摘要
目的探讨磁共振(magnetic resonance imaging,MRI)对超顺磁性氧化铁(superparamagnetic ironoxide,SPIO)标记的胰岛细胞在大鼠肝脏内的成像方法,用于监测胰岛细胞移植术后移植物在大鼠体内的存活及排异情况。方法采用GE 3.0T Signa Excite磁共振扫描仪,配合3英寸小动物线圈。实验动物为20只雄性Wistar大鼠和5只雄性Lewis大鼠。将SPIO标记的胰岛细胞移植入大鼠肝脏内,未用SPIO标记的作为阴性对照,比较两组的差异。对SPIO标记后移植的大鼠分别用FSE T2WI序列和GRE T2*WI序列扫描,比较序列敏感性的差异。分别将取自Wistar大鼠和Lewis大鼠的胰岛细胞,用SPIO标记后移植入Wistar大鼠肝脏内,观察两移植组受体体内的胰岛细胞存活及排异的情况。将同基因移植组的大鼠于移植术后3月处死,异基因移植组的大鼠于移植术后3周处死,作病理切片,将所得结果与MRI的图像进行对照。结果只有SPIO标记后的胰岛细胞可以被MRI监测到,表现为肝实质背景上的低信号点。GRE T2*WI较FSE T2WI序列对SPIO的监测更敏感。同基因移植组于移植后第1周、第2周及第3周的低信号点相对数量分别为(90.03±9.52)%、(92.87±18.21)%和(86.25±24.81)%,而异基因组的相对数量分别为(41.40±15.41)%、(33.41±14.01)%和(23.58±16.78)%。两组相对数量之间的差异具有显著的统计学意义(P<0.01)。病理结果显示,标记后的胰岛细胞内确实存在铁颗粒,同基因移植组3月后在肝窦内仍能找到保存完好的移植物,而异基因组在移植后3周只有极少量的移植物残留。结论MRI能对大鼠体内SPIO标记的胰岛细胞进行成像,用于活体实时监测胰岛细胞移植术后移植物的存活及排异情况。
Objective To track superparamagnetic iron oxide （SPIO）-labeled pancreatic islet cells in rats using 3. 0T magnetic resonance imaging （MRI）, and to detect the survival and rejection of grafts after transplantation. Methods Twenty male Wistar rats and 5 male Lewis rats were included in the study. SPIO labeled pancreatic islet cells were tracked using a GE 3.0T Signa Excite MRI scanner with an animal coil. The images of SPIO-labeled islet cells in rats after transplantation were compared with those of the unlabeled ones. FSE T2WI sequence and GRE T2 ＊ WI sequence were used for the detection. The sensitivity of images for detection of grafts was also compared. SPIO-labeled pancreatic islet cells isolated from Wistar and Lewis rats were transplanted into the liver of Wistar rats. Afterwards, the survival and rejection of islet cells were observed sequentially in these two growps. The rats in the syngeneic group were sacrificed 3 months post-transplantation, while the rats in the allogeneic group were sacrificed 3 weeks post-transplantation. MRI of the grafts were correlated with the pathological results. Results SPIO-labeled pancreatic islet cells were seen on MRI as distinct homogenous, hypointense spots in the liver. GRE T2 ＊ WI SPIO-labeled islet cells than FSE T2WI. The relative count of were more sensitive to the detection of hypointense spots in the syngeneic group were （90.03±9.52）%, （92.87±18.21）% and （86.25±24.81）%, respectively at 1 week, 2 weeks and 3 weeks after transplantation, while the relative count in the allogeneic group were （41.4（1 ±15.41）%, （33.41±14.01）% and （23. 58 ±16. 78）%, respectively. The difference between these counts was statistically significant （P〈0.01）. Iron particles were detected only in the SPIO-labeled cells. Three months post-transplantation, the grafts were found well-preserved in the liver of the rats of the syngeneic group, while only a few grafts were found in that of the aUogeneic group. Conclusions MRI can be used to track S
出处
《复旦学报（医学版）》
CAS
CSCD
北大核心
2009年第6期670-674,共5页
Fudan University Journal of Medical Sciences
基金
国家自然科学基金项目(30671986)
关键词
胰岛细胞移植
磁共振
超顺磁性氧化铁
活体监测
pancreatic islet cell transplantation
magnetic resonance imaging
superparamagnetic iron oxide
track in vivo
