a].

Bottom Line: 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 4 th day; f values decreased on all stripes; D values had a tendency to increase with fluctuations but the changes didn't achieve statistical significance; DFNx01 values increased at the 2 nd day then tended to be steady thereafter.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Tianjin Medical University Hospital, Tianjin, China.

ABSTRACT

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 2 nd day, 4 th day, 6 th day, 8 th day, 2 nd week, 3 rd week and 4 th 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 DFNx01 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 4 th day; f values decreased on all stripes; D values had a tendency to increase with fluctuations but the changes didn't achieve statistical significance; DFNx01 values increased at the 2 nd day then tended to be steady thereafter. Pathological findings revealed tubules epitheliums swelling followed by inflammation cells infiltration, interstitial fibrosis was observed since the 2 nd 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.

Show MeSH
Related in: MedlinePlus