颅内肿瘤磁共振波谱谷氨酸/谷氨酰胺复合物定量研究

目的 评价氢质子磁共振频谱(¹H-MRS)定量检测谷氨酸复合物(Glx)浓度在颅内肿瘤定性诊断和分级诊断中的应用价值。 方法 采用GE 1.5T MRI系统,对38例颅内肿瘤患者(包括脑膜瘤、星形细胞瘤、脑转移瘤)及9名正常志愿者进行单体素¹H-MRS扫描,用LCModel软件定量Glx浓度。38例颅内肿瘤患者均经病理及临床证实。 结果 脑膜瘤Glx峰的出现率高于星形细胞瘤和脑转移瘤。脑膜瘤Glx浓度较正常脑组织、星形细胞瘤、脑转移瘤明显升高(P<0.05)。脑转移瘤与星形细胞瘤间Glx浓度的差异无统计学意义(P>0.05);脑转移瘤与高级星形细胞瘤间Glx浓度的差异也无统计学意义(P>0.05)。低级星形细胞瘤Glx浓度较高级星形细胞瘤高(P<0.05)。 结论 ¹H-MRS定量检测Glx浓度对脑膜瘤的定性诊断有重要的提示意义,对星形细胞瘤的分级诊断可能具有一定的意义,瘤体Glx定量无法鉴别脑原发肿瘤和脑转移瘤,瘤周水肿区Glx定量价值仍有待探索。

Glutamate complex quantification in intracranial tumors with magnetic resonance spectroscopy

Objective To investigate the value of glutamate complex (Glx) quantification in diagnosing and grading intracranial tumors with proton magnetic resonance spectroscopy (¹H-MRS). Methods Thirty-eight patients with intracranial tumors (including meningiomas, astrocytomas and metastases tumors) and nine healthy volunteers were examined with single-voxel ¹H-MRS. Glx concentrations were quantificated with LCModel software. Diagnoses of the patients were confirmed pathologically and clinically. Results The occurrence rate of Glx peak was higher in meningiomas compared with those in astrocytomas and metastases tumors. Glx concentrations presented higher in meningeomas than that in normal brain tissue, astrocytomas and metastases tumors (P<0.05). Glx concentrations neither showed significant difference between metastases and astrocytomas (P>0.05), nor between metastases tumors and high-grade astrocytomas (P>0.05). Compared with high-grade astrocytomas, Glx concentrations were higher in low-grade astrocytomas (P<0.05). Conclusion Quantification of Glx with ¹H-MRS shows a promising role in differentiating meningiomas from other intracranial tumors, and may be useful for grading astrocytomas. The value of Glx quantification in tumor masses can not help in discriminating primary brain tumors from metastases tumors. However, the value of Glx quantification in peritumoral edema is expected to explore.