MRI引导下射频消融治疗兔肝大血管旁VX2肿瘤的实验研究

发布时间：2018-05-06 07:34

本文选题：磁共振成像 + 血管　；参考：《福建医科大学》2015年硕士论文

【摘要】：目的:研究MRI引导下射频消融治疗较大血管旁(直径3mm)兔肝VX2肿瘤可行性及疗效,评价消融灶MRI表现及病理特征。方法:在2只新西兰雄性大白兔双侧后腿内侧肌肉组织接种VX2肿瘤,使之成瘤,作为建立兔肝大血管旁VX2肿瘤模型的细胞株。将11只新西兰雄性大白兔腿部肌肉注射氯胺酮1ml/kg和氯丙嗪0.5ml/kg,全麻后固定于MRI扫描床上,采用特定肝脏扫描序列,确定穿刺路径、方向及深度,在无菌条件下,用14G磁共振兼容穿刺针在MRI引导下逐步到达兔肝脏大血管(直径大于3mm)旁种植VX2肿瘤。2周后行MRI扫描,随机处死1只实验兔,行病理证实。剩余10只肿瘤兔在全麻及无菌条件下行1.5T MRI引导下病灶射频消融。维生素E丸定位,确定穿刺点及进针角度,用14G磁共振兼容穿刺针沿设定的进针角度穿刺,术中多次行T1WI-VIBE扫描以确定穿刺针进针方向,然后将RITA射频针沿着穿刺针针鞘进针,逐步进针穿透肿瘤。将扫描床退至原始位置,将射频针及皮肤电极导线与延长电缆连接,设定功率35W,靶温103 oC,消融时间12min。完成消融后行MRI扫描评估消融疗效,消融灶完全覆盖原病灶、范围超出病灶边缘0.5~1.0cm为消融完全,高信号环未完全包绕低信号瘤灶,则提示消融肿瘤残留,可予补充消融。MRI扫描后即刻将10只实验兔处死,行组织病理学检查,判断有无肿瘤残留。结果:1.11只实验兔肝脏VX2肿瘤均种植成功,共有12个瘤灶,11个瘤灶位于血管旁,未侵犯血管,1个瘤灶位于穿刺路径上,每个瘤灶直径为1.0~1.5cm(平均1.35cm)。瘤灶MRI表现:肿瘤灶在3D-VIBE上呈稍低信号,部分瘤灶中心液化坏死,呈更低信号;T2WI上呈稍高信号,部分瘤灶中央呈更高信号,邻近血管呈流空信号影。组织病理学检查证实为VX2肿瘤组织。2.对10只肿瘤兔均成功行RFA,11个瘤灶共消融20次,平均2次/个,其中4个瘤灶消融1次,5个瘤灶消融2次,2个瘤灶消融3次。瘤灶完全消融MRI表现:消融灶在T2WI上呈等低信号;3D-VIBE上呈同心圆状改变,中央区原病灶仍呈低信号,周边呈明显环状高信号,边界清晰,行病理检查,未发现肿瘤细胞。瘤灶不完全消融MRI表现:3D-VIBE上消融灶高信号环未完全包绕低信号瘤灶,组织病理检查证实为VX2肿瘤组织。结论:1.磁共振引导下兔肝大血管旁肿瘤种植是一种微创、有效的造模方法。2.MRI平扫可准确显示消融灶范围,是评价小肝癌射频消融疗效的有效手段。3.MRI引导下RFA治疗兔肝大血管旁VX2肿瘤是一种有效、可行的手术方法。
[Abstract]:Objective: to study the feasibility and efficacy of radiofrequency catheter ablation (RFCA) guided by MRI in the treatment of large paravascular (3 mm) rabbit liver VX2 tumors, and to evaluate the MRI findings and pathological features of ablation focus. Methods: two New Zealand male rabbits were inoculated with VX2 tumor in bilateral medial hind leg muscle tissue to establish VX2 tumor model. Ketamine 1ml/kg and chlorpromazine 0.5 ml / kg were injected intramuscularly into the legs of 11 New Zealand male white rabbits. After general anesthesia, the rabbits were fixed on the MRI scanning bed. The specific liver scanning sequence was used to determine the route, direction and depth of the puncture under aseptic conditions. Under the guidance of MRI, a 14G MRC-compatible puncture needle was used to gradually reach the hepatic large vessels (diameter > 3 mm) and implanted with VX2 tumor for 2 weeks, then MRI scan was performed. One experimental rabbit was killed at random and confirmed by pathology. The remaining 10 rabbits underwent 1.5 T MRI guided radiofrequency ablation under general anesthesia and aseptic conditions. Vitamin E pills were located, puncture point and angle were determined, 14G magnetic resonance compatible puncture needle was punctured along the set needle angle, T1WI-VIBE scan was performed many times during the operation to determine the direction of the needle, and then the RITA radio frequency needle was inserted along the sheath of the needle, and the needle was inserted along the sheath of the needle. Step by step the needle penetrates the tumor. The scanning bed was retreated to the original position, the radiofrequency needle and the skin electrode wire were connected with the extended cable, the power was set at 35 W, the target temperature was 103 OC, and the ablation time was 12 min. After ablation, MRI scan was performed to evaluate the effect of ablation. The ablation focus completely covered the original lesion, the range beyond the margin of the lesion was complete 0.5~1.0cm, and the hyperintense loop was not completely wrapped around the hyposignal tumor, which indicated that the ablation was residual. Ten experimental rabbits could be killed immediately after ablation. MRI scanning. Histopathological examination was performed to determine whether there were tumor residues. Results VX2 tumors were successfully implanted in the liver of 1. 11 rabbits. There were 12 tumor foci, 11 lesions were located beside the blood vessels, and 1 tumor focus was located on the puncture path. The diameter of each tumor was 1. 0 ~ 1. 5 cm (mean, 1. 35 cm). The MRI findings of tumor focus were as follows: low signal intensity on 3D-VIBE, liquefaction and necrosis in the center of some tumor foci, slightly high signal intensity on T _ 2WI with lower signal intensity, higher signal intensity in the center of some lesions, and flow empty signal in adjacent vessels. Histopathological examination confirmed VX2 tumor tissue. 2. RFA was successfully performed in 10 tumor rabbits. The 11 lesions were ablated 20 times (mean 2 times per tumor), of which 4 lesions were ablated once, 5 tumors were ablated twice, and 2 lesions were ablated 3 times. MRI findings of complete ablation: the lesion showed concentric circular changes on T2WI with isohypointential signal intensity 3D-VIBE, low signal intensity in the central area, obvious annular hyperintensity around the lesion, clear boundary, pathological examination, and no tumor cells were found. MRI findings of incomplete ablation of tumor foci showed that the hyperintense loop of the ablation focus on 3 D-VIBE was not completely wrapped around the low signal signal tumor. Histopathological examination confirmed that the tumor tissue was VX2. Conclusion 1. MR-guided implantation of paravascular tumor in rabbit liver is a minimally invasive method. 2. Plain MRI scan can accurately show the extent of ablation focus. It is an effective method to evaluate the curative effect of radiofrequency ablation of small hepatocellular carcinoma. 3. MRI-guided RFA is an effective and feasible surgical method for the treatment of rabbit paravascular VX2 tumor.
【学位授予单位】：福建医科大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R735.7;R445.2

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