磁共振波谱在星形细胞肿瘤恶性度分级中的价值

Significance of MR Spectroscopy in the Classification of Intracranial Astrocytic Tumors

目的:评估磁共振波谱对星形细胞肿瘤恶性程度分级中的意义。方法:51例星形细胞肿瘤患者,其中男性34例,女性17例,平均年龄43岁,进行磁共振常规和波谱检查,波谱检查选择PRESS序列,对波谱代谢物Cho、NAA、Cr和Lip进行评估。结果:术后病理证实:51例星形细胞肿瘤中,低度恶性(WHOⅡ级)24例,高度恶性(WHOⅢ-Ⅳ级)27例(3例间变性星形细胞瘤、24例胶质母细胞瘤)。Lip峰作为恶性标志,未见于低度恶性星形细胞肿瘤,见于26(26/27)例高度恶性星形细胞肿瘤,两组之间差异显著,Lip/Cr在间变性星形细胞瘤和胶质母细胞瘤(1.132±0.195vs2.014±0.196)之间亦差异有统计学意义(P≤0.05);Cho峰作为肿瘤细胞密度的标志,Cho/Cr在WHOⅡ、Ⅲ、Ⅳ级星形细胞肿瘤分别为1.912±0.086、3.002±0.522、4.095±0.320,差异有统计学意义(P≤0.01);Cr峰作为波谱代谢物的内标,在高度恶性肿瘤中明显减低,可能也反映了肿瘤的恶性变化。结论:Lip峰与Cho峰是星形细胞肿瘤术前分级有意义的生物学标志。

Purpose： To evaluate the significance of MR spectroscopy in pre - operational grading of intracranial astrocytic tumors. Methods： ^1H - magnetic resonance spectroscopy （MRS） using a point resolved spectroscopy （TR/TE 1000/144 ms） sequences were performed on 51 patients on a 3.0 T scanner. The metabolite of MRS, such as choline, N - acetyl - aspartate, creatine, and lipid, was evaluated. Results： The post operation pathology validated 24 cases of low - grade astrocytic tumors and 27 cases of high - grade astrocytic tumors. As a malignant biomarker, lipid peak was not identified in low - grade astrocytic tumors, whereas verified in almost all cases of high- grade astrocytic tumors （26/27）. Also, statistical difference of Lip/Cr was noted between anaplastic astrocytoma and glioblastoma（ P ≤ 0.05）. With choline signal indicating the density of tumor cell, Cho/ Cr was 1. 912 ± 0.086, 3.002 ±0.522, 4.095 ± 0.320 in astocytoma, anaplastic astrocytoma and glioblastoma respectively. Significant difference can be obtained among them. Considered as an internal standard, creatine peak decreased remarkably in high- grade astrocytic tumors. Conclusion： Lipid and choline signal may be significant biomarkers in the pre - operational classification of intracranial astrocytic tumors.