扩散张量成像和三维脑白质束示踪在多发性硬化中的临床应用

Diffusion tensor imaging and three-dimensional brain fiber tracking for the diagnosis of multiple sclerosis

目的探讨多发性硬化(MS)患者的 MS 斑块、斑块旁脑白质和 T_2WI 上表现为正常的脑白质区(NAWM)的扩散张量成像(DTI)特点,并探讨 DTI 和三维脑白质束示踪技术对 MS 的应用价值。方法对32例 MS 患者和32名与 MS 患者年龄性别配对的正常人进行头部 DTI 检查,生成表观扩散系数图(ADC)和部分各向异性图(FA),分别选取 MS 斑块、斑块旁脑白质区、NAWM 区和对照组正常人相应脑白质区测量 ADC 值和 FA 值,并使用示踪技术做出三维脑白质束图像。结果 MS斑块、斑块旁脑白质区、NAWM 区和对照组的 ADC 平均值分别为(1.233±0.119)、(0.973±0.098)、(0.748±0.089)×10^(-3)mm^2/s 和(0.620±0.094)×10^(-3)mm^2/s,FA 平均值分别为0.225±0.052、0.311±0.050、0.421±0.070和0.476±0.069。对 MS 斑块、斑块旁脑白质、NAWM 数据进行随机区组方差分析最小显著差法检验,差异有统计学意义(P<0.01)。MS 斑块、斑块旁脑白质、NAWM 分别和对照组配对t检验,差异有统计学意义(P<0.01)。用三维脑白质束图像可以观察到 MS 斑块。结论使用 DTI 检查生成的 ADC 图和 FA 图可以有助于评价 MS 中各部位脑白质的改变。通过三维脑白质束示踪图像可以立体直观地显示 MS 斑块区白质束的异常。

Objective To demonstrate the diffusion tensor imaging （DTI） characteristics of multiple sclerosis （MS） plaques, periplaque white matter regions and normal appearing white matter （NAWM） regions in patients with MS, and to evaluate the clinical values of DTI and three-dimensional brain fiber tracking for the diagnosis of MS. Methods Conventional MRI and DTI were performed in 32 patients with MS and 32 age-matched control subjects. Fractional anisotropy （FA） and apparent diffusion coefficient （ADC） maps were generated and coregistered with T2-weighted MR images. FA and ADC values were calculated in regions of interest in plaques, periplaque white matter regions, NAWM regions and white matter regions in control subjects. And three-dimensional brain fiber tracking maps were generated by using theDTI. Results The ADC was （1. 233±0.119）×10^-3 mm^2/s in MS plaques, （0.973±0.098） ×10^-3 mm^2/s in periplaque white matter regions, （0.748 ＋0.089） ×10^-3 mm^2/s in NAWM, and （0.620 ± 0.094） ×10^-3 mm^2/s in control subjects. The FA was 0.225 ±0.052 in MS plaques, 0.311 ±0.050 in periplaque white matter regions, 0. 421 ± 0. 070 in NAWM, and 0. 476 ± 0. 069 in control subjects. Significant differences in FA and ADC values were observed among all white matter regions （P 〈 0. 01 ）. MS plaques were demonstrated in three-dimensional brain fiber tracking maps. Conclusion FA and ADC maps are helpful for the evaluation of all white matter changes of MS. The abnormalities of white matter fiber tracts in MS plaques could be demonstrated in three-dimensional brain fiber tracking maps.