Application Of Synthetic MRI Combined With Multiplexed Sensitivity-Encoding Diffusion-Weighted Imaging To Differentiate Glioma Progressive Disease From Treatment-Related Changes

Objective:The purpose of this study was to assess the utility of synthetic MRI（sy-MRI）quantitative parameters and multiplexed sensitivity encoding diffusion weighted imaging（MUSE-DWI）in combination to differentiate glioma progressive disease（PD）from treatment-related changes（TRCs）.Materials and methods:In this study,we collected 45 patients who exhibited new enhancing lesions after surgery followed by completion of chemoradiation therapy from September 2020 to November 2022 in the General Hospital of Ningxia Medical University.All patients underwent MR exams with a 3.0T MR scanner（SIGNATM Architect,GE Healthcare,USA）and the scan sequences included synthetic MRI,MUSE-DWI and contrast-enhanced T1FLAIR（T1FLAIR+C）.The patients were classified into two groups according to m RANO:the PD group（n=26）and the TRCs group（n=19）.The ADC maps derived GE ADW4.7workstation and quantitative synthetic MRI maps obtained by the host system MAGi C software.Two radiologists with more experience in neuroimaging diagnostics who were both blinded to the patient histology at repeat surgery or biopsy and MR data of final follow-up results placed separate circular ROIs on each map corresponding to the T1WI+C images enhancement regions.Three ROIs are placed on each image to measure ADC value,pre-contrast T1,T2 value（T₁-pre,T₂-pre）and post-contrast T1,T2 value（T₁-post,T₂-post）,and then calculate the mean values.MRI quantitative parameters（T₁-pre,T₂-pre and T₁-post,T₂-post）and ADC were evaluated using Student’s t-test or Mann–Whitney U test.We generated receiver operating characteristic（ROC）curves for each parameter and their combinations and determined their sensitivity,specificity,and optimal cut-offs.Finally,we used the area under the ROC curve（AUC）to assess the performance of each parameter and their combinations.Results:1.Comparison of synthetic MRI quantitative parameters and ADC value between PD and TRC:There were significant differences in T₁-pre,T₁-post and ADC values between the PD and TRC group.The T₁-pre value in the PD group were significantly higher than the TRC group（P<0.05）.The values of T₁-post and ADC in the PD group were significantly lower than the TRC group（all P<0.05）.There was no statistical difference in T₂-pre,T₂-post value（P>0.05）.2.Diagnostic performance of synthetic MRI quantitative parameters（T₁-pre,T₁-post）,ADC values and their combinations:ADC diagnostic performance was highest when using single parameter analysis（AUC=0.878）,followed by T₁-post and T₁-pre with AUC of 0.783and 0.745,respectively.The combinations of two parameters（T₁-pre+T₁-post）improved the diagnostic performance（AUC=0.850）compared to the single parameter.A combined multi-parameter model（T₁-pre+T₁-post+ADC）was established with the highest diagnostic efficacy（AUC=0.901）,sensitivity of 92%and specificity of 84%,and the combined model had higher diagnostic performance in differentiating PD from TRCs.Conclusion:This study takes advantage of the quantitative parameters of synthetic MRI provides information with tissue characteristics,and the imaging advantage of MUSE-DWI technique reduces geometric distortion to provide high-resolution images.The combinations of the two techniques to construct a multiparametric combined model of relaxation quantitative parameters（T₁-pre,T₁-post）combined with ADC values can more effectively identify glioma PD and TRCs,and can provide an imaging basis for postoperative clinical management of glioma.