Application Of Magnetic Resonance Imaging In Predicting Phenotypic Characteristics Of Glioma IDH Gene

Objective:This study is to investigate the difference of conventional magnetic resonance imaging and advanced magnetic resonance imaging(diffusion tensor imaging)in glioma patiens with different isocitrate dehydrogenase(IDH)gene mutation status.And explore the diagnostic performance of magnetic resonance imaging and DTI in differentiating IDH mutant gliomas and IDH wild type gliomasMethods:This study contains 2 parts.In the first section,we retrospectively enrolled 221 glioma patients with molecular pathology in detail,all those patients were underwent the conventional MRI examination before the surgery.All tumors were segmented on MR images,and were registered onto the standard brain space.According to IDH mutations status,the cases were divided into two groups.The basic information,the tumor size and the volume of edema area,and the difference of tumor location information were analyzed.Based on the difference between the two groups,some features related with IDH mutation state were obtained.In the second section,221 glioma patients of tensor tensor imaging(DTI)of molecular pathological features were retrospectively reviewed from January 2016 to December 2017.The tumor edema area was segmented,and the volume of the tumor edema and the core area of the tumor were measured,and the free water imaging(FW)mean,mean standard deviation,median,minimum,maximum,fractional anisotropy(FA)mean,mean standard deviation,median,minimum,maximum,mean diffuse(MD)mean,mean standard deviation,median,minimum,maximum value were calculated.According to the molecular pathological results,the cases were divided into IDH mutation group and IDH wild type group,and the difference of FW,FA and MD values between IDH mutation group and IDH wild type group in different tumor types were compared.The receiver-operating characteristic curve(ROC)curve is drawn for the statistically significant indicators,and the cut-off value of each image index and its corresponding sensitivity,specificity,accuracy,and diagnostic odds ratio are obtained.By comparing the area under each indicator curve,an optimal diagnostic prediction model for predicting glioma IDH mutation was obtained and established.Results:In the first section,IDH mutant glioma patients were younger than IDH wild-type patients(40.2 ± 10.0 years vs 47.7 ± 15.8 years,P<0.01),and the difference in glioblastoma patients group were the most obvious.Cases with IDH mutations had larger tumor edema volumes compared to wild-type tumors(15.48 ± 11.40 cm3 vs 11.59± 9.30 cm3,P=0.02).In the whole tumor volume analysis,astrocytoma and glioblastoma IDH mutant tumors have a larger overall volume than wild-type tumors(20.36± 13.70cm3 Vs 8.68 ± 12.05cm3,32.51 ± 10.63 cm3 Vs 25.11± 10.44cm3).Tumor superimposed results show that,in general,IDH mutant tumors are often located in the left frontal white matter,IDH wild-type tumors are often located in the left insular white matter or insular cortex,and glioblastoma IDH mutants cases were more vulnerably locating at the midline forefront of the white matter,while glioblastoma IDH wild-type tumors were more vulnerably locating at the bilateral white matter of the insular and part of the frontal white matter.In the second part,the mean standard deviation of the FW edema area the FW edema area minimum value,the FA mean standard deviation,and the FA median and minimum values were significantly different during the overall group.In astrocytoma,the sensitivity/specificity of mean standard deviation of the FW edema area the FW edema area minimum value,the FW edema area maximum value,and the tumor edema area volume were 83/59%,91/59%,43/84%,and 74/95%in identifying IDH mutant and wild type groups,respectively.The area under the diagnostic curve(AUC)were 0.70,0.81,0.62,and 0.83,respectively.The combined diagnostic predictive model were obtained by combining FW value,FA value and MD value,which had a diagnostic sensitivity/specificity of 87%/90%and the AUC of 0.91 as a high diagnostic performance.The diagnostic sensitivity/specificity of the combined diagnostic prediction model of glioblastoma combined with FW value,FA value and MD value was 90%/100%,and the AUC was 0.98,which has high diagnostic value.The diagnostic prediction model of the oligdendroglioma combining with the FW minimum of the FW tumor area and the FA maximal value of the tumor core area tumor had 100%specificity,and the AUC was 0.80,which was robustConclusions:The IDH mutant glioma patients are younger than IDH wild-type patients and have larger tumor edema volume.Significant differences of tumor location were founded between the IDH mutant and IDH wild-type groups.The advanced parameters FW,FA and MD values derived from DTI sequence had a good diagnostic performance in identifying glioma IDH mutants and IDH wild type.