兔VX2肝癌模型的制作及CT、MRI表现

Building of transplanted model of rabbits liver VX2 tumor and monitoring with CT and MRI

目的建立稳定的兔VX2移植性肝癌模型,分析少血供移植性肝恶性肿瘤的CT及MRI影像特征,与病理学相对照。方法取荷瘤兔后腿肌肉内VX2肿瘤,剪成小块后,经开腹种植于30只新西兰大白兔肝左叶或肝中叶,于种植后第2周、第3周分别进行CT及MRI增强扫描,统计肿瘤种植成功率,观察肿瘤体积及生长指数,分析肿瘤CT及MRI平扫和增强表现,区分富血供、少血供肿瘤;分别处死2只实验兔进行病理分析,与影像学相对照。结果VX2移植瘤种植成功22只;成瘤率为73%。2周与3周时肿瘤生长率有显著差异(P<0.01)。VX2移植瘤在CT及MRI上表现为占位性病变,呈类圆形或分叶状低密度或低信号结节,增强后发现少血供VX2移植瘤14只,表现为肿瘤无强化或轻微强化,肿瘤主体保持为低密度或低信号;富血供肝移植瘤8只,表现为肿瘤中度强化或明显强化,肿瘤主体密度或信号明显高于肝实质。光镜下肿瘤新生毛细血管虽较丰富,但纤细。结论经开腹种植法制作兔VX2肝移植瘤模型是一种简单、成功率高的建模方法,但易发生转移。CT及MRI平扫和增强扫描是检测肿瘤生长和血供的可靠方法,兔VX2肝移植瘤模型在CT与MRI上主要是一种少血供肝癌模型。

Objective To establish a stable transplanted model of hypovascular rabbit VX2 liver tumor, and analyze the CT and MRI manifestation of the implanted tumor, then a comparative observation was performed in microscope photographs and CT imaging. Methods Thirty white rabbits of New Zealand were included in the study. We extracted the VX2 tumor strain from subcutaneous tumor, then cut it into 1-2 mm^3 microblocks, a piece of tumor tissue were implanted into left or middle lobe of liver, CT and MRI were performed to distinguish the hypovascular liver tumor. And a comparative observation was performed in histopathology and imaging. Results The success rate of intrahepatic implantation of VX2 tumor was 73% （22/30）, the tumor were not detected in three rabbits, five rabbits have died in 3 days after implantation. There was significant difference of tumor growth ratio in the second week and the third week. The tumor were shown to be hypointense by unenhanced CT and MRI, non-enhancement or peripheral rim enhancement were observe in 14 cases, the main bodies of tumor remained hypointense. Conclusion The means of tumor particle implantation to make model of liver cancer is convenient and feasible. The CT and MRI are accurate and non-invasive method to monitor the growth and blood vessels of tumor, we found rabbit VX2 liver tumors are hypovascular tumors.