Correlation study of T2 signal values of deep brain gray nucleus and age at 3.0T magnetic resonance imaging

Objective To study the correlation of T2 signal values of deep brain gray nucleus(including nucleus dentatus,red nucleus,substantia nigra,thalamencephalon,globus pallidus,putamen,caudate nucleus) and age at 3.0T magnetic resonance imaging.Methods T2W images were obtained in 1192 cases with normal brain MRIs using 3.0T Siemens Trio scanner in Beijing Tiantan hospital from Feb,2004 to Apr,2005(689 males,503 females,age range from 1 to 87 years).All the cases were divided into 17 groups by every five years.The signal values of nucleus dentatus,red nucleus,substantia nigra, thalamencephalon,globus pallidus,putamen,caudate nucleus and the frontal contex on T2WI were measured by using Efilm workstation 2.0 measuring tools.The measurements were conducted three times with variable oval areas.The rates of T2 signal values of deep brain gray nucleus by the frontal cortex were calculated.Results The analysis of variance revealed the anatomic location and the age group influence the ratio(P0.01,R squared=0.946).The ratioes of deep brain gray nucleus(except nucleus dentatus) have cubic curve equations with age groups,the equation is R=b_0+b_1x+b_2x~2+b_3x~3,where x stands for age group(range from 1 to 17),b_0 stands for constant,b_1,b_2 and b_3 stand for coefficients of the cubic curve equation.The respective R squares were 0.646,0.847,0.856,0.911,0.873 and 0.778.Conclusion The accumulation of iron depends on age and structures.From the data,we observed(age ranged from 1 to 87 years),in descending order of iron contents,the first group including substantia nigra,red nucleus,globus pallidus and nucleus dentatus have the highest iron contents;then the second group,consisting of putamen and thalamencephalon;the third group is caudate nucleus.