Diagnostic Value Of ～1H-MR Spectroscopy In The Brain Astrocytomas

Objective To evaluate ~1H MR spectroscopic pattern of brain astrocytomas and to report characteristic spectral patterns that may be helpful in grading astrocytomas.Methods 26 cases of astrocytomas with pathologic confirmation underwent routine MRI, enhanced and ~1H MR spectroscopy examination. They were divided into three groups: 12 patients of low-grade astrocytoma (LGA) , 7 patients of anaplastic astrocytoma (AA) and 7 patients of glioblastoma multiforme (GBM). N-acetylaspartate (NAA), Choline (Cho), Creatine (Cr), Lactate (Lac) and my-Inosine (ml) values were measured in the regions of enhancement, necrosis , edema, and corresponding normal brain. A corresponding the NAA/Cr,Cho/Cr and NAA/Cho ratios were obtained from both the regions of enhancement, necrosis , edema, and corresponding normal brain of each group and that of among three groups.Results We observed decreased NAA and increased Cho in the region of enhancement. While Lac signal was detected in 22 patients and mI signal was detected in 24 patients. In the regions of enhancement, necrosis and edema, the NAA/Cr , NAA/Cho and Cho/Cr ratios changed significantly by comparing with that of normal control of brain tissue. A significant difference also existed the Cho/Cr ratios for in the region of enhancement among the three groups of astrocytoma (P<0.05) , but no significant different existed the NAA/Cr , NAA/Cho, mI and Lac of three groups (P>0.05) . A significant difference only existed the Lac for in the region of necrosis between LGA and GBM group (P<0.05). No significant different existed the other ratios in the region of necrosis among the three groups of astrocytoma (P>0.05) .A significant different existed the Cho/Cr ratios in the region of edema among the three groups (P<0.05) . No significant different existed the other ratios in the region of among the three groups of astrocytoma (P>0.05) .Conclusion It is characteristic that decreased NAA/Cr, NAA/Cho ratios and increased Cho/Cr ratio in the region of enhancement. The mean values of region of enhancement for LGA, AA and GBM were 1.97, 4.01 and 2.21 for Cho/Cr ratio. The mean values of region of necrosis for LGA, AA and GBM were 1.18, 2.60 and 3.95 for Lac value. The mean values of region of edema for LGA, AA and GBM were 1.05, 1.73 and 1.35 for Cho/Cr ratio. The ratios are helpful...