| Objective Parkinson's disease(PD) is the most commonneurodegenerative disease come on old adults, with its main pathological changes located at the neostriatum. Diffusion tensor imaging is a newly developed magnetic resonance technology, and is sensitive for detecting abnormal changes in the white matter. Our study is to quantify the values of fractional anisotropy(FA) and eigenvalues(A) using diffusion tensor imaging in the putamen and globus pallidus respectively, which are the two main structure of the neostriatum, and to investigate their relationship with aging. The results of this study are also used asstandard comparison to our further diffusion tensor research in PD. Methods Sixty nine normal volunteers (38men, 31women; age range, 20-80; mean age, 41.6) with normal results in the conventional MR examination were recruited, and divided into three groups according age( group one: <30 years, 22 volunteers, mean age: 25.6±2.4; group two: 30-50 years, 24 volunteers, mean age: 40.1±6.4; group three: >50years, 23 volunteers, mean age: 58.6±7.8). The values of ADC, FA, λ1, λ2 and λ3 in putamen and globus pallidus were calculated after diffusion tensor scanning, and then analyzed the differences between the two tissues with two-group t-test. The differences of ADC, FA, λ1, λ2 and λ3 values between agegroups and their relationship with age were also studied. Results Between thecorrespondent age groups, the value of FA in the putamen(0.20±0.03, 0.23±0.03, 0.25±0.03) was lower than that in the globus pallidus(0.35±0.03, 0.36±0.03, 0.37±0.04), and the ADC value was higher in the putamen(6.68±0.40, 6.47±0.36, 6.41 ±0.36) than that in the golbus pallidus(6.13±0.50, 6.05±0.33, 6.02±0.52), which showed significant difference with t-test statistical analysis (P=0.000) .Eigenvalue λ1 in the putamen(8.03±0.36, 7.93±0.30, 7.99±0.28) was lower than that in the globus pallidus(8.31±0.55 8.23±0.32 8.23±0.48), while eigenvalue λ2(6.48±0.78 6.41±0.37 6.36±0.35) and λ3(5.35±0.46, 5.04±0.46, 4.9±0.44) were larger than them in the globus pallidus, which values were 5.93±0.83 , 5.97±0.34 5.97±0.52 and 3.98±0.51 , 3.90±0.37 , 3.80±0.71 respectively. The FA value in the putamen was significantly elevated with aging(r =0.555, p=0.000), while the FA value in the globus pallidus was well preserved(r =0.213, p=0.084) with advancing age. Eigenvalue λ3 in the putamen showed age-related decline(r=-0.472, p=0.000). ANOVA statistical analysis of the FA value between age groups also revealed there were significant differences in theputamen, but not in the globus pallidus. Conclusion The putamen and globuspallidus are parts of the basal ganglia and consist of both the grey matter and fiber. The values of ADC FA and eigenvalues in the putamen and globus pallidus shows the diffusion pattern in the putamen is significantly different to that in the globus pallidus, but both reflect well the characteristic of fine structure in the putamen and globus pallidus respectively. The phenomenon of age-related elevation of the FA value lie in the putamen, not in the whole lenticular nclei, and λ3 in the putamen show age-related decline. When the diffusion tensor imaging of lenticular nclei is used in studying neurodegenerative diseases, such as PD, it is necessary to differentiate diffusion patterns in the putamen and globus pallidus, and because some diffusion parameters show age correlation in some degrees, the age factor is also be concerned.
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