兔VX2肝移植瘤及正常肝组织的磁共振灌注成像的对比研究

目的通过对比分析兔VX2肝移植瘤及正常肝组织磁共振灌注成像（PWI）特点及灌注参数之间的差别,探讨PWI相关参数在肿瘤血流灌注评估中的价值。方法对24只新西兰大白兔采用手术直视下瘤组织块包埋法建立兔VX2肝移植瘤模型,在实验兔接种后第21天行MRI检查,获得肝肿瘤组织和正常肝组织的信号强度-时间曲线,并分别记录各感兴趣区的平均强化时间（MTE）、负增强积分（NEI）、达峰时间（TM）、最大下降斜率（MSD）和最大上升斜率（MSI）,并将肿瘤组织与正常肝组织的各灌注参数进行比较。结果兔VX2肝移植瘤模型中的正常肝组织的MTE、NEI、TM、MSD和MSI分别为（208.341±2.226）ms、78.334±8.152、（24.059±1.927）ms、38.221±2.443和15.389±2.526,肿瘤组织相应的各参数分别为（175.437±4.182）ms、123.203±19.455、（17.061±1.834）ms、125.740±4.842和67.832±2.882。肿瘤组织的MTE和TM低于正常肝组织,而NEI、MSD和MSI则高于正常肝组织（P〈0.05）。结论肝脏PWI各灌注参数能较好地区分肿瘤组织与正常肝组织,有助于评估肝脏肿瘤组织灌注特点。

Comparative study of rabbit VX2 hepatic implantation tumor and normal liver tissue on magnetic resonance perfusion weighted imaging

Objective To investigate the value of magnetic resonance（MR） perfusion weighted imaging（PWI） in evaluating the blood perfusion of tumor by analyzing the features and indexes of PWI on rabbit VX2 hepatic implantation tumor and normal liver tissue.Methods Twenty-four New Zealand White rabbits with VX2 carcinoma were established under direct surgical vision embedding tumor tissue.MR examination was performed at 21 days after the tumor implantation.The signal intensity-time curve of hepatic tumor and normal liver tissue were obtained.Mean time to enhance（MTE）,negative enhancement integral（NEI）,time to minimum（TM）,maximum slope of decrease（MSD） and maximum slope of increase（MSI） were measured.Results MTE,NEI,TM,MSD,and MSI of the normal liver tissue were 208.341±2.226 ms,78.334±8.152,24.059±1.927 ms,38.221±2.443,and 15.389±2.526,respectively.MTE,NEI,TM,MSD,and MSI of the tumor tissue were 175.437±4.182 ms,123.203±19.455,17.061±1.834 ms,125.740±4.842,and 67.832±2.882,respectively.The MTE and TM of tumor were shorter than those of normal hepatic tissue（P〈0.05）.NEI,MSD,and MSI of tumor were higher than those of normal hepatic tissue（P〈0.05）.Conclusion PWI can distinguish the normal liver tissue from the tumor tissue,which is helpful in evaluating blood perfusion of different hepatic tissues.