The Application Study Of ESWAN In The Grading Of Gliomas And Dis-crimination Between Gliomas And Solitary Brain Metastases

Objective To explore the application value of ESWAN （Enhanced T₂Star Weighted Angiogra-phy） sequence in the grading of gliomas and discrimination between high-grade gliomas andsolitary brain metastases.Materials and Methods Fifty cases of intracranial tumors underwent conventional MR imag-ing and ESWAN scanning before treatment. All cases, which were proved by pathology orclinical history, were divided into three groups including low-grade gliomas, high-grade gli-omas and solitary metastases. Conventional MR imaging and ESWAN data were analyzed. Allraw data of ESWAN were post-processed by software of ADW4.5, to acquire min IP （minimumintensity projection）, R₂*and T₂*maps. The following data were recorded:（1） Bleeding index,which is defined as the ratio of the volume of hemorrhage to that of tumor, was calculated onmin IP maps.（2） ITSS （intratumoral susceptibility signal intensity） was rated on min IP maps.（3） R₂*and T₂*values in tumoral parenchyma, peritumoral immediate-oedema and normalwhite matter tissue were measured on R₂*and T₂*maps. All data were statistically analyzed bySPSS （statistics package for social science）19.0software.Results Thirty-eighty cases were enrolled into this study, including11cases of low-grade gli-omas,16cases of high-grade gliomas and11cases of solitary metastases.27cases of gliomasand5cases of metastases were proved by pathology.6cases of metastases were proved byclinical history.（1） Bleeding index between low-grade gliomas and high-grade gliomas differedsignificantly （P<0.001）.（2） The score of ITSS in low-grade gliomas was lower compared tothat in high-grade gliomas （P<0.001）. There was significant correlation between pathologicalgrading of gliomas and ITSS score （r=0.763，P<0.001）. The ROC curve showed ITSS score hada high diagnositic value on histological grading of gliomas, the area under the curve was0.942.The sensitivity and specificity of diagnosing high-grade gliomas was93.3%and81.8%.（3）Compared to that of normal brain tissue, R₂*value of tumoral parenchyma and peritumoralimmediate-oedema in low-grade gliomas, high-grade gliomas and solitary metastases decreasedsignificantly （P<0.05）, while T₂*value increased markedly （P<0.05）. There was statistic signi-ficance of R₂*and T₂*value between high-grade gliomas and metastases in peritumoral imme-diate-oedema （P<0.001）. Conclusion （1） Application of ESWAN to evaluate bleeding index and ITSSs can provide as-sistance in grading of gliomas.（2） R₂*and T₂*values in peritumoral immediate-oedema arevaluable in differentiation between high-grade gliomas and solitary brain metastases.