磁共振波谱和扩散张量成像对多发性硬化的诊断价值

Clinical application of magnetic resonance spectroscopy and diffusion tensor imaging in multiple sclerosis

目的:探讨MRI的磁共振波谱和扩散张量成像在多发性硬化(MS)诊断中的应用,并分析较优参数。方法:对32例MS患者和32名健康志愿者(健康对照组)进行头部磁共振波谱和扩散张量成像扫描,分别选取患者的脱髓鞘斑块、表现正常的脑白质(NAWM)区域和对照组相应区域测量氮-乙酰天门冬氨酸(NAA)/肌酸(Cr)比值、胆碱(Cho)/Cr比值、表观扩散系数(ADC)值和部分各向异性(FA)值,并绘制ROC曲线,分别计算其ROC曲线下的面积。结果:在脱髓鞘斑块的ROC曲线图中,NAA/Cr、Cho/Cr、ADC和FA曲线下的面积分别为0.938、0.843、0.975和0.952,提示ADC值是诊断脱髓鞘斑块的最优参数;在NAWM的ROC曲线图中,上述4条曲线下的面积分别为0.722、0.692、0.691和0.657,提示NAA/Cr比值是诊断NAWM存在异常的最优参数。结论:同时应用磁共振波谱和扩散张量成像检查并定量测量其参数值,可以全面评价MS的脱髓鞘斑块和NAWM异常,将会对临床制定治疗方案和判断预后有重要的参考作用。

Objective： To choose the best MRI index that can evaluate multiple sclerosis （MS）patients＇ plaque and normal-appearing white matter（NAWM） regions, using magnetic resonance spectroscopy（MRS） and diffusion tensor imaging（DTI）. Methods： MRS and DTI examinations were performed in 32 patients with MS and in 32 age-matched control subjects. N-acetylaspartate（ NAA）/Creatine （Cr） ratios, Cho/Cr ratios, Apparent diffusion coefficient （ADC） values and Fractional anisotropy （FA） values in MS plaques, NAWM regions and the same regions in control subjects were measured. Receiver operating characteristic （ROC） curves were drawn. The areas below ROC curves were calculated respectively. Results： In ROC curves of MS plaques, the areas of NAA/Cr, Cho/Cr, ADC and FA were 0. 938, 0. 843, 0. 975 and 0. 952, respectively, indicating ADC was the best index for diagnosing MS plaques. In ROC curves of NAWM regions, the areas of NAA/Cr, Cho/Cr, ADC and FA were 0. 722, 0. 692, 0. 691 and 0. 657, respectively, indicating NAA/Cr was the best index for diagnosing abnormality of NAWM. Conclusion： MS plaque and NAWM can be fully evaluated by applying both MRS and DTI examinations to measure the parameters. These will be an important reference for clinical treatment and prognosis judgment.