轻型创伤性脑损伤脑白质纤维束扩散张量成像研究

目的：使用3.0T 磁共振扩散张量成像(DTI)技术观察轻型创伤性脑损伤(mTBI)患者脑白质纤维束的改变,探讨 DTI对 mTBI 的临床诊断价值。方法选取30例 mTBI 患者及30例健康对照者分别进行常规 CT、MRI 及 DTI 检查,分别测量 mTBI患者(急性期、亚急性期、伤后5周~3个月)和对照者的胼胝体膝部、压部、双侧内囊前后肢、扣带束、上纵束、下纵束的各向异性(FA)值、表观扩散系数(ADC)值,观察各测量值的变化规律。结果mTBI 患者部分脑白质纤维束区的 FA 值在急性期、亚急性期减低(P 均<0.05),伤后5周~3个月时仍低于对照者(P 均<0.05),但胼胝体膝部及压部的 FA 值在急性期不减低反而升高(P 均>0.05),此后呈逐渐减低趋势,并在外伤5周~3个月时略低于正常对照组,但差异无统计学意义(P 均>0.05)。急性期、亚急性期 mTBI 患者的 ADC 值低于正常对照组,并在外伤5周~3个月时接近或略高于对照组,但差异无统计学意义(P 均>0.05)。结论DTI 对 mTBI 敏感性较高,能够准确显示白质纤维束的损伤情况并使其可视化,DTI 对 mTBI 的诊断具有重要的临床价值。

Diffusion tensor imaging for evaluating white matter fiber tracts in patients with mild traumatic brain injury

Objective To study the changes of white matter fiber tracts in mild traumatic brain injury(mTBI)patients by using DTI technique on 3.0T MR system,and evaluate the clinical diagnostic value of DTI.Methods Thirty mTBI and 30 matched health-y controls underwent conventional CT,MRI and DTI examinations.FA values and ADC values in the genu of the corpus callosum, the splenium of the corpus callosum,bilateral internal capsule,the cingulum bundle,the bilateral superior longitudinal fasciculus and the inferior longitudinal fasciculus of mTBI were measured in mTBI patients and controls at acute phase,subacute phase,5 weeks and 3 months post-trauma.The temporal changes of MRI data were observed.Results The FA values in the part of the white mat-ter fiber tracts reduced in the acute and subacute phase in mTBI patients (all P <0.05)in relative to controls (all P <0.05),At 5 weeks and 3 months post-trauma,the FA values also slightly lower in patients than controls.As for the genu of the corpus callosum and the splenium of the corpus callosum,the FA values in mTBI patients increased slightly at the acute stage (all P >0.05),but de-creased at 5 weeks-3 months post-trauma phase,though there was no significantly difference(all P >0.05).ADC values significantly decreased in the acute and subacute phase in mTBI patients,while they recovered thereafter (all P >0.05).Conclusion The sensi-tivity of DTI in detecting the lesions of mild traumatic brain damage is high,and it can display the damage of white matter.DTI could play an important role in the diagnosis of mTBI.