The Value Of MAP-MRI And DCE In Differentiating Glioblastoma From Brain Metastases

Objective:To explore the clinical value of mean apparent propagator magnetic resonance imaging（MAP-MRI）and dynamic contrast-enhanced（DCE）in differentiating glioblastoma（GBM）from brain metastases（BMs）.Methods:27 patients with glioblastoma[isocitrate dehydrogenase-wildtype（GBM,IDH-wt）]who were confirmed by surgery and 24 patients with BMs confirmed by surgery or clinical follow-up performed conventional MRI sequences,diffusion spectrum imaging（DSI）and DCE.The parameters of MAP-MRI were obtained by DSI analysis.And the parameters of DCE are processed by Siemens workstation.The parameters of the tumor parenchyma area and peritumoral edema area and the contralateral normal brain tissue in these two groups were measured on each parameter map.In order to minimize individual differences,the values of each parameter were divided by the values of the contralateral normal brain tissue to obtain the relative values of each parameter.χ²test was used to compare the gender of the two groups;independent samples t-test and Mann-Whitney U-test were used to compare the parameters and relative parameters of MAP-MRI and DCE between the two groups.P<0.05 was considered to be significant.Then drew the ROC curve.Delong test was used to evaluate the differential diagnosis efficiency of each parameter.Results:There was no significant difference in age and sex between the two groups（P=0.327 and P=0.247）.In GBM（IDH-wt）group,the non Gaussian axial（NGAx）,non Gaussian vertical（NGRad）,return to the axis probability（RTAP）and return to the plane probability（RTPP）were higher than those of BMs group,and mean square displacement（MSD）was lower than that in BMs group,and the difference was significant（P<0.05）.The relative volume transfer constant(r K^trans)of peritumoral edema area in GBM（IDH-wt）group was higher than that in BMs,while the relative rate constant(r K_ep)was lower than that in BMs group,and the difference was significant（P<0.05）.RTPP and NGAx of tumor parenchyma area are the parameters with higher AUC when differentiating GBM（IDH-wt）from BMs.The AUC is 0.985and 0.937,and the sensitivity is 0.963 and 0.926,and the specificity is 0.917、0.837,respectively.Conclusion:MAP-MRI and DCE showed great diagnostic value in differentiating GBM（IDH-wt）from BMs.RTPP and NGAx in tumor parenchymal area could be used as good imaging markers.