The Study On Clinical Application Of Brain Gliomas Grading With ~1H-MRS

Objective: Glioma is the most common primary tumors in central nerv -ous system,account for 35.26%-60.96%(on an average 44.69%)of intracranial tumors. Glioma grows invasively,whose pathogenesis is not be completely clarified.The routine CT and MRI examination can only make preliminary judging on the location,size and shape of brain tumors,yet clinicians often hope to get more comprehensive and accurate information about preoperative qualitation and tumor grading and range.It is of great importance for clinical surgery and postoperative comprehensive treatment, and it can help clinicians to work out appropriate surgery and treatment plans. Magnetic resonace spectroscopy(MRS) was first used in the medical field in 1973.MRS can quantitatively measure metabolites concentration in vivo tissue selectively and noninvasively, moreover it has higher detection sensitivity,it judges contents of specific chemical substances by analyzing different resonance frequency peak in the coordinates,and then provides more reliable information for grading gliomas in clinic. At the present time,atomic nucleus such as 31P 1H 23Na 13C 19F 7Li can be used in MRS study of medical fields.Due to the higher natural abundance and atomic magnetic inductive of 1H than other atomic nucleus in the organic structure, 1H is most used in the study of magnetic resonace spectroscopy. The proton magnetic resonace spectroscopy(1H-MRS) can be used to detect a variety of minute quantity metabolites,such as N-acetylaspartate(NAA),Choline(Cho),Creatine(Cr),Lactate(Lac), Lipids(Lip), Myoinosital(MI),γ-Aminobutyric Acid(GABA),Glutamic acid(Glu), Glutamine(Gln) and Taurine,etal. At the present time, 1H-MRS is more mature in the study of brain tumors especially gliomas.This study was designed to approach the characteritics of gliomas 1H-MRS and the correlation with grading diagnosis by analyzing the contents changes of major metabolites such as NAA Cho Cr Lac and Lip in glioma 1H-MRS,and jointly measuring ratio changes of NAA/Cr, NAA/Cho,Cho/ Cr.Methods: 33 patients of brain glioma which were confirmed by postoperative pathological results were gathered in The Second Hospital Of HeBei Medical University from Sep.2009 to Aug.2010,18 cases of male patients and 15 cases of female patients were contained,aged 9-60 years old(on an average 44.3 years);First symptoms: 23 cases of headache and dizzy,7 cases of limb weakness,3 cases of epilepsy seizure;The shortest course of disease was 2.5 hours,and the longest was 10 years;14 cases of low-grade gliomas(ⅠandⅡ),19 cases of high-grade gliomas(ⅢandⅣ), normal brain tissue of opposite side of tumor was set as internal contral.The patients had no radiotherapy,chemotherapy and surgery history.First of all,all patients were conventionally scanned by 3.0T magnetic resonance imaging system before surgery,and then 1H-MRS examination were taken.Region of interest(ROI) were separately located in solid area of tumors,peritumoral edema area and contralateral normal area.The signals were collected by point resolved spectroscopy analysis.The initial data gathered from MRS were sent to ADW4.2 workstation for post-processing,then the peak area values of chemical composition such as NAA Cho Cr Lac and Lip were obtained,at last NAA/ Cr,NAA/ Cho,Cho/ Cr ratio were computed.Pathological diagnosis: 33 patients of brain glioma were all treated by surgery in Neurosurgery of The Second Hospital Of HeBei Medical University,the tumor specimens were removed and instantly fixed in the Formalin solution,then were sent to Pathology department in the hospital,HE stainings were taken after paraffin embedding and slicing.The pathological grade of gliomas were defined by senior chief doctor of Pathology department according to WHO grading standards(2000).Statistical methods:at first,the average values of the ratio of metabolites in three different regions of gliomas were computed,the results were stated with X±S ,then the data was input SPSS 13.0 statistical package,to adopt One-Way Anova,it is statistically significant among groups if P <0.05.Thereby we can futher study the differences in metabolites between gliomas and normal brain tissue,and the differences in metabolites between low-grade gliomas and high-grade gliomas.Results:The mainly manifestation of brain gliomas 1H-MRS are NAA significantly lower,Cho significantly increased,Cr slightly lower. There were significant differences in NAA/ Cr,Cho/NAA,Cho/ Cr between solid area of glioma and normal-area of opposite side(0.79±0.42,2.63±0.79,2.00±0.48;1.42±0.31,0.63±0.07,0.90±0.19)(P<0.05);There were significant differences in NAA/ Cr,Cho/NAA,Cho/ Cr in the solid area between the low-grade glioma group and the high-grade glioma group(0.92±0.47,1.81±0.53,1.55±0.32; 0.74±0.26,3.24±1.07,2.41±0.92)(P<0.05);There were significant differences in Cho/NAA,Cho/Cr in peritumoral edema area between low-grade glioma group and high-grade glioma group(1.21±0.38, 1.13±0.29 ; 2.14±0.63, 2.27±0.26)(P<0.05).Conclusion: 1H-MRS contributes to the clinical diagnosis of brain gliomas,and can provide quantify diagnosis basis for grading of brain glioma before surgery,to sum up, has very significance clinical application value.