The Value Of DTI And DWI In Grading And Differential Diagnosis Of Gliomas

PART1 THE VALUE OF DTI QUANTITATIVE PARAMETERS OF PERITUMORAL EDEMA AREA IN THE GLIOMAS GRADINGPurposeTo investigate the value of relative fractional anisotropy(rFA)and relative apparent diffusion coefficient(rADC)in diffusion tensor imaging(DTI)of different regions of glioma around the near,middle and distal regions in its high and low level identification.MethodsThe DTI data of 48 patients(30 cases of high grade,and 18 cases of low grade)with gliomas confirmed by pathology were analyzed retrospectively.Taking the axial of the largest level of edema line,the value of FA and ADC of the peritumoral edema in near,middle and far regions from the tumors and the FA value as well as ADC value of the normal white matter region of the contralateral hemisphere mirror were measured.The rFA(rFAl,rFA2,rFA3)and rADC(rADC1,rADC2,rADC3)in different regions of the peritumoral edema area were calculated,their changes and differences in high and low-grade gliomas were analyzed.ResultsThe rFA1,rFA2 and rFA3 in the edema area of the high-grade group were lower than those of the low-grade group(P<0.05).The rADC1,rADC2 and rADC3 in the edema area of the high-grade group were higher than those of the low-grade group(P<0.05).ROC analysis showed the area under the curve of rFAl,rFA2,rFA3,rADC1,rADC2 and rADC3 were 0.972,0.893,0.854,0.743,0.761 and 0.694,respectively.There were significantly statistical differences between rFAland rFA2,and between rFAl and rFA3(P<0.05),while there was no difference between rFA2 and rFA3(P>0.05).There was no significantly statistical differences between rADC1,rADC2 and rADC3(P>0.05).There were significantly statistical differences between rFA1 or rFA2 and rADCl,rADC2,rADC3(P<0.05).There was no difference between rFA3 and rADC1,rADC2(P>0.05).ConclusionIn the near,middle and far regions of peritumoral edema area,quantitative parameters of DTI,rFA value and rADC value in the differential diagnosis of gliomas have a certain value.But the diagnostic efficiency of rFA value is significantly better than that of rADC.PART2 ADC,EADC AND THEIR RELATIVE VALUES IN DIFFERENTIATION OF GRADE II GLIOMASPurposeTo study the differences of apparent diffusion coefficient(ADC),exponential apparent diffusion coefficient(EADC)and their relative values in the parenchymal regions among different pathological types of WHO grade ? glioma.MethodsThe clinical data of 51 patients of WHO grade II gliomas proved by pathology in the brain were retrospectively analyzed,including 30 cases of astrocytomas(AC),15 cases of oligodendrogliomas(OD)and 6 cases of oligoastrocytomas(OA).The ADC,EADC,relative ADC(rADC)and relative EADC(rEADC)in parenchymal regions of the tumors were measured and calculated,then the differences of the parameters of the three groups were compared,and the receiver operating characteristic curve(ROC)was used to determine the cut-off value,sensitivity and specificity for differential diagnosis between AC and OD+OA.ResultsThe values of ADC?EADC?rADC and rEADC in the parenchyma of the tumors were significant different(P<0.05)between AC and OD,AC and OA,but there were no significant differences(P>0.05)between OD and OA.ROC curve analysis showed that the areas under the curves were all greater than 0.9,and the diagnostic sensitivity and specificity were all more than 80%,when the values of 1.150×10-3mm2/s,0.311,1.512 and 0.691 were respectively used as the cut-off values for ADC,EADC,rADC and rEADC.ConclusionThe ADC,EADC,rADC and rEADC may be helpful in differentiating OD or OA from AC,but there are some limitations between OD and OA.A higher and similar diagnostic efficacy of these parameters is found for the identification between AC and OD+OA.