摘要
磁共振成像(MRI)体模已成为评价成像质量的一种必不可少的工具。理想的体模材料应该是其质子密度、T1和T2值与人体组织的应尽可能接近;能分别调节Tl、T2;具有长久稳定性及简便的制作工艺。作者以聚乙烯醇(PVA)为基质,先后制备了一系列含有Co2+、Ni2+、Cu2+、Gd3+、C等添加剂的PVA凝胶作为体模材料。摸索了在实验室制备PVA体模材料的条件。在20MHz和80MHz的核磁共振波谱仪上测量T1、T2驰豫时间。研究结果表明:(1)顺磁性离子能缩短PVA凝胶的T1、T2值。其中以Gd3+的作用最大。(2)活性炭能单独地缩短PVA凝胶的T2值,而对T1值作用甚微。(3)乙醇作为辅助性溶剂能消除PVA凝胶中的气泡,提高材料的均匀度,而对T1、T2值没有多大的影响。(4)在不同的共振频率下测定PVA凝胶的T1、T2,有较大的差别。
The MRI phantom has become a necessary tool of evaluating image quality,Ideal phantom materials should at least have the following characteristics :their proton densi-ty and T1,T2 values should be close to those of human tissues, T1 and T2 values can be adjust-ed respectively, and they should be steady and simple in preparation. The phantom materialshave been made by adopting PVA gel with different additives as Co2+,Ni2+,Cu2+,Gd3+ andC. We also have measured T1,T2 relaxation time by MR spectroscopy(20MHz,80MHz). Theresult is:1)Paramagnetic ions can shorten Tl and T2 values of PVA gel,among which Gd3+has the most powerful effects; 2)Active carbon can shorten T2 values of PVA gel,while T1value still remains the same;3)Alcohol as a supplementary solution can eliminate the air bub-bles in the PVA gel and improve the material homogeneity,but not basically affect Tl and T2values;4)Difference of T1 and T2 will be obtained by MR measuring under the different fre-quencies.
出处
《中国医学物理学杂志》
CSCD
1995年第3期147-149,共3页
Chinese Journal of Medical Physics
基金
国家自然科学基金