脑高级别星形细胞瘤瘤周DTI参数的测定及分析

Measurements and analyses of high grade astrocytoma peritumoral parenchyma by using diffusion tensor imaging

目的:应用弥散张量成像(DTI)技术探讨脑高级别星形细胞瘤瘤周弥散各向异性特点。方法:25例脑高级别星形细胞瘤术前行DTI扫描,测定瘤周脑实质区及对侧正常脑实质的平均弥散系数(MD)值及各向异性分数(FA)值。并通过弥散张量纤维束成像(DTT)观察病灶与白质纤维束的关系。结果:高级别星形细胞瘤瘤周MD值为1.610±0.23,高于对侧正常脑实质(P<0.01)。FA值为0.236±0.06,低于对侧正常脑实质(P<0.01)。结论:DTI能够准确反应脑星形细胞瘤瘤周各向异性特点,DTT能够较为准确显示病灶与白质纤维束的关系。

Objective： To explore the diffusion anisotropic feature of peritumoral parenchyma by using magnetic resonance diffusion tensor imaging.Methods：25 patients with high-grade astrocytoma were enrolled in this study. Brain tissues were examined pathologically to confirm the intracranial diseases. DTT measurements were obtained from regions of interest （ROI） placed on peri-tumor and cerebral parenchyma of the normal side. Diffusion tensor tractography was reconstructed that diaplay the encountered patterns of tumor-related alteration to cerebral white matter. Results： On DTI, The peritumoral parenchyrna were all depicted as hyperintense or isointense signals on DTI. The difference of FA values between the peri-tumor and cerebral parenchyma of the normal side was significant （ P 〈 0.01）. Furthermore, diffusion tensor tractography can gave a quick and intuitive overview of the displaced course of white matter tracts in three-dimensional space. Conclusion： DTI can precisely determine the diffusion anisotropie properties of different intraeerebral tissues and can well display intracerebral neurofibers, providing a new functional examination for the clinical study of hlgh-grade astrocytoma.