兔VX2肝种植肿瘤模型制作的完善及综合影像学评价

Consummation in making rabbit model bearing VX2 liver tumor and multiple imaging evaluation

目的进一步完善兔VX2肝种植肿瘤模型的制作,比较种植肿瘤的CT、MRI及DSA影像表现,评价各影像检查对瘤体显示的优越性。方法实验动物为新西兰大白兔(前期实验12只,后期实验24只),采用动物后肢皮下注射接种传代保存瘤种。模型前期制作采用包埋法接种．后期采用针头注入法接种于兔肝左叶,并于术前1 d及术后1、3 d、1、2周检查肝肾功能的动态变化情况。接种2周后行CT、MR成像,随后行经股动脉肝动脉超选择DSA及纳米磁性粒子介入治疗。结果前期实验肿瘤种植成功率66．7％,后期实验种植成功率100％。术后ALT、AST。有一过性增高,无统计学意义:BUN、Cr无明显变化。术后CT平扫肿瘤为略低密度病灶,强化不明显,境界清晰;MR平扫呈长T1、长T2信号;EPI序列T2WI呈略高信号影;DWI成像见高亮信号影,显示清晰;介入术中DSA造影可见肝左叶孤立的丰富血管肿瘤,供血动脉增粗,经超选择注入纳米磁性粒子,肿瘤内密度明显增高。结论兔VX2肝种植肿瘤模型是介入治疗实验研究理想的动物模型。VX2瘤粒针头注入法较包埋法成功率更高,其建立过程对兔肝肾功能无明显影响。CT平扫增强,MR平扫,EPI序列及DWI成像对于肿瘤的影像评价互有优势,EPI及DWI成像可更灵敏地显示肿瘤,DSA可清晰地显示肿瘤的供血及肝内有无转移。

Objective To consummate the creation of rabbit model bearing VX2 liver tumor ulteriorly, compare the imaging performance of CT, MRI and DSA in rabbit bearing VX2 liver tumor and evaluate the superiority of each imaging for demonstrating the tumors. Methods Thirty-six New Zealand white rabbits were enrolled including 12 designated in the fore stage experiment and 24 in the late stage experiment. The grafted VX2 carcinoma was maintained through serial transplantation into the hind limb of the rabbit by subcutaneous injection. In the fore stage experiment, the rabbits were embeded with VX2 tumor while in the late stage experiment, the rabbits were injected with VX2 tumor in the left lobe of the liver. Liver and kidney functions were checked I day before the operation and 1 d, 3 d, lw and 2 w after the operation in the late stage experiment. CT and MR imaging were performed in all of the rabbits 2 weeks later, together with the transeatheter arterial super-selection DSA and Manometer magnetic fluid interventional therapy. Results The successful rates of implantation were 66.7% in the fore stage experiment and 100% in the late stage experiment. Temporarily elevation of the serum ALT, AST levels was observed but reversed within a week with no statistical significance. Bun and Cr also showed no significant changes. The tumors demonstrated as low density on plain CT scan, inconspicuous enhancement on arterial phase image but well discernible from the surrounding liver tissue. On MR imaging the tumors appeared as low signal intenrts on T1WI, slightly high on T2WI （EPI） andmarkedly high on DWI. DSA revealed the isolated tumor with abundant tumor vessels supplied by enlarged feeding arteries in the left lobe of the liver and high density in the area of tumor after super-selective injection of the nanometer magnetic fluid. Conclusion The rabbit model with VX2 liver tumor is suitable for interventional experimental study. The injection method is superior to the embedded method with no obvious abnormal changes in the liver and kidney functions. CT （with-and without-contrast enhancement）and MRI （TI WI/T2WI,EPI/ DWI）were of benefits to the image evaluation of tumor with their own superiority, especially the T2WI（EPI）and DWI of MRI, DSA not only show the arterial details of the tumor but also metastasis in liver clearly.