CT引导下经皮肝穿刺接种兔肝VX2肿瘤模型的建立及其肿瘤的CT、MRI评估

Establishing the rabbit liver VX2 tumor model using CT-guided percutaneously transhepatic puncture inoculation and evaluating the model using MRI and CT

目的在计算机体层成像(CT)引导下,应用3D打印模板建立经皮穿刺接种兔肝VX2肿瘤模型,评价CT与核磁共振(MRI)对肿瘤的检测价值。方法通过CT引导3D打印模板经皮穿刺肝脏,将VX2肿瘤组织碎片植入16只新西兰白兔的肝脏中,建模后12~14 d进行CT、MRI平扫和增强检查,获取DCE-MRI参数;后处死兔子取肝脏行HE染色及免疫组织化学染色,计算微血管密度(MVD),动态对比增强磁共振成像(DCE-MRI)参数[体积转移常数K(K trans)、回流速率常数(K ep)、容积分数(Ve)、初始1 min钆浓度时间曲线下面积(iAUC60)]与MVD的相关性。结果建模后12~14 d行CT、MRI扫描检查,16只兔均接种成功;VX2肝肿瘤的CT平扫表现为低或等密度结节或肿块影,边缘模糊,增强扫描显示动脉期肿瘤明显强化,呈环形高密度影,门脉期肿瘤密度降低至等密度,边缘及正常的肝实质增强;MRI显示VX2肝肿瘤T1W图像低信号、T2W图像和DW图像高信号,采用增强MRI灌注成像技术通过DCE-MRI的参数(K trans和iAUC60)可以提供有关血管血液灌注和血管通透性的功能性信息;16只兔子肝VX2肿瘤中平均MVD为(23.858±2.115)个/视野,K trans和iAUC60与MVD呈正相关(r=0.545、0.553,P=0.029、0.026)。结论CT引导经皮肝穿接种兔VX2模型成功率高,该模型的肿瘤大小、密度及血管生成情况可通过CT和MRI检测、评价。

Objective To evaluate detection value of computed tomography(CT)and magnetic resonance imaging(MRI)in a rabbit liver VX2 tumor model established by CT-guided percutaneously transhepatic puncture inoculation with the help of a 3D printing template for positioning a rabbit.Methods Sixteen New Zealand white rabbits were fixed in 3D printing template and inoculated with VX2 tumor tissue fragments in livers by CT-guided percutaneously transhepatic puncture.On day 12 to day 16 after inoculation,CT and MRI plain scan and enhanced examination were performed to obtain dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)parameters.The rabbits were sacrificed and the liver tissues were stained with HE and immunohistochemistry(IHC).Microvessel density(MVD)was calculated,the association of DCE-MRI parameters(volume transfer constant K(K trans),reflux rate constant(K ep),volume fraction(Ve),area under the initial 1-min gadolinium concentration-time curve(iAUC60)]with MVD was analyzed.Results CT and MRI scans showed that 16 rabbits were successfully inoculated.CT plain scan of VX2 liver tumor showed low or iso-density nodules or mass shadows with blurred edges.Enhanced scan showed that obviously enhanced tumors and circular high density in arterial phase,but tumors with iso-density density,enhanced margin and normal hepatic parenchyma in portal phase.MRI showed that VX2 liver tumors had low signal on T1W images,high signal on T2W images and DW images.Enhanced MRI perfusion imaging provided functional information about vascular blood perfusion and vascular permeability through DCE-MRI parameters(K trans and iAUC60).In 16 rabbits with liver VX2 tumors,the average MVD was(23.858±2.115)/per visual field,and K trans and iAUC60 were positively correlated with MVD(r=0.545,0.553;P=0.029,0.026).Conclusion CT-guided percutaneously transhepatic puncture inoculation of rabbit VX2 model has a high success rate.The tumor size,density,and angiogenesis of this model can be detected,and evaluated by CT and MRI.