中文摘要：

目的通过蛛网膜下腔置管，将超顺磁性氧化铁（SPIO）标记后的骨髓间充质干细胞（MSCs）移植入兔脊髓损伤模型，观察脊髓损伤MR活体示踪移植细胞的可行性。方法制作兔SCI模型，并在蛛网膜下腔置管以备移植。将实验用大白兔随机分为三组：A组为移植SPIO标记细胞；B组为移植未标记细胞；C组不移植细胞只注射PBS液做对照组。在细胞移植后3d、7d、14d、21d，进行MR活体示踪，并做病理学检测进行对照。结果SPIO标记的MSCs移植入脊髓损伤模型后7d，MR扫描的T2WI上脊髓损伤区域出现点状低信号影；14d后T2WI上脊髓损伤区域的点状低信号影增多，21d后T2WI上脊髓损伤区域的点状低信号影减少。脊髓损伤区域组织切片行普鲁士蓝染色，发现局部组织上出现大量含蓝色铁颗粒的细胞，其细胞变化规律与MR示踪结果一致。结论蛛网膜下腔移植的SPIO标记MSCs可定向迁移到脊髓损伤区域，利用MR可对移植细胞进行活体示踪。

英文摘要：

Objective Graft bone marrow mesenchymal stem cells labeled superparamagnetic iron oxide （SPIO） into the spinal cord injury models via subarachnoid space, to observe the feasibility of MRI tracking of grafted cells. Methods BMSCs were labeled with SPIO. Rabbit spinal cord injury models were made and the micro tubes were inserted into subarachnoid space. Rabbits were randomly divided into 3 group. Group A received SPIO labeled cells via subarachnoid spaces;Group B received unlabeled cells;Group C was injected by PBS liquid as the control group. Grafted BMSCs were tracked by Serial 1.5T MRI in 3,7,14 and 21 days after transplantation and compared with tissue slices of injured spinal cord. Results After BMSCs labeled with SPIO were grafted into the spinal cord injury, MRI test was performed at 7,14,21 days respectively. At 7 days, there appeared point-like low signal shadow in the injured spinal cord segment in T2WI;At 14 days, this low signal shadow increased;At 21 days, this shadow decreased. Cells containing blue iron particles in the area of spinal cord injury could be seen in tissue sections with Prussian blue staining. Conclusions Labeled BMSCs could migrate to the injured spinal cord segment after grafting via subarachnoid space,which could be tracked with MRI in vivo.