The Value Of Conventional MRI In The Diagnosis And Treatment Of Diffuse Gliomas In Adults And The Value Of IVIM In The Grading Of Diffuse Gliomas In Adults

Objective:By summarizing the conventional MRI findings of diffuse gliomas in adults and analyzing the diagnostic accuracy of different types of diffuse gliomas in adults,to evaluate the value of conventional MRI sequences in the diagnosis and treatment of diffuse gliomas in adults.Methods:The clinical data of 79 adult patients with diffuse glioma confirmed by pathology in Anhui Provincial Hospital of the First Affiliated Hospital of University of Science and Technology of China from June 2017 to July 2022 were retrospectively analyzed.Conventional MRI was performed preoperatively,including conventional transverse,sagittal and coronal T₁WI and T₂WI;fluid-attenuated inversion recovery sequence;diffusion-weighted imaging and conventional enhanced T₁WI.After the diagnosis of physicians who had relevant experience more than 5 years,the routine MRI diagnosis results were compared and analyzed with the pathological results,and the conventional MRI imaging manifestations of different pathological types of adult diffuse glioma were summarized and the diagnostic accuracy was analyzed.Results:The MRI manifestations of the astrocytoma were not consistent,mainly showing unclear border,and T₁WI showed low signal,while T₂WI showed high signal.There were different degrees of edema in the periphery,and the enhancement of the astrocytoma showed different degrees of enhancement,most of them have limited diffusion.Oligodendroglioma is mainly frontal and temporal cortex or subcortical,with unclear boundaries,with different degrees of peritumoral edema,enhanced to varying degrees of enhancement,and it’s diffusion is mainly mildly limited.The Glioblastoma multiforme showed mixed low signal intensity on T₁WI and mixed high signal intensity on T₂WI,with blurred border,extensive infiltration,obvious edema and irregular garland-like enhancement.The accuracy of conventional MRI sequence in the diagnosis of diffuse gliomas in adults was 91.14%,47.37%for low-grade gliomas and 31.67%for high-grade gliomas;the diagnostic accuracy of astrocytoma,oligodendrocyte and Glioblastoma multiforme were 3.57%,16.67%and 18.42%respectively.Conclusion:1.Conventional MRI sequences have high detection value for adult diffuse gliomas,but the diagnostic value is low.2.The diagnostic ability of conventional MRI sequences for high and low grade gliomas in adult diffuse gliomas is poor,and the diagnostic ability of low grade adult diffuse gliomas is slightly better than that of high grade.3.Diffuse gliomas in adults occur more frequently in men.4.Conventional MRI sequences have poor diagnostic ability for astrocytoma,oligodendroglioma and glioblastoma.Among them,conventional MRI sequences have relatively strong diagnostic ability for glioblastoma,and have the worst diagnostic ability for astrocytoma.5.The imaging manifestation of astrocytoma,oligodendroglioma and glioblastoma are partially overlapped.Conventional MRI has limited application value in their mutual identification.6.Conventional MRI sequences play an important role in the detection and diagnosis of adult diffuse gliomas,assisting clinical decision-making.However,the ability to further classify diffuse gliomas is poor,and other MRI sequences are needed to assist in differential diagnosis.Objective: By analyzing the diagnostic efficacy of intravoxel incoherent motion in adult diffuse glioma grading and the correlation between diffusion parameters,the application value of IVIM in adult diffuse glioma grading was evaluated.Methods: The clinical data of 48 cases in the First Affiliated Hospital of University of Science and Technology of China were retrospectively analyzed.All the 48 cases were confirmed as diffuse glioma in adults by surgical pathology.According to the pathological results,they were divided into high grade glioma（HGG）group（39 cases）and low grade glioma（LGG）group（9 cases）.Preoperative axial,coronal,sagittal conventional T1 WI,T2WI and enhanced scan,DWI（b value of 0 and 1000 s/mm2）,IVIM-DWI（b value of 20,50,100,200,400,600,800,1000,1500,2000 s/mm2）scan had been done.The IVIM images were post-processed on the GE AW Volum Share7 workstation.The region of interest was selected in the parenchymal part of the lesion,the perifocal edema area and the mirror-side control area of the lesion.When the region of interest was drawn,areas such as the bleeding,necrosis,calcification were avoided to obtain the apparent diffusion coefficient,true diffusion coefficient,false diffusion coefficient and perfusion fraction values.Two independent sample t-test was used to compare the differences of IVIM parameters between HGG and LGG groups and between grades in the parenchymal part of the lesion,the perifocal edema area and the mirror-side control area of the lesion.The correlation between parameters wasanalyzed by Graph Pad Prsim 6.01 software,and the diagnostic performance of IVIM parameters was analyzed by ROC curve.Results: The ADC values and D values in HGG group were lower than those in LGG group（p<0.05）,the D* value of HGG was significantly higher than that of LGG（p<0.05）.Only the D value had significant difference between Ⅱ and Ⅲ grades（p<0.05）.There were significant differences in ADC,D,D* and f values between Ⅱ and Ⅳ grades（p<0.05）.There were no statistical differences in ADC,D,f values between Ⅲ and Ⅳ grades（p> 0.05）.ROC curve showed that the AUC of D value was higher than that of ADC value in distinguishing HGG from LGG,and there was a close correlation between the two parameters（r=0.959,p<0.001）.Conclusion:1.The ADC,D,D * and their relative values in the tumor area of IVIM parameters can effectively distinguish the high and low grades of adult diffuse gliomas.The true diffusion coefficient has a good correlation with the traditional apparent diffusion coefficient,and the diagnostic performance of the former is better than that of the latter.The diffusion effect reflected by IVIM is closer to reality than DWI.2.The role of peritumoral edema area f1 in distinguishing high and low grade adult diffuse gliomas needs further study;and the IVIM parameters of ADC1,D1,D*1 in the peritumoral edema area and the mirror side control area had no obvious effect on the grading of adult diffuse glioma.3.IVIM has the advantage of noninvasive quantitative reflection of water molecule diffusion and perfusion information of adult diffuse glioma,which can effectively distinguish high and low grade adult diffuse glioma,and provide a reliable basis for clinical preoperative diagnosis and classification,having a good application prospect.