Clinical Evaluation Of Magnetic Resonance Multi Modality Imaging In The Diagnosis And Grading Of Gliomas

Background and PurposeCancer is a serious threat to human life and health of cancer. WHO (world healthorganization, WHO) statistics show that the incidence rate showed an increasing trendand predict the number of cancer deaths worldwide in2030will reach13.1million,so cancer is a serious problem twenty-first century global human health. Glioma(brain glioma, BG) is the most common primary tumor of the central nervous system,originated in the glial cells, accounting for as much as half of all intracranial tumors.According to the WHO classification of tumors, the international standardclassification in2007, Categories include glioma: astrocytoma, oligodendrogliomacell tumors, ependymoma, subependymal tumor, medulloblastoma, and choroidplexus tumors, et al. in which the most common astrocytoma. Grading of gliomagrade Ⅰ~Ⅳ.Ⅰ~Ⅱ stage is a low-grade gliomas, Ⅲ~Ⅳ grade high-grade gliomas;benign gradeⅠ, Ⅲ~Ⅳ grade malignant, Ⅱgrade tumor is benign and borderline evil.Clinically, most patients with glioma performance lack of specificity. Headache,dizziness is a common manifestation of its early existence can often be overlooked;With the extension of the course,15%to95%of patients with sudden seizures; Whenalready have the basic characteristics of the tumor, the disease often have is late, soaccurate and timely diagnosis is the key to early brain glioma treatment.However, to date, surgical resection is still the main choice of the way the clinical treatment of glioma, grade gliomas are not the same, treatment is verydifferent. Survival time of patients with low tumor levels are closely related: patientswith low-grade gliomas5-year survival of about80%in patients with high-gradeglioma survival time is significantly shorter than the low-grade gliomas, especially ingrade IV tumors5-year survival of patients is often less than5%, Ⅲgrade gliomas inbetween, And their clinical course and treatment planning are great difference, suchas: astrocytomas often only need operation excision, plus radiotherapy can, withoutchemotherapy plan; as well as anaplastic astrocytoma, due to its strong infiltration,operation is not easy to clean cut, high recurrence rate, so need radiotherapycombined with chemotherapy, to prolong the survival time of patients, so the brainglioma is timely and accurate diagnosis and staging is a prerequisite for treatment.With magnetic resonance (magnetic resonance imaging, MRI) research anddevelopment progress of computer hardware and software, imaging and scanningsequence of a new generation emerge in an endless stream, MRI functional imagingmainly include: diffusion weighted imaging (diffusion weighted imaging, DWI), thediffusion tensor imaging (diffusion tensor imaging, DTI), the perfusion functionimaging (perffusion weighted imaging, PWI), and spectroscopic imaging (magneticresonance spectroscopy, MRS), and magnetic susceptibility weighted imaging(susceptibility weighted imaging, SWI), the blood oxygen level dependent functionalmagnetic resonance imaging (blood oxygen level-dependent functional magneticresonance imaging, Bold-fMRI), The above functional magnetic resonance imagingcombines anatomical features, functions and images of three aspects of the law on theexploration of the tumor cells or molecular level, the research and development ofdrugs, the formation of modern medical modality and improving the level of theultimate ideal of human health target has far-reaching significance, so in the widerclinical application.At present, the brain glioma examination is still mainly rely on imagingtechnology, but, so far, magnetic resonance imaging of any single mode are notenough to fully show the structure, function and molecular tumor information, specifyeach modal tests have their unconquerable limitations, so the combined use ofmultimodal magnetic resonance imaging technology to reach each other complementary advantages, mutual authentication purposes, fully reflect the brainglioma structure, function and molecular information and so on, has become the focusof research and development of contemporary imaging.In this study, the routine MRI plain scan and enhanced scan, DTI and1H-MRSthree kinds of imaging methods, through the signal characteristics, analysis of brainglioma plain scan and enhancement of the solid part of tumor and peritumoral edemain the apparent diffusion coefficient (average diffusion coefficient, ADC) value, therelative apparent diffusion coefficient (relative average diffusion coefficient, rADC),fractional anisotropy (fractional anisotropy, FA) value, the relative fractionalanisotropy (relative fractional anisotropy, rFA) and1H-MRS value showed that themain metabolite ratios (Cho/Cr, NAA/Cr, NAA/Cho, MI/Cr) and other parameters,And a preliminary study of the correlation between diagnosis and grading of gliomawith plain and enhanced signal characteristics, rADC value, rFA value and themetabolite ratios on glioma, in order to achieve in the premise of as much as possibleto protect the normal brain tissue, the greatest degree of resection of the tumor,improve life quality, prolong life time. Therefore, MRI scan and multi-modalinformation to enhance the anatomy, function and molecular aspects of informationglioma scans, DTI and1H-MRS provided for glioma treatment options and prognosisprecise design has a major the clinical significance.Part1：Evaluation of magnetic resonance DTI and DTT in thediagnosis and grading of gliomasObjective:1. The subject in the conventional plain and enhanced MRI scans basis, usingdiffusion tensor imaging methods, analysis of glioma tumor, peritumoral edemarelative apparent diffusion coefficient (rADC) value, relative fractional anisotropy thediagnostic value (rFA) values, etc., and to explore rADC value, rFA values, et al, aswell as correlation with pathological grade.2. Analysis DTT at different levels glioma and white matter fiber tracts, and toexplore the diagnostic value of DTT, and the correlation with the histological grade. 3. Through analysis of the body and the peritumoral edema brain gliomas formaking clinical treatment plan to provide more, anatomy and function morereasonable diagnosis information.Methods:1. From2010October~2013year in October period in patients with cerebralglioma and72cases with complete data as the research object. All the patients werenot as radiotherapy, chemotherapy and other anti-tumor therapy, the clinical surgery,histopathology confirmed glioma,21cases in which low-grade glioma (grade Ⅰ4cases,Ⅱ17cases), high grade gliomas51cases (Ⅲg rade20cases, grade Ⅳ31cases).47males and25females, aged2to67years, with an average age of45years old.2. The patients were using the U.S. GE Signa HD3.0T superconducting MRscanner and an8-channel phased-array head coil, using multi-sequence, multi-faceted,multi-parameter imaging. And in accordance with the principles of MRI safety, andsigned informed consent.3. The patients were swept in MRI scans foundation level and enhanced uplinkDTI inspection, DTI using single-shot spin-echo-echo planar (SSE-EPI) imagingsequence, DTI line axial scanning parameters: diffusion gradient field to take15different directions. This paper focuses on measuring a substantial part of the tumor,edema and contralateral white matter ratio of peritumoral been relatively FA (rFA)and relative ADC (rADC) method to reduce errors.4. Diffusion tensor tractography using continuous tracking method, selection ofperitumoral adjacent and contralateral fiber bundle as the seed region, thresholdsetting for FA is0.18, cerebral white matter fiber bundle evaluation standard, thedomestic general practical standards are divided into three basic forms: the shiftchange, infiltration and sabotage.5. All the data were statistically analyzed by SPSS15software. All the measureddata by the mean±standard deviation（x s）said, statistical methods includingindependent samples t test, paired t test and two sets of ordered variable data ranksum test. To test the level of a=0.05, P<0.05had significant difference.6. Surgical resection specimens were fixed in10%neutral formalin, embedded in paraffin, continuous4um thickness sections were observed by HE staining,histological grade according to the2007edition of the WHO InternationalClassification of brain tumors and grading standards.Results:1. Into high-grade gliomas and low-grade gliomas two groups,21cases oflow-grade glioma (grade Ⅰ4cases, Ⅱ17cases),51cases of high-grade gliomas (Ⅲgrade20cases, Ⅳgrade31cases).2. Unenhanced and enhanced MRI scans showed the presence of conventionalMRI examination can lesions, different levels of brain glioma, each signalcharacteristics.3. The FA chart shows: fiber bundle changes, by9cases, no decrease signal;infiltration in41cases, FA value decreased, reducing signal part; failure in22cases,the signal decreased obviously. The ADC chart shows: of the45cases showedslightly high signal or uneven high signal,17cases showed isointensity or low signal,10cases showed slightly low signal; peritumoral edema in66cases showed high orslightly high signal,6cases had no obvious edema with a signal;28cases of cysticnecrosis was high signal.4. Glioma group comparison: To compare the differences between high, lowgrade gliomas tumor, peritumoral edema with rFA value, there was no statisticalsignificance (P>0.05). High, low grade glioma tumor, peritumoral edema withdifference in rADC value, were statistically significant (P <0.05).5. Glioma group comparison: high, low level of tumor rFA values were less thanthe other peritumoral edema with rFA value, the difference was statisticallysignificant (P <0.05). High, low level of tumor rADC values were less than the otherperitumoral edema zone, the difference was statistically significant (P <0.05).Conclusion:1. Conventional MRI scanning combined with DTI is effective image gliomadiagnosis and classification of science. 2. High, low grade glioma group tumor region, peritumoral edema with nosignificant difference between rFA values; but the high, low grade gliomas, the samelevel of tumor rFA value is less than the other peritumoral edema with rFA value, thedifference has statistical significance.3. High, low grade glioma group tumor region, peritumoral edema with rADChad significant difference with tumor grade, and the higher the lower the rADC value,i.e, negative correlation.4. DTT and FA maps clearly shows the relationship between the tumor andsurrounding white matter fiber bundles, for the location of its main functional areas ofwhite matter fiber tracts, can directly observe the changes in the white matter fiberbundle morphology, to develop precise solutions for the treatment of glioma, Themaximum range can safely remove the tumor and reduce postoperative morbidity. Part Ⅱ：Evaluation of magnetic resonance1H-MRS in the diagnosisand grading of gliomasObjective:1. Based on the uplink1H-MRS scan before a group of patients (5cases withoutscanning or remove unsuccessful scan patients). The1H-MRS imaging of brainglioma, tumor, peritumoral edema zone and contralateral numerical aspects of brainwhite matter of Cho, NAA/Cho, NAA/Cr, Cho/Cr, MI/Cr, qualitative and quantitativeanalysis, and to explore the diagnostic value of various numerical, and correlationwith pathological grading.2. Combined with routine MRI scan, reflect the microcosmic substancemetabolism of brain glioma from cellular or molecular level, and statistical analysis,in order to enhance the peritumoral tissue invasion of1H-MRS glioma diagnosis andclassification accuracy and the judgment of tumor.3. To use a variety of mode MRI to improve the accuracy of magnetic resonance imaging diagnosis, and provide objective evidence for clinical diagnosis, treatment ofscience.Methods:1. From2010October~2013year in October during the complete data of67patients with cerebral glioma as research object, inclusion and exclusion criteria werethe same as group1. Among the20cases of low grade gliomas (4cases,16cases ofgrade II),47cases of high grade gliomas (18cases in grade Ⅲ,29patients with gradeIV). Male43cases, female24cases, age2~67years old, the average age is44.6years old.2. The patients were using the U.S. GE Signa HD3.0T superconducting MRscanner and an8-channel phased-array head coil, safety principles and the principlesof medical ethics with the former group.3. This group of patients were in plain and enhanced MRI scan based uplink1H-MRS scan,1H-MRS examination using single voxel (SV) point resolvedspectroscopy analysis (PRESS) and chemical shift selective saturation pulse (CHESS)water suppression method. Imaging time3’48", water suppressed <98%wavelength,<5bandwidth. In the T2WI sequence selective lesions axial maximum diameter of thelevel as the region of interest (VOI) of the center, SV MRS.4. Correction of spectral analysis application of machine’s software phase andthe baseline, area and calculate the peak; according to the chemical displacement ofthe peak area of each compound corresponding, to estimate the concentration of thecompound; analysis of peak value and the ratio of each compound.5. SPSS15software was used for statistical analysis of data. The experimentalresults are the mean standard deviation（x s）said, different grades of glioma Cho,NAA/Cr, Cho/Cr, NAA/Cho, MI/Cr ratio were compared using independent samplest test; High, low grade glioma group within the Cho, NAA/Cr, Cho/Cr, NAA/Cho,MI/Cr ratio compared with paired t test; high, low grade gliomas high, low gradeglioma Lac peak, Lip peak were compared using chi square test. Tumor rADCmeasured glioma tumor Cho/Cr ratio and the first part of the value correlationanalysis. To test the level of a=0.05, P<0.05had significant difference. 6. Determine the pathological results with a group.Results:1. Into high-grade gliomas and low-grade gliomas two groups,20cases oflow-grade glioma (grade Ⅰ4cases, Ⅱ16cases),47cases of high-grade gliomas (Ⅲgrade18cases, Ⅳgrade29cases).2. Unenhanced and enhanced MRI scans showed the presence of conventionalMRI examination can lesions, different levels of brain glioma, each signalcharacteristics.3. Gliomas1H-MRS features: Cho peak has increased to varying degrees, thehigher the level, the more obvious rise; NAA peak decreased, Cr peak is relativelystable, MI peaks rise; Cho/Cr ratio increased; NAA/Cr, NAA/Cho ratio decreased,Lip peak seen only in high-grade gliomas, Lac peak height, low-grade gliomas mayoccur.4. Between the two groups: the ratio between a high, Cho low-grade gliomatumor area and the same level of contralateral white matter areas, Cho/Cr, NAA/Cr,NAA/Cho, the differences were statistically significant (P <0.05). High and low gradegliomas the tumor area metabolites: comparison between Cho,NAA/Cr,Cho/Cr,NAA/Cho, MI/Cr ratios, the differences were statistically significant (P <0.05).Glioma tumor and peritumoral edema area of Cho, the ratio between Cho/Cr, NAA/Cr, NAA/Cho, differences were statistically significant (P <0.05).5. Within group comparisons:Ⅰ~Ⅱ peritumoral edema zone with the tumor arearatio between Cho, Cho/Cr, NAA/Cr, NAA/Cho, the differences were statisticallysignificant (P <0.05). The ratio between III~IV glioma edema zone, the tumor Cho,Cho/Cr, NAA/Cr, NAA/Cho, the differences were statistically significant (P <0.05).6. The body region glioma NAA/Cr, NAA/Cho ratio and the pathological gradeswere negatively correlated (correlation coefficient rs=-0.429,-0.414; P <0.01), theratio of Cho/Cr was positively related with pathological grade (correlation coefficientrs=0.741, P <0.01).7. High, low grade gliomas were visible Lac peak, has nothing to do with thepathological grades of glioma. The Lip peak is only found in senior don’t brain gliomas, Lip peak has significance in differential high, low grade gliomas.8. Correlation analysis was carried out with the first part of the content, Cho/Crratio and rADC value of the correlation coefficient is-0.739and-0.712, there exists anegative correlation of Cho/Cr ratio and rADC value of glioma tumor and peritumoraledema area.Conclusion:1.1H-MRS is an effective supplementary technique for the diagnosis of glioma.2. Combined with routine MRI scan,1H-MRS can improve the accuracy ofdiagnosis of brain glioma.3.1H-MRS can be more accurate evaluation of glioma grading, reflect themicrocosmic substance metabolism information of brain glioma from cellular ormolecular level.4.1H-MRS can observe the microcosmic substance metabolism glioma tumor,peritumoral edema zone, especially an earlier forecast the invasion of peritumoraledema zone.