Objective:To discuss the value of 1H-MRS for the histological grading of astrocytoma before surgery,by using different quantitative patterns (relative quantitative pattern and standardization pattern).Methods:In 16 cases of grade Ⅰ～Ⅱand 20 cases of grade Ⅲ～Ⅳ astrocytoma proved by surgery and histology,the ratio of different metabolic material including Cho/Cr,Cho/NAA,NAA/Cr,Cho/Cho (n,contralateral normal-appearing white matter,CNWM) for the necrotic component,solid component of the tumor,peripheral area (1.0～2.0cm) of tumor,CNWM as well as the standardized value of NAA,Cho,Cr were calculated.Results:There was significant difference between Cho/Cr,Cho/NAA,NAA/Cr,NAA/S,Cho/S of solid component of tumor,peripheral area of tumor and CNWM,as well as between Cr/S of solid component and CNWM.Significant difference also existed between Cho/Cr,NAA/S of solid component and peripheral area as well as Cho/NAA,Cho/S of solid component for grade Ⅰ～Ⅱ and grade Ⅲ～Ⅳ astrocytoma.Lac and Lip can be depicted in astrocytoma by 1H-MRS.Conclusion:Spectroscopy finding of astrocytoma is different from that of normal brain tissue.Tumor can be identified by using 1H-MRS.Tumor grading of malignancy was correlated with Cho/Cr,NAA/S of solid component and peripheral area of tumor,as well as Cho/NAA,Cho/S of solid component.State of hypoxia can be assessed by Lac,and Lip was an assisted marker to assess the malignant grading of tumor.There were both advantages and disadvantages of the two 1H-MRS quantitative patterns used,combination of the two provides more reliable information for diagnosis.
