MRI体外定量测定SPIO标记兔骨髓间充质干细胞

MRI Quantitatively Measurement of SPIO-Labeled Mesenchymal Stem Cells in Experimental Rabbits in Vitro

目的测定MRI监测SPIO标记兔骨髓间充质干细胞(r-MSC)的最低SPIO浓度,寻找MRI体外定量测定SPIO标记r-MSC的方法。方法分离、培养r-MSC,不同浓度SPIO标记r-MSC 24 h后采用3.0 T MRI T2*WGRE、T1W-GRE、T2W-PROPELLER序列扫描标本。结果 3种序列中,T2*W-GRE序列体外监测SPIO标记干细胞的能力最佳,1×105/ml、1×106/ml细胞浓度下,T2*W-GRE序列测定的平均MR信号衰减率(△SI)与SPIO浓度之间具有强相关。结论适宜细胞浓度下,T2*W-GRE序列可用于定量近似预测SPIO标记浓度。

Objective To determine the lowest SPIO concentration necessary for MRI monitoring of SPIO-labeled mesenchymal stem cells （r-MSC） in experimental rabbits, and to find out the method for MRI quantitative measurement of r- MSC in vitro. Methods The r-MSC were purified by adherent culture and amplified in vitro. The r-MSC labeled with different concentrations of SPIO was incubated for 24 hour. 3.0 T MR scanning by using T2 ＊ W-GRE, T1W-GRE and T2W-PROPELLER sequences were used to scan these specimens. Results Among the three sequences, T2 ＊ W-GRE sequence was the best sequence in monitoring the SPIO labeled r-MSC. In the situation of cell concentration of 1×10^5/ml and 1 ×10^6/ml, the average MR signal attenuation rate （ASI） hail a close correlation with SPIO concentration. Conclusion In the situation of appropriate cell concentration, i.e. cell concentration of 1×10^5/ml and 1 x 106/ml, T2 ＊ W-GRE sequence can be used to quantitatively measure the approximately SPIO eoncentration.