磁共振弥散张量成像对Wallerian变性诊断价值的评价

目的：探讨磁共振弥散张量成像技术（diffusion tensor imaging, DTI）在Wallerian变性中的诊断价值。方法:对40例正常志愿者、10例正常变异者和 40例病变者分别进行DTI和常规MRI扫描。结果：正常志愿者大脑脚、脑桥基底部皮质脊髓束走行区各向异性分数（fractional anisotropy, FA）均值分别为0.73和0.63，其FA比值（数值小的一侧比大的一侧）分别为97.6%和96.8%；正常变异者大脑脚、脑桥基底部皮质脊髓束走行区FA均值分别为0.72和0.64，其FA值比值分别为96%和95%，与正常志愿者相比，差异无统计学意义（P＞0.05）；病变者患侧大脑脚、脑桥基底部FA均值分别为0.64及0.52。其FA比值（患侧FA值比健侧FA值）分别为76.0%和77.0%，患侧大脑脚、脑桥基底部皮质脊髓束的FA值及其比值较正常者明显减小,差异有统计学意义（P＜0.05）。结论：DTI技术通过测量FA值及其比值及神经纤维束的三维重建，较常规MRI更为准确客观地诊断Wallerian变性。

Role of diffusion tensor imaging in diagnosing Wallerian degeneration

Objective: To explore the value of the diffusion tensor imaging(DTI) in diagnosing Wallerian degeneration.Methods: DTI and MRI protocols were performed on 40 healthy volunteers,10 normal variants and 40 patients,respectively.Results: The mean FA ratios of the corticospinal tracts in cerebral peduncle and basilar part of pons were 0.73(97.6%) and 0.63(96.8%) in 40 healthy volunteers,and they were 0.72(96.0%) and 0.64(95.0%) in 10 normal variants;No significant difference was found between the healthy volunteers and normal variants(P>0.05).Whereas,they were 0.64(77.0%) and 0.52(76.0%) in 40 patients,significantly reduced compared with the healthy volunteers and the normal variants(P<0.05).Conclusion: DTI is more accurate than MRI in diagnosing Wallerian degeneration.