磁共振氢质子波谱评价无水乙醇消融治疗兔软组织VX2肿瘤疗效

~1H-MRS in the evaluation of response of rabbit soft tissue VX2 tumor to percutaneous ethanol injection therapy

目的：利用磁共振氢质子波谱（^1 H-MRS）来评价无水乙醇消融治疗兔软组织VX2肿瘤的疗效。方法：15只新西兰大白兔，雌雄不限，体重2．5-3．0 kg，在其右侧大腿内侧注射VX2肿瘤组织悬浮液各约0．2 mL，制备成荷瘤兔，于肿瘤组织接种后第14天行常规磁共振扫描，及氢质子波谱成像扫描，采用单体素（SVS）点分辨表面定位序列（PRESS）扫描，TR 1500 ms，TE 144 ms，激励次数8。扫描后第2天在磁共振导引及监视下行无水乙醇注射消融治疗。消融治疗后分别于第7、10天再行常规磁共振扫描及 MRS扫描，扫描参数与术前一致。观察磁共振常规扫描术前与术后肿瘤信号特点的变化；术前与术后 MRS波谱扫描谱线的质量、特点分析；比较术前与术后Cho/Lipid峰高值和峰下面积的比值，将扫描所得的数据利用机器自带的functool功能软件在磁共振扫描仪上进行分析，利用SPSS 17．0软件包进行统计分析。结果：术前肿瘤组织呈等信号或稍低信号（T1 WI）和明显的高信号（T2 WI），术前肿瘤组织Cho 峰为第一高峰，Lipid 峰为第二高峰，Cr峰为最小峰；而术后消融坏死的肿瘤组织Lipid峰变为第一高峰，Cho 峰较术前明显下降而成为第二高峰，Cr 峰还是最小峰；术前Cho/Lipid峰高值的比值为1．2539±0．3537，峰下面积的比值为1．1357±0．2684；术后7天和10天Cho/Lipid峰高值的比值分别为0．3027±0．1132，0．3125±0．1087；峰下面积的比值分别为0．2589±0．1086，0．2673±0．1145。术后Cho/Lipid峰高值和峰下面积的比值较术前均明显降低，两者比较差异有统计学意义（P＜0．05）。结论：磁共振氢质子波谱用来评价无水乙醇消融治疗兔软组织VX2肿瘤的疗效有意义，治疗早期肿瘤实质的Cho峰较术前明显下降，Cho/Lipid峰高值和峰下面积的比值较术前明显降低。

Objective：To evaluate the therapeutic effect value of percutaneous ethanol injection in VX2 soft tissue tumor in the posterior limb of rabbit by using ^1 H-MRS.Methods：Fifteen healthy New Zealand white rabbits were included in this study.Animal model was created by injecting 0.2mL tumor tissue suspensions into the proximate of rabbit posterior limb.After 2 weeks,all the rabbits underwent conventional MRI and ^1 H-MRS （TR 1500ms,TE 144ms,NEX 8）examination.Percutaneous ethanol injection （PEI）were performed to all the tumors under the guidance of MR in the next day of the examination.Conventional MRI and ^1 H-MRS examinations were performed to all the rabbits on 7,10 days after PEI.The signal characteristics of tumors pre-operation and post-operation were analysed.The characteristics of the tumors＆#39;MRS spectrum preoperative and postoperative,i.e.the Cho/Lipid peak value,was calucated before operation and after operation. Statistical analysis was used with SPSS 17 .Results：MRI scanning showed a low signal of the tumor on T1 WI and a high sig-nal of the tumor on T2 WI before PEI.Before operation,Cho peak （3.2ppm）of the tumor was the first peak,Lipid peak （1.4ppm）was the second peak and Cr peak （3.02ppm）was minimum;However,after PEI,the Lipid peak changed into the first peak,Cho peak went down and became the second peak.Cho/Lipid values of pre-PEI （1.2539 ±0.3537,1.1357 ± 0.2684）were higher than those of post-PEI （0.3027±0.1132,0.2589±0.1086;0.3125±0.1087,0.2673±0.1145）.The difference was statistically significant （P＆lt;0.05）.Conclusion：It is possible to apply ^1 H-MRS to evaluate the therapeutic effect of PEI in VX2 soft tissue tumor in the posterior limb of rabbit.The peak high values and the ratio of the area under the peak of Cho/Lipid were decreased obviously at the early phase after PEI therapy.