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

Objective To analysis the correlation and change regulation between the mean value of ADC,FA,T_2W 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),T_2 weighted MR imaging,T_1 weighted MR imaging and diffusion tensor imaging of the lumbar spine were performed, an isotropic ADC map,FA map,b0 map and b400 map was calculated from DTI,then calculate the mean value of ADC,FA,T_2W signal intensity and analysis the change regulation of ADC,FA,T_2W 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(r1=-0.668,p0.001,r2=-0.683,p0.01,r3=-0.622,p0.001,r4=-0.540,p0.001),the value of FA and T_2W 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,p0.05),but the ADC value of L3/4-L5/S1 intervertebral discs was not correlated with anatomic location(r=-0.048,p0.05).The FA value(r=0. 349,p0.001) and T_2W signal intensity(r=0.658,p0.001) 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,relatively s table phase and slowly decreased phase.The ADC value and FA value could be more reflect the change of water diffuse mode than T_2W 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.