Application Value Of 3D-ASL Combined With DKI Technology In Cerebral Alveolar Echinococcosis

Object: To investigate the biological and perfusion characteristics of cerebral alveolar echinococcosis(CAE)through the conventional magnetic resonance imaging,diffusion weighted imaging(DWI),three-dimensional arterial spin labeling(3D-ASL)and diffusion kurtosis imaging(DKI)sequences and to differentiate CAE from brain metastases(BM)so as to improve the diagnostic level.Method: All patients underwent conventional MRI,DWI,DKI and 3D-ASL scanning on a 3T MR scanner(MAGNETOM Prisma,Siemens Healthcare,Erlangen,Germany).24 patients with CAE were diagnosed by clinical,pathological or other imaging methods.The number,size,location,edema volume,edema index and the number of vesicles of CAE patients(86 lesions),and the diagnostic value of MRI sequences(DWI,DKI,3D-ASL)in the different areas(parenchymal area,marginal area and edema area)of the lesions were analyzed.The values of the DKI parameters(Kmean,Krad,Kax,Dmean,Drad,Dax and FA),ADC and CBF were measured in the different areas(parenchymal area,marginal area and edema area)of all lesions.These parameters were compared with the average value of contralateral normal brain tissue to obtain the standardized values of these parameters.And the correlation between the lesion volume and the edema volume around the lesion,and the correlation between the number of vesicles and lesion volume were compared.The standardized values of these parameters(nADC,nKmean,nDmean,nFA and nCBF)in the parenchyma and edema area of the two groups of 24 patients with CAE(86 lesions)and 16 patients with BM(69 lesions)were measured respectively.The independent sample t-test was used for statistical analysis,and we evaluated the efficacy of various parameters in distinguishing patients with cerebral alveolar echinococcosis and brain metastases.Result: There were 86 lesions in 24 patients with CAE.The values of Kmean,Krad,Kax,FA and CBF in the marginal area of the lesions were significantly higher than those in the parenchyma,edematous and normal areas(P<0.001).The values of Dmean,Drad and Dax in the marginal area of the lesion were lower than those in the parenchyma,edematous and normal areas(P<0.01).The value of ADC in the marginal area of the lesions were significantly lower than those in the edematous areas and the parenchyma area(P<0.01).The values of Kmean,Krad,Kax and ADC in parenchyma and edematous areas were higher than those in contralateral normal brain areas(P<0.001).The values of Dmean,Drad,Dax,FA and CBF in parenchyma area and edematous areas were lower than those in contralateral normal brain area(P<0.05).The statistical values of edema volume and edema index on MRI plain scan of CAE lesions were(230.73 ±336.09)cm~3 and 11.58 ±14.11.There was a positive correlation between the lesion volume and edema volume and between the number of vesicles and the volume of the lesion in CAE(r=0.855,P<0.001;r=0.639,P<0.001).There were significant differences in nKmean,nDmean,nFA and nCBF in the parenchyma area between CAE and BM(P<0.01),but there was no difference in nADC value in the parenchyma area(P>0.05).There were significant differences in nKmean,nDmean,nFA,nCBF and nADC in the edematous area between CAE and BM group(P<0.05).The results of ROC curve analysis showed that the sensitivity and specificity of n CBF value in the parenchyma of the two groups were higher,the area under the curve was the largest,and the sensitivity and specificity of n Kmean in the edema area of the two groups were higher,and the area under the curve was larger.Therefore,we can evaluate the efficacy of these parameters in differentiating CAE from BM.Conclusion: Conventional magnetic resonance imaging combined with DWI,DKI and 3D-ASL imaging techniques can study the biological characteristics of marginal,edema areas and the vesicles of CAE lesions,the degree of destruction of blood-brain barrier and the formation of neovascularization at the molecular level and explore the relationship between lesion volume and the edema volume of CAE and the relationship between the number of vesicles and lesion volume of CAE.It provides a new idea for the diagnosis,determination of marginal zone and active characteristics of CAE.Multiple high-signal-intensity vesicles on T2-weighted images inside and around the lesions of CAE are the characteristic MRI findings in the differential diagnosis of CAE and BM.The quantitative parameters of DWI,DKI and 3D-ASL are of great value in differentiating CAE from BM.