The Diagnostic Value Of IVIM-DWI And DKI In The Pathological Grading Of Glioma

The first part:application of IVIM-DWI in grading of gliomaObjective To evaluate the diagnostic capability and performance of intravoxel incoherent motion(IVIM)MR imaging and dynamic susceptibility contrast(DSC)perfusion imaging in grading of glioma,and evaluate the correlation in perfusion parameters derived from IVIM and DSC imaging.Methods Forty-four patients with glioma were performed preoperative IVIM diffusion-weighted imaging and dynamic susceptibility contrast(DSC)perfusion imaging at 3.0T.IVIM true diffusion parameter D,perfusion parameters including D*,f,BF,traditional apparent diffusion coefficient(ADC)and DSC perfusion parameters including cerebral blood volume(CBV),cerebral blood flow(CBF),mean transit time(MTT),time to peak(TTP)were measured using software.Assess the difference between high-grade gilomas and low-grade gliomas with these parameters,evaluate the correlation in perfusion parameters derived from IVIM and DSC imaging methods and analyse the diagnostic performance using receiver operating characteristic(ROC)curve.Results 44 cases of glioma include 27 high-grade gliomas and 17 low-grade gliomas.High-grade group lesions parameters ADC,D,D*,f values were(988.92±203.67)×10-6mm2/s?(955.41±241.40)×10-6mm2/s?(6018.52±1523.30)×10-6mm2/s85.81±30.17)10-3%?(639.05 ±242.94)×10-6mm2/s;CBV,CBF,MTT,TTP values were(2009.51 ±899.93)ml/min/100g?(352.65± 159.31)ml/min/100g?(1150.13±593.87)ml/min/100g?(2790.71 ±551.95)ml/min/100g;low-grade group lesions parameters values were(1126.10±256.87)?10-6mm2/s?(1164.82±305.18)×10-6mm2/s?(5049.43±837.53)×10-6mm2/s?(57.20±20.69)10-3%?(385.47±136.24)×10-6mm2/s;(854.29±64.16)×ml/min/100g?(216.67± 167.51)ml/min/100g?(887.83 ±47.56)ml/min/100g?(2943.31± 161.06)ml/min/100g.D was significantly lower in the high-grade gliomas than the low-grade gliomas(P=0.015),IVIM perfusion parameters D*,f,BF and CBV,CBF were significantly higher in the high-grade gliomas than the low-grade gliomas(P =0.019,0.002,0,000;0.000,0.024),ADC,MTT,TTP were not different between groups(P=0.092,0.162,0.280).CBV,CBF were correlated with D*(P=0.024?r=0.361;P=0.023?r=0.358),f(P=0.001?r=0.524;P=0.002?r=0.467)and BF(P=0.000?r=0.716;P=0.000?=0.572).BF showed the strongest correlation with CBV and CBF.The AUC of ADC,D,D*,f,CBV,CBF,MTT,TTPwere0.669?0.718?0.683?0.758?0.804?0.813?0.603?0.690?0.421.Among these parameters,DSC-CBV showed the highest diagnostic performance in grading of glioma,which was little higher than IVIM-BF.Conclusion As a noninvasive quantitative method,IVIM diffusion weighted imaging supplies the diffusion and perfusion information.IVIM diffusion parameter and perfusion parameters showed significant difference between high-grade gilomas and low-grade gliomas.Among them,BF showed the strongest correlation with CBV and the highest diagnostic performance in grading of glioma.Thus,IVIM parameters,especially BF value,offer great diagnostic value in preoperative grading gliomas and will hopefully replace the traditional DSC in the future.The second part:application of DKI in grading of gliomaObjective To evaluate the diagnostic capability and performance of diffusion kurtosis imaging(DKI)in grading of glioma.Methods Thirty patients with glioma were performed preoperative DKI at 3.OT.DKI diffusion parameters including mean diffusivity(MD),axial diffusivity(DA),radial diffusivity(DR),kurtosis parameters including mean kurtosis(MK),axial kurtosis(KA),radial kurtosis(KR)and fractional anisotropy(FA)were measured using DKE software.These parameters were also normalized to the corresponding values in contralateral normal-appearing white matter(NAWM),as relative values including rDA,rDR,rMD,rKA,rKR,rMK,rFA.Compared with histologic grade,assess the difference in grading of glioma with DKI parameters and analyse the diagnostic performance using receiver operating characteristic(ROC)curve.Results 30 cases of glioma include 19 high-grade gliomas and 11 low-grade gliomas.High-grade group lesions parameters DA,DR,MD,KA,KR,MK,FA and relative values including rDA,rDR,rMD,rKA,rKR,rMK,rFA values were(1.49±0.32)X 10-3mma/s?(1.17±0.29)X10-3mm3/s?(1.29±0.32)X10-3mmz/s?(0.76±0.13)?(0.76±0.12)?(0.76±0.11)?(0.19±0.08)?(1.12±0.23)?(1.13±0.25)?(1.14±0.26)?(0.98±0.21)?(0.97±0.18)?(0.99±0.18)?(1.13±0.62);low-grade group lesions parameters values were(1.53±0.27)X10-3mm2/s?(1.16±0.29)X10-3mm2/s?(1.29±0.28)×10-3mm2/s?(0.62±0.11),(0.61±0.14)?(0.60±0.13)?(0.20±0.07)?(1.19±0.25)?(1.17±0.36)?(1.18±0.31)?(0.76±0.13)?(0.79±0.15)?(0.77±0.14)?(1.13±0.30)?DKIkurtosis parameters including KA,KR,MK and rKA,rKR,rMK were significantly higher in the high-grade than the low-grade gliomas(P =0.021?0.017?0.005?0.003?0.008?0.002),DA,DR,MD,FA and their relative values were not different between groups(P=0.651?0.914?0.983?0.426?0.505?0.949?0.914?0.237).The area under the ROC curve(AUC)of DA,DR,MD,KA,KR,MK,FA and relative values rDA,rDR,rMD,rKA,rKR,rWK,rFAvalues were 0.669?0.718?0.683?0.698?0.804?0.813?0.603?0.690?0.421.Among these parameters,MK and rMK showed the highest diagnostic performance in grading of glioma.Conclusion As a noninvasive quantitative method,DKI based on non-Gaussian diffusion model,characterizes molecular diffusion and changes of micro structure in central nervous system.DKI kurtosis parameters and their relative values,especially MK and rMK value,showed significant difference between high-grade gilomas and low-grade gliomas.DKI has more advantages of evaluating grading in glioma.