弥散张量成像技术在星形细胞肿瘤中的应用价值初探

目的：评价MRI弥散张量成像技术在星形细胞肿瘤中的应用价值。材料和方法：采用GE1.5T超导MR成像系统，对16例1-2级星形细胞肿瘤及15例3-4级星形细胞肿瘤进行了MRI检查，检查序列包括T1WI、T2WI、FLAIR、弥散张量序列（diffusion tensor imaging，DTI）及增强后T1WI。结果：正常脑白质纤维在不同解剖平面，如半卵圆中心、内囊、胼胝体、视放射、锥体束、锥体交叉及内外侧丘系等，各向异性分数图（FA）均为高信号，白质纤维受到破坏后表现为低信号，而这些表现在常规T1WI、T2WI及FLAIR图上未能清楚显示。结论：DT1可以无创性检查脑白质纤维，用于脑肿瘤诊断及术前手术方案的制定。

Diffusion Tensor Imaging in the Evaluation of the Cerebral Astrocytic Tumors

Purpose: To evaluate the usefulness of diffusion tensor imaging in cerebral astrocytomas. Materials and Methods: Using a GE 1.5T super conduct MR unit, 16 grade 1-2 astrocytomas and 16 grade 3-4 astrocytomas underwent conventional MR imaging ,including T1WI,T2WI,FLAIR,diffusion tensor imaging and T1WI with intravenous contrast. Results:FA images depicted white matter features not typically seen on conventional MR images (e.g., external capsule,internal capsule,callus,pyramidal tract) .Fiber mapping images showed the ipsilateral pyramidal tract as either discontinuous due to impaired anisotropy or compressed due to mass effect in patients with brain tumors.Conclusion: Diffusion tensor imaging provides new information regarding the detailed relationship between tumor and nearby white matter tracts applicable as important information in planning brain tumor resection.