肝脏快速容积采集序列增强扫描评估兔VX2肝癌模型血供

Evaluation on blood supply of hepatic VX2 tumor in rabbit model using liver acquisition with volume acceleration sequence enhancement scanning

目的探讨肝脏快速容积采集(LAVA)序列增强扫描评估兔VX2肝癌模型血供的价值。方法以40只新西兰大白兔建立兔VX2肝癌模型。于建模后2～3周对实验兔行腹部MR平扫及LAVA序列增强扫描,比较平扫T1 WI、T2 WI及LAVA序列增强扫描的病灶检出率,分析肿瘤MRI表现及强化特点;根据LAVA序列增强扫描肿瘤的强化特点,分为均匀明显强化、不均匀强化及环状强化三种强化方式(均匀明显强化组、不均匀强化组及环状强化组),每组各处死2只实验兔进行病理检查。结果 32只建模成功,共32个病灶。LAVA序列增强扫描的病灶检出率(32/32,100%)高于平扫T1 WI(20/32,62.50%)及T2 WI(23/32,71.88%)的检出率(χ2=12.410、8.275,P均<0.05);平扫T1 WI与T2 WI的病灶检出率差异无统计学意义(χ2=0.638,P>0.05)。MR平扫肿瘤呈类圆形或不规则形,T1 WI低、T2 WI高或混杂信号。LAVA序列增强扫描中,2个病灶表现为均匀明显强化,11个病灶不均匀强化,19个病灶环状强化。病理检查示均匀明显强化组及不均匀强化组肿瘤内毛细血管较多,而环状强化组肿瘤内毛细血管较少。结论 LAVA序列增强扫描对兔肝XV2肿瘤检出率高,且对肿瘤血管显示效果佳,可较为客观、全面地反映VX2肿瘤的生长特性。

Objective To explore the value of MR enhanced scanning using liver acquisition with volume acceleration（LAVA） sequence in evaluating blood supply of VX2 tumor in rabbit models.Methods Hepatic VX2 tumor models were established in 40 New Zealand white rabbits.Conventional MR and the enhanced scanning with LAVA sequence were performed in all the rabbits 2—3 weeks after tumor implantation.The detection rates of the lesions with T1WI,T2WI and the enhanced scanning with LAVA sequence were compared.Moreover,the MRI findings and the features of enhancement of tumors were analyzed.According to the enhance features,there were 3 kinds of enhancement： Significant equality enhancement,heterogeneous enhancement and ring-enhancement.Two rabbits of each kind of enhancement were randomly chosen for pathological examination.Results Totally 32 rabbits were successfully implanted with VX2 tumor（32 lesions）.The detection rate of the enhanced scanning with LAVA sequence（32/32,100%） was significantly higher than those of T1WI（20/32,62.50%,χ2=12.410,P0.05） and T2WI（23/32,71.88%,χ2=8.275,P0.05）,while there was no significant difference of detection rate between T1WI and T2WI（χ2=0.638,P0.05）.VX2 tumor revealed as round or irregular mass with low signal on T1WI,high or mixed signal on T2WI.Among all the 32 lesions,significant equality enhancement,heterogeneous enhancement and ring-enhancement was found in 2,11 and 19,respectively.Pathological examination showed that capillaries were scarce in ring-enhancement tumors,while there were numerous capillaries in tumors of significant equality enhancement and heterogeneous enhancement.Conclusion LAVA sequence enhancement scanning is a valuable method in detecting hepatic VX2 rumor with high detection rate,therefore can reflect the growth characteristics of the tumor objectively and completely.