Study Of RESOLVE-DWI And Dynamic Contract-enhanced Magnetic Resonance MRI In The C6 Glioma Model With Wistar Rat

Purpose: To evaluate the image quality of readout segmentation of long variable echo-trains diffusion weighted imaging (RESOLVE-DWI) in C6 glioma model of wistar rat.Methods: The RESOLVE-DWI (Experimental Group), conventional SS-EPI-DWI (Control Group) and conventional weighted images were acquired by using established C6 glioma model with Wistar rats at 3.0T MRI. The signal intensity (SI) of tumor and the normal tissue in control-lateral, the standard deviation (SD) of background were measured and the signal to noise ratio (SNR), contrast to noise ratio (CNR) and ADC values were calculated. To evaluate the distortions of the DWI images, the distortion distances (DD) of borders between DWI b=0 mm-2s and T1WI anatomical images were measured. All the quantitative parameters were analyzed using Paired t-test. The whole image quality were scored on the basis of subjective four-point image quality scales and the indexes were analyzed using Wilcoxon signed rank test. A P<0.05 indicate statistically significant difference.Results: The SNR and CNR of experimental group were higher than control group [SNR:68.16±9.11 vs 32.84±5.25,t= 10.67,P<0.05 ; CNR: 23.34±4.78 vs 12.87±3.54,t=5.88,P<0.05]. The DD values of experimental group were lower than control group in image distortion evaluation [DDI: (0.01±0.04)vs(0.09±0.11)cm; DD2: (0.03±0.04) vs (0.14±0.13)cm;DD3: (-0.06±0.05) vs (-0.24±0.11)cm; DD4: (0.16±0.06) vs (0.43±0.18)cm; DD5: (0.09±0.04)vs (0.31 ±0.17)cm,P<0.05]. In subjective evaluation,the SQS of experimental group were obviously higher than the control group with significant statistical difference (3.6±0.5vs 1.7±0.6, P<0.05). No statistical difference in ADC values between the two groups were found[tumor:(1.00 ±0.122)×10-3mm2sec-1 vs(1.02 ± 0.230)×10-3mm2sec-1; contralateral brain tissue :(0.69±0.031)×10-3mm2sec-1 ?(0.71 ±0.062)×10-3mm2sec-1,P>0.05].Conclusion: DW imaging based on RESOLVE DWI provided significantly higher image quality than SS-EPI DWI in C6 glioma model of wistar rat MRI at 3.0T, and the ADC values repeatability seemed can be improved.Purpose:To evaluate the image quality of Dynamic contract-enhanced magnetic resonance MRI in C6 glioma model of wistar rat MRI.Methods:20 healthy Wistar rats weighted 250-300g were selected and injected with C6 cells in rigth caudate nucleus.All rats were examined with 3.OMR including conventional MRI and DCE-MRI.Results:Two weeks after C6 cell implantation,MR images show hyper-intensity on T1-weighted images and T2-weighted images and with homogeneously enhanced after injected Gadopentetate dimeglumine;The difference of average Ktrans[ (0.017±0.003)vs(0.001 ±0.001)min-1]?Kep [ (0.287±0.08) vs (0.182±0.02) min-1]and Ve [ (0.104±0.02) vs (0.01±0.005) ]value between C6 glioma region and the contralateral normal brain is significant.In the tumor,there were high correlation between Ktrans and Kep(r=0.802 P<0.001 ); removing the effect of Kep,Ktrans were positively correlate with Ve(r=0.558 P<0.05);removing the effect of Ktrans,Kep were negatively correlate with Ve(r=-0.830 P<0.001).Conclusion:It is feasible to do DCE-MRI in C6 glioma model with 3.OMR ; the Ktrans and Ve values were higher than the contralateral normal brain,removing the effect of Kep,Ktrans were positively correlate with Ve ;removing the effect of Ktrans,Kep were negatively correlate with Ve.