用作核磁共振造影增强剂的氧化铁溶液理化性质测定

Determination of physical and chemical properties of the iron oxide solution to be used as a contrast agent for NMR

为探讨大分子包埋氧化铁微粒溶液用作核磁共振造影增强剂的可能性 ,测定其铁含量、粘度、密度、分子大小、磁化率等理化性质 ;在核磁共振诊断仪上测定铁浓度随T1、T2信号强度的变化。结果表明 ,得到氧化铁微粒溶液的铁浓度为 8.5g/L ,用电镜测定的颗粒大小为 10nm ,粘度为0 .0 0 168Pa·s,当微粒溶液铁浓度为 0 .1mmol/L时 ,T2信号强度的下降大于 50 % ,T1信号强度在铁浓度为 0 .2— 0 .4mmol/L时 ,有一峰值 ,然后下降。溶液放置 1年 ,无大颗粒和明显沉淀物出现。说明本实验制备的葡聚糖包埋氧化铁溶液颗粒均匀 ,悬浮性好 ,在核磁共振诊断仪上显示出 ,随着铁浓度的增加 ,T2信号强度下降快 ,适于用作核磁共振造影的阴性增强剂。

The purpose of this article is to determine physical and chemical properties of the iron oxide solution prepared in our laboratory and to evaluate the possibility for using it as a nuclear magnetic resonance contrast agent. The iron concentration and viscosity of the solution were found to be 0.15 mol/L and 0.00168 Pa·s, respectively, the particle size of the iron core was about 10nm determined with a transmission electronic telescope. The susceptibility increased with increasing iron concentration. The T2 signal intensity decreased by more than 50% at iron concentration of 0.1mmol/L, there was a peak of T1 signal intensity at iron concentration of 0.2—0.4mmol/L. No precipitate was observed in the solution after storing for one year. It was concluded good homogeneity and suspensibility of the iron solution were obtained. The significant decrease of T2 signal intensity with iron concentration shows that the solution was a promising contrast agent for magnetic resonance imaging.