Brain Astrocytoma:3D Multivoxel~1H-MRS In Preoperative Grading And Pathological Findings

ObjectiveThis study was designed to approach the characteritics of astrocytoma3D Multi-voxel1H-MRS and the correlation with grading diagnosis in preoperative grading by analyzing the contents changes of major metabolites such as NAA Cho Cr Lac and Lip in astrocytoma’H-MRS, and jointly measuring ratio changes of NAA/Cr, NAA/Cho, Cho/Cr, Lac/Cr.Method45patients of brain astrocytoma which were confirmed by postoperative pathological results were gathered in the Second Affiliated hospital of Zhejiang University School of Medicine from JAN.2009to MAR.2014.29cases of male patients and16cases of female patients were contained, aged10-65years old(on an average45years);First symptoms:44cases of headache and dizzy,20cases of limb weakness,13cases of epilepsy seizure; The shortest course of disease was5hours, and the longest was3years;17cases of low-grade astrocytoma (Ⅰ-Ⅱ grade),28cases of high-grade astrocytoma (Ⅲ-Ⅳ grade),normal brain tissue of opposite side of tumor was set as internal control. The patients had no radiotherapy, chemotherapy and surgery history.First of all, all patients were conventionally scanned by3.0T magnetic resonance imaging system before surgery, and then3D Multi-voxel1H-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 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, Lac/Cr ratio were computed.Results:The mainly manifestation of brain astrocytoma3D Multi-voxel1H-MRS are NAA significantly lower, Cho significantly increased, Cr stable or slightly lower or slightly increased.3Cases emerged Lac among17cases of low-grade astrocytoma;12cases emerged Lac and11cases emerged Lip among28cases of high-grade astrocytoma; There were significant differences in NAA/Cho, Cho/Cr, NAA/Cr between solid area of astrocytoma and normal-area of opposite side (P<0.05); There were significant differences in NAA/Cho、NAA/Cr in solid area of astrocytoma between low-grade astrocytoma group and high-grade astrocytoma group (P<0.05), There were significant differences in NAA/Cho、NAA/Cr in peritumoral edema area between low-grade astrocytoma group and high-grade astrocytoma group (P<0.05), Cho/Cr (r=0.420)of solid area of tumor was of positive correlation with the grade of tumor, and NAA/Cr, NAA/Cho (r=-0.502,-0.542)was of negative correlation. Conclusion3D Multi-voxel1H-MRS contributes to the clinical diagnosis of brain astrocytoma, There were significant differences in NAA/Cho, Cho/Cr, NAA/Cr between solid area of astrocytoma and normal-area of opposite side and significant differences in NAA/Cr, NAA/Cho in solid area of astrocytoma between low-grade astrocytoma group and high-grade astrocytoma group and significant differences in NAA/Cr, NAA/Cho in peritumoral edema area between low-grade astrocytoma group and high-grade astrocytoma group. The values of chemical composition ratio of tumor was correlation with the grade of tumor. can provide quantify diagnosis basis for grading of brain astrocytoma before surgery, to sum up, has significance clinical application value.