扩散加权成像在多发性硬化病灶和NAWM区中的研究

Studies of diffusion-weighted imaging in lesions and normal-appearing white matter areas of multiple sclerosis

目的:研究多发性硬化(Multiplesclerosis,MS)病灶、看似正常表现脑白质(Normal appearing white matter,NAWM)区与健康志愿者脑白质区表观扩散系数(Apparent diffusion coefficient,ADC)之间的差异,并探讨ADC值与扩展残疾状态量表(Expanded disability status scales,EDSS)之间的相关性。方法:对44例复发-缓解型多发性硬化(Relapsing-remitting MS,RRMS)患者和20例健康志愿者行头颅常规磁共振成像(Magnetic resonance imaging,MRI)和扩散加权成像(Diffusion weighted imaging,DWI)扫描,分别测量急性、慢性病灶、额叶NAWM区及健康志愿者额叶白质区的平均ADC值,比较其有无统计学差异,并分析病灶ADC值与EDSS评分之间的相关性。结果:(1)所有MS病灶、额叶NAWM区和健康志愿者额叶白质区各感兴趣区(Region ofinterest,ROI)的ADC值分别为(112.02±15.16)×10-5 mm2/s、(79.33±4.83)×10-5 mm2/s和(77.32±3.55)×10-5 mm2/s,三者间均有显著统计学意义(P<0.01);(2)急性和慢性病灶ADC值分别为(136.43±7.72)×10-5mm2/s和(110.66±3.45)×10-5 mm2/s,二者有显著统计学意义(P<0.01);(3)慢性病灶中,T1加权图像(T1-weighted images,T1WI)呈等信号和低信号病灶ADC值分别为(102.65±4.14)×10-5 mm2/s和(128.89±6.97)×10-5 mm2/s,二者有显著统计学意义(P<0.01)。(4)MS患者病灶ADC值与EDSS评分之间无显著相关性(P>0.05)。结论:通过DWI的定量指标ADC值有助于鉴别MS患者不同期相和不同信号病灶所发生的病理改变,并能检测NAWM区的隐匿性损害。

Objective：To study the differences of apparent diffusion coefficient（ADC） values among different lesions,normal-appearing white matter（NAWM） areas in multiple sclerosis（MS） and white matter areas in healthy volunteers,and to explore the correlation between ADC values and expanded disability status scale（EDSS） scores.Methods：44 patients with relapsing-remitting MS（RRMS） and 20 healthy volunteers underwent both conventional magnetic resonance imaging（MRI） and diffusion-weighted imaging（DWI） of brain.The mean ADC values were measured for the acute and chronic lesions,NAWM areas of MS patients and white matter areas of the controls,respectively.The statistical data were performed to determine the mean ADC value differences among various lesions of MS,and to analyze the correlation between ADC values of lesions and EDSS scores.Results：（1） The mean ADC values were（112.02±15.16）×10-5 mm2/s for all lesions,（79.33±4.83）×10-5 mm2/s for NAWM areas of MS,and（77.32±3.55）×10-5 mm2/s for white matter areas of the controls,respectively, there were significant differences（P0.01）.（2） The mean ADC of acute lesions （（136.43±7.72）×10-5 mm2/s） was significantly higher than that of chronic lesions（（110.66±3.45） ×10-5 mm2/s）（P0.01）.（3）In the chronic lesions,the ADC values of isointense lesions on T1-weighted images（T1WI） were lower than that of hypointense lesions（P0.01）,the ADC values were （102.65±4.14）×10-5 mm2/s and（128.89±6.97）×10-5 mm2/s,respectively.（4）No significant correlation was found between ADC values and EDSS scores（P0.05）.Conclusion：Quantitative ADC values are useful to identify the changes of pathology in different phases and signal lesions,and to detect the occult damage in the NAWM areas of MS patients.