化学位移成像与T_2WI监控MR介导无水乙醇消融VX2兔的对照研究

Chemical-shift MR Imaging and T_2WI for Monitor of MR-guided Percutaneous Ethanol Injection for VX2 Tumors of Rabbits

目的在VX2兔经皮无水乙醇注射术(PEI)消融时,对化学位移成像和T2WI监控无水乙醇分布的效果进行评价。方法制备18只肝VX2瘤兔,在1.5T磁共振扫描仪下,应用FRFSE序列结合化学位移成像和FRFSE,T2WI序列完成试验模型和PEI术中监控的扫描。结果化学位移像上,注射部位的局部无水乙醇信号明显增加。在对VX2兔PEI时,化学位移成像使在肿瘤弥散的无水乙醇成像,T2WI在治疗后有多种信号改变。病灶信号在化学位移像与T2WI的信噪比和对比信噪比差异有显著性意义。无水乙醇分布范围与病理上肿瘤的坏死范围有正相关性。结论PEI时,化学位移成像能够比T2WI更精确地用于监控无水乙醇的分布。

Objective.. To assess the effect of chemical-shift magnetic resonance （MR） imaging and T2WI on mapping the distribution of ethanol during percutaneous ethanol injection （PEI） in rabbits bearing liver tumor. Methods：VX2 tumors were established in 18 rabbits. Chemical-shift MR imaging and T2 WI were performed for phantom and VX2 tumors of rabbits during PEI with FR FSE on a 1.5T MR scanner. Results： Focal increase of signal intensity was observed on cheminal shift MR imaging after PEI at the site of injection,and various signals were shown on T2 WI. There were significant differences in lesion-to-liver contrast-to-noise ratios on chemical-shift MR imaging and T2 WI. There was positive correlation between distribution of ethanal and extent of tumor necrosis on pathologic examination. Conclusion： Ethanol distribution may be more accurately monitored with chemical-shift MR imaging than with T2 WI during PEI.