Application Of DCE-MRI,3D-ASL And DSC-PWI In Preoperative Grading Diagnosis Of Glioma

Background and purpose Brain glioma（BG）is the first tumor originating from glial cells in the nerve epithelium,the most common brain primary malignant tumors,accounting for more than 50% of all intracranial tumors.BG can occur at any age,children mainly occur in the skull base and midline area,mostly hair cell astrocytoma and ependymoma;adults are more common hemispheric tumor,such as astrocytoma,Tumor,ependymoma and so on.The clinical manifestations of BG can be divided into two types of symptoms such as headache,nausea,vomiting and optic disc edema caused by increased intracranial pressure and limb movement disorders,hemianopia and epilepsy caused by neurological impairment.Different levels of BG treatment and clinical prognosis is very different,therefore,before surgery to accurately determine the pathological level of BG on the treatment of the design,surgical plan to determine the postoperative radiotherapy and chemotherapy measures to assess the prognosis of significant clinical significance The Routine examinations include computed tomography（CT）and magnetic resonance imaging（MRI）in the event of clinical symptoms.Head CT is only to determine whether there is an initial intracranial space,and MRI in displaying the characteristics and properties of BG is better than CT examination,so MRI has become the preferred method of evaluation of BG imaging and clinical recognition,and BG Preoperative accurate grading often relies only on conventional MRI exams that are often not enough.The degree of malignancy of the tumor is closely related to the microvessel structure and tumor cell proliferation.Therefore,it is important to evaluate the angiogenesis of BG in order to identify the degree of malignancy.Because BG has rich vascularity,its vascular structure and normal brain tissue vascular structure are significantly different,manifested in both the intrinsic cerebrovascular and neovascularization;BG new blood vessels with density,severe distortion and poor vascular diameter uniformity characteristics,Therefore,the degree of neovascularization is an important indicator of the degree of malignancy of BG,which provides a theoretical basis for the diagnosis,classification and differential diagnosis of BG by perfusion weighted imaging（PWI）.Based on the principle of tracer contrast agent,the current application of perfusion techniques are divided into: intravenous rapid injection of exogenous contrast agent,according to its longitudinal relaxation is the T1-weighted dynamic contrast enhancement(dynamic contrast-enhanced（DCE-MRI）and the effects of lateral relaxation on T₂ * / T₂-weighted dynamic susceptibility contrast（DSC）perfusion-weighted imaging（DSC-PWI）;no need for exogenous（ASL-PWI）technique with water proton as its own endogenous tracer.In this study,we compared the value of various parameters of DCE-MRI,DSC-PWI and 3D-ASL in BG pathological grading,and discussed the advantages and disadvantages of these three techniques.And pathological grading to provide new ideas.Materials and Methods 1 Subjects: Collected from the first Affiliated Hospital of Zhengzhou University from September 2015 to May 2016 period by conventional imaging examination found that patients with brain parenchymal lesions,starting,untreated,complete clinical data included in the study,all patients in the Before MRI examination,we have been informed of the condition and signed the MRI informed consent form,MRI examination ended 2 days to 7 days to accept the surgical treatment.Forty-eight patients with BG were confirmed.There were 45 cases of DCE-MRI scan and 37 cases of DSC-PWI scan.All patients underwent 3D-ASL scan.Postoperative pathology was graded according to 2016 WHO CNS new classification criteria.All patients were treated with neurosurgery in Zhengdayi Affiliated Hospital.The surgical specimens were identified by the two senior pathologists of the Department of Pathology.The grade Ⅰ and grade Ⅱ were low grade glioma（low grade glioma,LGG）,grade Ⅲ and grade Ⅳ were high grade glioma（high grade glioma,HGG）for 26 cases.Using Germany’s Siemens 3.0T Prasima superconducting magnetic resonance scanner and 64-channel dedicated head and neck joint dedicated coil and supporting special high-pressure syringe.MRI contrast agent for the gadopentetate leucine injection（Gd-DTPA）,trade name: Ma Genwei significant injection rate of 4ml / s.2 Method Scanning sequence: 1 routine MRI plain scan: T1 WI,T₂WI,T₂ flair axial,T1 WI sagittal,DWI;2 3D-ASL-PWI;3 DCE-MRI or DSC-PWI sequence check.（4）enhanced conventional T1 axis axis scan.3 Image Processing All the primitive perfusion data obtained was imported into the Siemens Syngo.via post-processing station and post-processed with MRI Perfusion software.By the three sub-high and above the senior magnetic resonance physicians were selected ROI,and then get the interest area of the quantitative value.4 Data Processing In this study,82 cases of BG patients with perfusion imaging data and data using SPSS 22.0 software package for statistical analysis,the experimental data using mean ± standard deviation（sx ±）,multi-group comparison of parameters using one-way analysis of variance,In both comparisons,the LSD-t（Least-Significant Difference）test was used.Finally,the optimal threshold of perfusion of HGG and LGG and the corresponding sensitivity,specificity and accuracy were obtained by statistical analysis of the receiver operating characteristic（ROC）curve to judge the corresponding diagnostic efficacy.Result 1.The mean Ktrans and Ve values of HGG were significantly higher in LG patients（P <0.01）than those in 45 patients with DCE-MRI.According to the univariate analysis of variance,the mean Ktrans and Ve values were significantly different between grade Ⅱ and grade Ⅲ,grade Ⅱ and grade Ⅳ（P <0.01）,while there was no obvious difference between grade Ⅲ and grade Ⅳ Statistical differences（P> 0.05）.2.In the 37 patients with DSC-PWI,the mean r CBV and r CBF of BG were significantly higher than those of low grade BG（P <0.01）.Univariate analysis of variance showed no significant difference in r CBV and r CBF between grade Ⅰ and grade Ⅱ（P> 0.05）.However,r CBV and r CBF were between grade II and III,Ⅳ,Ⅲ and Ⅳ There was significant statistical significance（P <0.01）.3.The average r CBV and r CBF of 37 patients with DSC-PWI were significantly higher than those of low grade BG（P<0.01）.The single factor variance analysis showed that r CBV and r CBF the difference between class I and II level was not statistically significant（P>0.05）,however,grade II and III,IV,III and IV between r CBV and r CBF was statistically significant（P<0.01）.4.In the 37 patients with both DSC and ASL,the relative blood flow perfusion index（TBFmax）,the contralateral hemisphere,contralateral white matter,and the CBF of the contralateral gray matter were not observed in the cerebral blood flow images of ASL and PWI perfusion imaging There was significant difference（P> 0.05）.5.Draw HGG and LGG value of Ktrans,Ve,r CBV,r CBF three ROC curves can be obtained four AUG are: 0.912,0.879,0.999,respectively.On the basis of Youden index,the optimal threshold can be obtained Ktrans,Ve,r CBV and r CBF in differential diagnosis of HGG and LGG were 0.059/min-1,0.357,2.152,2.11;according to the sensitivity and specificity of the threshold parameters HGG and LGG don’t opinion,each parameter identification sensitivity was 96.4%,93.7%,99.4% and 97.4% respectively;the specificity was 84.75%,73.2%,98.2%,95.2%.Conclusion 1.Three kinds of MRI perfusion techniques can accurately obtain the tumor blood vessel growth and hemodynamic changes in information on the preoperative pathological grading of BG has important value.2.The Ktrans value measured in the DCE-MRI technique can be used as a quantitative indicator for distinguishing BG levels.But there was no statistically significant difference between the two groups at grade Ⅲ and grade Ⅳ,which indicated that the vascular permeability of grade Ⅲ and grade Ⅳ was similar.3.The r CBV and r CBF values measured in the DSC-PWI technique are closely related to the BG level,which indicates that the r CBV and r CBF values can be used as a quantitative indicator for distinguishing BG levels.4.3D-ASL and DSC-PWI technology has the same perfusion effect,because ASL has low cost,fast,convenient,real-time imaging,no intravenous balloon contrast agent,can be repeated many times the advantages of non-invasive inspection,so 3D-ASL technique is worthy of promotion in preoperative classification of BG.5.When comparing the pathological grades of BG with different perfusion imaging parameters,it is found that r CBV is the most sensitive parameter for distinguishing between HGG and LGG.