The Application Of Magnetic Resonance Diffusion Tensor Imaging And Perfusion Weighted Imaging In The Pathology Of Meningioma And Its Surgical Treatment

Objective: This study introduce to the value of magnetic resonance diffusion tensor imaging(DTI)and perfusion weighted imaging(PWI)in the pathology grade of meningioma,approach correlation among strategies of surgical treatment,in order to provide quantitative data and estimate of outcome functional.Methods :Twenty-one patients with meningioma were all confirmed by operation and pathology in the second affiliated hospital of Southwest Medical University from June 2015 to January 2017.Each patient was performed with precontrast T1 weighted imaging(T1WI),T2 weighed imaging(T2WI),DTI and PWI examination.According to the 2007 WHO classification of meningioma,grade I meningioma was divided into benign tumor(group A),grade II and III meningiomas were divided into malignant tumor(group B).Data acquisition of DTI and PWI was processed on postprocessing work station after scanning.ADC and rCBV values were measured in the solid part of tumors,the peritumoral edema and contralateral corresponding normal brain white matter and color pictures were drawed.In the study of FA value of different pathological types,thepatients were divided into three groups according to pathological classification.The first group was atypical and malignant meningioma,the second group was fibrous meningioma,and the other third groups were benign meningiomas.The consistency of meningiomas was defined as soft(removed with suction),medium(some part soft and some hard),and hard(non-suckable,requiring scissors or ultrasound tumor devices)by the operating surgeon.After the meningiomas were operated,they were examined histologically using both hematoxylin and eosin(HE)patho-examination and immunohistochemical staining for vascular endothelial growth factor(VEGF)and microvascular density.The post-operative Karnofsky Performance Status(KPS)of patients with or without DTI were compared at preoperative,2 week and 1 and 3 months after operation.All the measurement results were demonstrated with mean± standard deviation(X± S).Each set of data varied between the groups was compared using one-way ANOVA.Two-sample mean comparison used t test.Statistical comparisons of the tumor cells with the ADC values of the tumoral region,and VEGF expression score with maximal rCBV values of the tumoral region were made by Pearson correlation analysis.Statistical comparisons of the ADC values in tumoral region with tumor grade,and maximal rCBV values in tumoral region with tumoral grades were made by Spearman correlation analysis.The Kruskal-Wallis Test was used to analyze KPS scores.Statistical analysiswere Performed with SPSS17.0 software and a= 0.05 was taken as test standard.Results: Statistical discrepancies of the ADC values in solid part of meningioma for both group A and group B were present(P<0.05).There were no significant differences of ADC values in peritumoral edema of meningioma and the contralateral corresponding normal brain white matter between group A and B(P>0.05).Statistical discrepancies of the maximum rCBV values in solid part of meningioma and the peritumoral region for both group A and group B meningiomas were present(P<0.05).There were no significant differences of FA values in both peritumoral edema of meningioma and the solid part of meningioma between group A and B(P>0.05).The maximum rCBV value for the solid part of meningioma for both group A an d group B was increased with the increase of VEGF expression and MVD,they had positive correlation with tumor VEGF expression and MVD(P<0.05).FA value > 0.3 were associated with hard-consistency tumors.The post-operative KPS of patients with DTI were better than those without DTI at 2 week,1 and 3months after surgery(P<0.05).Conclusion: ADC and rCBV values may predict the malignancy of meningiomas.FA value and MD and FA maps are useful for prediction of meningioma consistency.Fiber tracking maps provide the information regarding the detailed relationship between meningiomas and nearby white matter tracts.Combined with conventional MR imaging,DTI can provide important information inplanning brain tumor surgery and prognosis.