7.0T磁敏感加权成像对脑铁含量测定的初步研究

Preliminary study of brain iron concentration measured with susceptibility weighted imaging in 7.0T MR

目的:对比7.0T与3.0T磁敏感加权成像铁含量测量的差异,并积累超高场磁共振神经成像经验。方法:50例老年志愿者(年龄52～68岁,男36例,女14例)分别在7.0T和3.0T磁共振成像系统上行常规颅脑磁共振成像及磁敏感加权成像(SWI)。对比不同场强下的图像质量,测量受试者双侧苍白球、壳核、尾状核头、黑质、红核以及丘脑的大小及相位值,同时测量受试者各核团铁含量。结果:①幅度图上,7.0T影像能提供更多细节,并可区分核团亚分区(P<0.05);②7.0T下可辨识的ROI范围较3.0T下的略大,不同场强的各核团ROI范围差异有统计学意义(P<0.05);③除苍白球外,壳核、尾状核头、黑质、红核及丘脑3.0T和7.0T比较,铁含量测量值差异均有统计学意义(P<0.05)。结论:7.0T磁共振磁敏感成像可提供更多解剖细节,SWI脑铁含量测量值与3.0T可能存在差异。

Objective：To investigate iron concentration measurement difference in susceptibility weighted imaging between 7.0T and 3.0T MR and to describe an initial experience for ultra-high field neuroimaging. Methods： 50 gerontic volunteers （aged 52~68y, M 36,F 14） underwent conventional brain MRI and SWI on 3.0T and 7.0T scanner respectively. Compare the image quality under different magnetic field was compared and the bilateral size and phase value of globus pallidus （GP）, putamen （PUT）, head of caudate nucleus （HCN）, substantia nigra （SN）, red nucleus （RN） and thalamus （THA） were measured. Results：①7.0T could provide more details in magnitude images including recognition of sub-nucleus （P〈0. 0001）. ②The areas of nucleus regions of interest were slightly larger in 7.0T than in 3.0T, and the difference was statistically significant within same position of slices;③Significant difference in iron concentration were found in PUT, HCN, SN,RN and THA between 3.0T and 7.0T except in GP. Conclusion：①Images in 7.0 Tesla can provide more details in structure; ②Iron Concentration might be different in measurement with 7.0T SWI.