3T磁敏感加权成像对正常人脑深部灰质核团铁含量与年龄的相关性研究

目的：应用磁敏感加权成像（magnetic susceptibility weightedimaging，MSWI）技术，测定正常人脑深部灰质核团相位值，了解脑内铁分布规律，并分析其与年龄的相关性。方法：健康志愿者75名，按年龄分为3组：青年组（≤40岁）、中年组（41～60岁）和老年组（〉60岁），均行头部常规MRI序列及SWI序列扫描。在相位图上分别测量壳核、苍白球、尾状核、丘脑、黑质及红核的相位值。比较健康志愿者各脑深部灰质核团的不同年龄组间平均相位值的差异，并分析各灰质核团相位值与年龄的相关性。结果：各脑深部灰质核团的平均相位值与实际脑铁含量参考值呈负相关（r=0．849，P=0．032），即铁含量越多相位值越小。壳核、尾状核、黑质及红核的不同年龄组间平均相位的差异具有统计学意义（P值分别为0．000、0．003、0．001、0．003），丘脑、苍白球的不同年龄组问平均相位值的差异无统计学意义（P值分别为0．571、0．476）。壳核、尾状核、黑质及红核的相位值与年龄呈负相关（r值分别为0．706、0．403、O．356、0．257），苍白球、丘脑的相位值与年龄无相关性（r值分别为0．075、0．152）。结论：本研究加深了对脑深部灰质核团铁分布规律及其与年龄相关性的认识，为神经退行性病变的临床预测和早期诊断提供了一定的参考价值。

Application of 3T Magnetic Susceptibility Weighted Imaging in Study on the Correlation Between Iron Content of Brain Deep Gray Matter and Age

Objective To measure the phase values of brain deep gray matter of healthy subjects by using magnetic susceptibility weighted imaging（MSWI）, and to analyze its associativity with age. Methods In total, 75 healthy volunteers were enrolled. All were undergone conventional magnetic resonance imaging （MRI） and MSWI sequence scanning. Subjects were divided into three groups according to their ages： youth group（≤ 40 years old）, middle aged group （41-60 years old） and aged group （〉60 years old）. The phase values and iron deposition were quantified by using phase images in putamen （PUT）, globus pallidum（GP）, caudate nucleus （CN）, substantia nigra （SN）, red nucleus （RN）, and thalamus（THA）. Analysis of variance（ANOVA） software was applied to analyze the statistical differences among the different age groups. Linear regression analysis was used to further analyze the relationship between the phase values of deep gray matter and age. Results The phase values in PUT, CN, SN and RN among three age groups were statistically different （P〈 0.05）. Negative correlations between the phase values and age were shown in PUT, CN, SN and RN（P〈0.05）. Conclusion The results increased the understanding about brain iron distribution and its associativity with age, and provided a certain reference value for the clinical prediction and early diagnosis of neurodegenerative diseases.