SPIO增强MRI对兔肝脏微小肿瘤检出的研究

SPIO-enhanced MRI evaluation of rabbit bearing VX2 micro-hepatoma

目的探讨超顺磁性氧化铁(SPIO)增强MR不同序列成像对兔VX2肝微小肿瘤病灶的检出率.方法 15只新西兰大白兔肝内种植VX2肿瘤,分别在种植肿瘤后7天、14天行MR SE T1WI、FSE T2WI、GRE T2*WI、GRE T1WI平扫和SPIO增强扫描,记录不同检查序列所显示的肿瘤数目,比较显示率,确定SPIO增强MRI最佳扫描参数.结果 15只兔肝内种植VX2肿瘤后共有15个肿瘤生长,成功率100%.种植后7天肿瘤<5 mm,SPIO增强序列GRE T2*WI、GRE T1WI可显示所有的肿瘤病灶,显示率为100%,明显优于MRI平扫,SPIO增强SE T1WI及FSE T2WI序列,GRE T2*WI序列有更好的肿瘤-肝实质信号对比.14天后,肿瘤生长到1～2 cm, 除GRE T2*WI序列平扫显示率增加外,其他各检查方法对病灶的显示没有明显的差异.结论 SPIO增强MRI的GRE T2*WI、GRE T1WI序列对兔肝脏VX2微小肿瘤具有同样的高检出率,进行SPIO肝脏增强MRI检查时,GRE T2*WI序列是首选序列.

Objective To investigate the value of superparamagnetie iron oxide （SPIO） enhanced MRI with different sequences in detection of rabbit bearing VX2 micro-hepatoma. Methods Plain and SPIO-enhanced MRI were performed for all rabbits bearing VX2 tumor in the liver with the sequences of SE T1WI, FSE TSWI, GRE T2 WI and GRE T1WI. Microhepatoma was determined at different sequences and the tumor detectability was statistically analyzed respectively. Results Fifteen tumors grew from 3 mm to 5 mm in diameter with success rate of 100% at 7 days after the implantation. Total 15 tumors were depicted by GRE T2· WI and GRE T1WI. There was markedly statistical difference （P〈0.01） compared with other sequences. Fourteen days later, tumors grew to 1-2 cm in diameter. Apart from GRE T2 ·WI without SPIO enhancement, the rest of imaging modality had the same detectability of tumors （P〉0.05）. Conclusion SPIO-enhaneed MRI can significantly increase the detectability of VX2 micro-tumors in rabbit livers and GRE T2 · WI is the best sequence in depicting hepatic micro-tumors.