颈髓弥散张量成像在肌萎缩性侧索硬化诊断中的应用

Cervical diffusion tensor imaging for diagnosis of amyotrophic lateral sclerosis

目的初步探讨颈髓弥散张量成像（DTI）在肌萎缩性侧索硬化（ALS）诊断中的应用价值。方法选择自2000年1月至2007年1月中山大学附属第二医院骨科收治的28例ALS患者为患者组，20例同期门诊查体健康成年人为对照组，对2组成员进行常规MRI扫描及DTI检查，获取颈髓MD值及FA值的直方图，并对ALS患者颈髓DTI弥散张量值与患者ALS残损功能评分量表（ALSFRS）评分进行相关性分析。结果与对照组相比，患者组颈髓FA值和颈髓横断面积明显降低，差异有统计学意义（P〈0．05）；MD值轻微增加，差异无统计学意义（P〉0．05）。患者颈髓FA值与ALSFRS评分高度相关（r=0．730，P=0．000），与MD值等指标无相关关系。结论ALS患者颈髓DTI显像FA值显著降低，FA值可能成为ALS诊断中的神经影像学阳性支持指标；颈髓的弥散张量值与ALSFRS结合，可以更全面反映ALS患者的病情进展。

Objective To investigate the application of cervical diffusion tensor imaging （DTI） in the diagnosis of amyotrophic lateral sclerosis （ALS）. Methods Cervical DTI and conventional magnetic resonance imaging （MRI） was performed in 28 ALS patients rated with ALS functional rating scale （ALSFRS） and 20 healthy control subjects to obtain the mean diffusivity （MD） and fractional anisotropy （FA） histograms of the cervical spinal cord. Correlation analysis between DTI of the cervical spinal cord and the ALSFRS scores of the ALS patients was conducted. Results Compared with the control subjects, the ALS patients had significantly lowered mean FA and reduced cross-sectional area of the cervical spinal cord （P〈0.05）, but the MD value did not differ significantly between the two groups （P〉0.05）. A close correlation was found between the mean FA of the cervical spinal cord and the ALSFRS score （r=0.730,P=0.000）, but not between the MD value and the ALSFRS score in the ALS patients. Conclusion Patients with ALS have significantly lowered mean FA, which may serve as an indicator for the diagnosis of ALS. Together with the ALSFRS score, cervical DTI can better characterize the progression of ALS.