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

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.

Chemical-shift MR Imaging and T2 WI for Monitor of MR-guided Percutaneous Ethanol Injection for VX2 Tumors of Rabbits

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 T2WI 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 T2WI.There were significant differences in lesion-to-liver contrast-to-noise ratios on chemical-shift MR imaging and T2WI.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 T_2WI during PEI.