正常人椎间盘MRI弥散张量成像ADC值、FA值与年龄和解剖部位的相关性研究

The Correlation between the MRI-DTI-ADC/FA Value and Age,Anatomic Location of Healthy Volunteers Lumbar Intervertebral Discs

目的探讨正常人椎间盘ADC值、FA值与年龄和解剖节段的相关性及其变化规律。方法募集健康志愿者45人,年龄范围6-40岁,6-10岁5人,11-15岁6人,16-20岁6人,21-25岁13人,26-30岁5人,31-35岁5人,36-40岁5人。进行常规T_2W、T_1W及DTI扫描,重建ADC图、FA图、b0图及b400图,测定其ADC值、FA值及T_2W信号强度,分析上述值随着年龄增加的变化规律。结果L1/2、L2/3、L3/4、L4/5椎间盘ADC值与年龄呈负相关(rB1B=-0.668,p<0.001,rB2B=-0.683,p<0.001,rB3B=-0.62 2,p<0.001,rB4B=-0.540,p<0.001),椎间盘FA值、T_2W信号强度与年龄不相关。随着年龄的增加,椎间盘的ADC呈下降趋势,5-15岁呈快降阶段,16-25岁相对稳定阶段,26-40岁缓降阶段。L1/2-L3/4椎间盘ADC值与解剖部位相关(r=0.279,p<0.05),从上到下ADC值逐渐升高,L3/4-L5/S1椎间盘ADC值与解剖部位无相关性(r=-0.048,p>0.05)。各椎间盘FA值(r=0.349,p<0.001)及T_2W信号强度(r=0.658,p<0.001)与解剖部位相关。结论正常人体椎间盘ADC值随着年龄增加呈下降趋势,FA值在L4/5-L5/S1椎间盘显著增大,ADC值及FA值比T_2W信号强度值更能体现椎间盘水分子弥散能力的变化,了解正常椎间盘ADC值及FA值随年龄的变化规律,有助于进一步理解椎间盘退变的发生机制。

Objective To analysis the correlation and change regulation between the mean value of ADC,FA,T2W signal intensity of intervertebral discs and age, anatomic location in healthy volunteers by diffusion tensor imaging. Methods The study population consisted of 45 healthy volunteers（range,6-40years）,T2 weighted MR imaging,T1 weighted MR imaging and diffusion tensor imaging of the lumbar spine were pertbrmed, an isotropic ADC map, FA map,b0 map and b400 map was calculated from DTI, then calculate the mean value of ADC,FA,T2W signal intensity and analysis the change regulation of ADC,FA,T2W signal intensity value with age increased. Results It indicated that the ADC value of L1/2,L2/3,L3/4,L4/5 intervertebral discs negatively correlated with age（rl =-0.668, p〈0.001, r2=-0.683, p〈0.001, r3=-0.622, p〈0.001, r4=-0.540, p 〈0.001）,the value of FA and T2W signal intensity were not correlated with age.The ADC value decrease with age increased, the ADC value decreased quickly from 5 to 15years, maintains a relatively stable value from 16 to 25 years, decreased slowly from 26 to 40years.The ADC value of L1/2-L3/4 intervertebral discs was positively correlated with anatomic location（r=0.279, p〈0.05）,but the ADC value ofL3/4-L5/SI intervertebral discs was not correlated with anatomic location（r=-0.048, p〉0.05）.The FA value（r=0. 349, p〈0.001） and T2W signal intensity（r=0.658, p〈0.001） were not correlated with anatomic location. Conclusion The mean ADC value of normal lumbar spine decrease with age increased, could be classified into three stage： quickly decreased phase, rela- tively stable phase and slowly decreased phase. The ADC value and FA value could be more reflect the change of water diffuse mode than T2W signal intensity,it is helpful to comprehend the mechanism of intervertebral discs degeneration via study the change regulation between the value of ADC,FA and age.