脑高级别星形细胞瘤瘤周DTI参数的测定及分析

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。

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

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.