3.0T磁共振扩散张量成像在腰椎间盘突出诊治中的应用

Application of MR diffusion tensor imaging in diagnosis of lumbar disc herniation

目的探讨3.0T磁共振扩张量成像(DTI)在椎间盘突出中的应用。方法回顾30例腰椎间盘突出患者和30例健康志愿者的磁共振平扫和DTI资料,测量两组L_3~S_1双侧神经根的表现扩散系数(ADC)、部分各向异性(FA)及纤维来示踪成像(DTT)显示神经根走行情况,比较椎间盘突出患者受压神经根与非受压神经根、健康志愿者正常神经根ADC值、FA值的差异。结果健康志愿者正常神经根及腰椎间盘突出患者受压神经根与非受压神经根的ADC值、FA值分别为(2.248±0.048)×10^(-3)mm^2/s、(2.751±0.052)×10^(-3)mm^2/s、(2.255±0.044)×10^(-3)mm^2/s和0.207±0.015、0.178±0.019、0.209±0.011。受压神经根的ADC值明显高于非受压神经根和正常神经根,差异均有统计学意义(均P<0.01),而受压神经根的平均FA值明显低于非受压神经根和正常神经根,差异均有统计学意义(均P<0.01)。DTT清晰显示神经根正常走行及受压改变。结论 3.0T磁共振DTI技术ADC值、FA值在腰椎间盘突出致神经根受压时有明显改变,DTT技术能够直观多方位显示神经根走行,对临床诊断和术前定位有指导意义。

Objective To assess the application of MRI diffusion tensor imaging （DTI） in diagnosis of lumbar disc herniation. Methods MR examination and DTI were performed in 30 patients of lumbar disc herniation and 30 healthy volunteers. The mean fractional anisotropy （FA） and apparent diffusion coefficient （ADC） values of L3, L4, L5 and S1 nerves in both sides were calculated by DTI, and these nerves were observed by diffusion tensor tractography （DTT）. Results The ADC and FA value of the normal spinal nerve roots in healthy volunteers and those of the compressed and uncompressed spinal nerve roots in patients were （2.248 ±0.048） × 10^-3 mm^2/s, （2.751 ±0.052）× 10-a mm2/s, （2.255 ± 0.044） × 10^-3 mm^2/s and 0.207 ± 0.015, 0.178± 0.019, 0.209 ±0.011. The ADC values of the compressed spinal nerve roots were significantly lower, and the FA values were significantly higher than those of the uncompressed and normal spinal nerve roots（P〈0.01）. Conclusion The ADC and FA values at MR DTI of the compressed spinal nerve roots are significantly changed in patients with lumbar disc herniation. The lumbar plexus nerve roots can be visualized clearly by using D-Fr, and it may helpful in preoperative localization of the lesions.