【摘要】 目的:研究超顺磁性氧化铁(superparamagnetic iron oxide,SPIO)对周围质子的弛豫时间的影响,探讨不同颗粒、浓度SPIO的MR信号特征。方法:对不同粒径及浓度的SPIO颗粒进行磁共振扫描,记录各个粒径和浓度的SPIO颗粒的MR T1、T2、T2*值,评价其信号特征。结果:①不同粒径的SPIO颗粒T1值与浓度呈负相关线性关系;②当SPIO浓度较低时,随粒径减小T2和T2*值则上升明显;当SPIO浓度较高时,随粒径减小上升渐趋缓慢;③lg(T2)与SPIO颗粒粒径和浓度之间存在线性依存关系。结论:SPIO颗粒对MR信号的影响以T1和T2效应为主;T2值可作为SPIO颗粒MR成像的主要检测指标;SPIO粒径大小、浓度和T2值三者之间存在着特定的线性关系。更多还原

【Abstract】 Objective: To investigate the magnetic resonance(MR) signal features of superparamagnetic iron oxide(SPIO) with different partical size and concentration.Methods: The superparamagnetic iron oxide with different concentration and particle size was scanned by magnetic resonance;T1,T2 and T2* values of each group were recorded to evaluate the features of MR signals.Results: The T1 value of SPIO with different particle size had negative linear relationship with concentration.In low concentration the T2 and T2* values were elevated markedly with the particle size decreased;while in high concentration the T2 and T2* values were elevated gently with particle size decreased.lg(T2),particle size and concentration of SPIO had linear relationship.Conclusions: SPIO affects magnetic resonance signal mainly with effect on T1 and T2.T2 value can be regarded as the major detection index in the magnetic resonance scan of SPIO.There is a linear relationship among particle size,SPIO concentration and lg(T2) value.更多还原