磁共振弥散张量成像在脑高级别星形细胞瘤和转移瘤瘤周实质区的诊断价值

目的 探讨磁共振弥散张量成像(diffusion tensor imaging,DTI)在高级别星形细胞瘤和单发脑转移瘤诊断中的价值.方法 25例脑高级别星形细胞瘤和16例单发脑转移瘤,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,并重建白质纤维示踪图,观察病灶与白质纤维束的关系.结果 高级别星形细胞瘤与脑转移瘤瘤周实质区的FA值分别为0.227±0.05、0.169±0.07,两者存在统计学差异(P＜0.05).DTI白质纤维示踪图可以较为准确地反映病灶与白质纤维束的关系.结论瘤周实质区FA值有助于高级别脑星形细胞瘤与转移瘤的鉴别.

Peritumoral Diffusion Tensor Imaging of High Grade Astrocytoma and Metastasis

Objective To study the value and clinical significance of diffusion tensor imaging(DTI)in differentiating high-grade astrocytomas and solitary metastatic tumors of brain.Methods 16 patients with intracranial solitary metastasis and 25 patients with high-grade astrocytoma confirmed pathologically were examined with MR DTI.Mean diffusivity(MD)and fractional anisotropy(FA)were measured in the regions of interest(ROI)of peritumor and cerebral parenchyma of the normal side on DTL Fiber tractography was reconstructed and the encountered patterns of tumor-related alteration to cerebral white matter were observed.Results The peritumor were all depicted as hyperintense or isointense signals on DTI.The FA values were 0.227±0.05 and 0.169±0.07 in the peritumor of high-grade astrocytoma and metastasis respectively,which was of significant difference(P＜0.05).Furthermore,fiber tractography could display the course of white matter tracts in three-dimensional space.Conclusion DTI may be help to differential diagnosis of solitary metastasis and high-grade astrocytoma in clinical practice.