SPIO与Gd-DTPA联合增强检测大鼠肝癌病灶的实验研究

目的 :观察联合使用SPIO和Gd DTPA对大鼠肝癌模型的增强特点。材料和方法 :制作 3 0只大鼠肝癌模型 ,增强前后行MR扫描 ,平扫序列包括SE、TSE、GRE的T1、T2WI序列。增强扫描分为 4组 ,其中Gd +SPIO联合增强组 10只 ,先注射Gd DTPA ,行SE、GRET1WI扫描 ,随后给予SPIO造影剂 ,扫描序列同平扫 ;SPIO +Gd联合增强组 10只 ,先注射SPIO ,行SE、GRET1WI扫描 ,12min后再给予Gd DTPA ,扫描序列同平扫 ;Gd、SPIO增强组各为 5只 ,增强扫描序列同平扫。分析各增强扫描组中病灶的增强特点。结果 :两种联合增强方法中 ,肝脏信号强度在所有扫描序列中均较平扫时下降 ,但与SPIO增强组无差异 ;病灶的SNR、CNR在SE、GRET1WI中明显高于平扫和SPIO、Gd DTPA增强法 ;在T2WI中病灶的SNR、CNR和单独使用SPIO无显著性差异。两种联合增强方法之间的SNR和CNR在每种扫描序列中没有显著性差异。结论 :SPIO和Gd DTPA联合增强方法利用了两种造影剂的优势 ,增加了肿瘤病变的对比 ,可提高发现病变的几率。

SPIO and Gd-DTPA Combining Enhancements for Detection of Hepatocellular Carcinoma Nodules in Rats Model

Purpose:To assess the MR characteristics of rat liver carcinoma after SPIO combining with Gd-DTPA enhancement.Materials and Methods:Experimental model of hepatocellular carcinoma was induced in 30 SD rats. All the animals were imaged with T1-and T2-weightd pulse sequences before administration of contrast agents. The dual-contrast methods of simutaneous administrations of Gd-DTPA and SPIO was achieved by the following two ways: Gd+SPIO method was achieved by first administrating Gd-DTPA to 10 rats, and performed SE?GRE T1WI, then administrate SPIO and performed MR imaging, pulse sequences were identical to those used in unenhancement. SPIO+Gd method was achieved by first administrate SPIO to 10 rats, and performed SE?GRE T1WI, Gd-TP was administrated 12 minutes later, MR pulse sequences were performed as those used in unenhancement. Gd-DTPA and SPIO were administrated to 5 rats respectively, the same sequences were performed as those used in unenhancement. The MR characters of different enhancement methods were analyzed by calculating SNR and CNR of tumors and normal liver.Results: When both contrast agents were administrated together, the CNR was greater than that of unenhanced?SPIO-enhanced, and Gd-DTPA-enhanced methods in SE and GRE T1WI, SI of liver was deceased significantly in all sequences. The SNR and CNR in T2-weighted imaging had no difference with SPIO-enhanced method. And there is no significant difference in the CNR and SNR of Tumors between two kinds of dual contrast methods in all sequences.Conclusion: Dual contrast imaging shows a synergistic effect of SPIO and Gd-DTPA, maximizing the CNR and increasing the conspicuity of focal liver lesions.