MRI和MR扩散张量成像在肌萎缩侧索硬化症中的价值

Applied value of MRI and MR diffusion tensor imaging in diagnosis of amyotrophic dateral sclerosis

目的探讨常规MRI检查和MR扩散张量成像(DTI)新技术在肌萎缩侧索硬化症(ALS)中的临床应用价值。方法对16例ALS患者(病例组)和15例健康志愿者(对照组)行常规MRI检查和DTI扫描,观察锥体束走行区的信号特点,并选取感兴趣区测量各向异性分数(FA)和平均扩散系数(ADC),分析2组间差别以及病例组各临床指标与FA、ADC值的相关性。结果在病例组中,8例双侧内囊后肢后3/4处呈高于皮层的局限性T2WI高信号;4例见双侧大脑脚、内囊后肢及侧脑室周围沿皮质脊髓束广泛分布的T2WI高信号影。在对照组中,16例双侧内囊后肢呈与皮层信号相等的局限性T2WI略高信号。在内囊后肢水平,病例组FA值明显低于对照组,ADC值明显高于对照组,P值均<0.05;在中央前回皮层下白质,病例组FA值有下降趋势;在中央前回皮层下白质和侧脑室周白质,ADC值有升高趋势。在半卵圆中心、大脑脚等锥体束走行区以及中央后回皮层下白质、额叶白质、胼胝体压部、膝部、丘脑等非锥体束走行区,两组间FA值和ADC值无统计学差异。病例组内囊后肢FA值与ALS功能评分正相关,与诊断确定性呈负相关,与年龄、病程、病情进展速度均无关;内囊后肢ADC值与各临床指标无相关性。结论ALS患者常规MR表现缺乏特异性,需结合临床综合判断。DTI新技术可客观而定量的评价锥体束病变,为ALS的诊断和预后判断提供有价值的信息。

Objective To explore the clinical value of MRI and MR diffusion tensor imaging （DTI） in amyotrophic lateral sclerosis（AKS）. Methods There 16 patients with El Escorial definite, probable, or probable - laboratory support ALS were studied, These patients were compared with 15 age and sex - matched normal controls （NC）. The two groups were all underwent a conventional MRI and DTI sequence on a 1 .ST MR system. For quantitative assessment of the fractional anisotropy （FA） and average diffusion coefficient （ADC） values of bilateral corticospinal tract regions and Non - corticospinal tract regions were measured on all 10 regions, and statistical analysis was performed. Correlation between diffusion parameters and various clinical variables were also investigated. Results Focal high signal intensity （hyperintense to gray matter） on T2WI was demonstrated in 8 ALS cases （53. 3% ） in bilateral posterior limb of internal capsule （PIC）. The extensive corticospinal tract high intensity on T2WI, including the periventricular white matter, the PIC, the cerebral peduncle, was detected in 4 AKS cases （26.7%）. In NC group, the focal slight high signal intensity （isointense to gray matter） on T2WI was demonstrated in all 16 subjects in bilateral PIC. A significant reduction in FA and increase in ADC was observed on the level of posterior limb of internal capsule in ALS group; There was a trend towards reduced FA and elevated ADC on the level of the subcortical white matter （SWM） of precentral gyrul in ALS group. Conclusion Clinical information must be considered when diagnosing ALS by using conventional MR imaging. The diffusion tensor MRI can noninvasively detect and assess corticospinal tracts and its potential disorder in vivo, thus providing useful information in diagnosing and further understanding ALS.