0.23 T开放性磁共振实时引导下经皮激光热消融术 治疗肝脏恶性肿瘤

目的 评价肝脏肿瘤在磁共振介入激光治疗中的热消融变化及光学器械追踪系统对激光纤维的精确定位和实时监测激光治疗中热消融变化的能力，观察激光消融治疗肝脏恶性肿瘤的可行性与安全性。方法 对经病理学活检证实的14例恶性肝脏肿瘤患者(4例为肝细胞癌，10例为肝转移瘤，共22个肿瘤)进行0．23T开放性磁共振成像系统与介入引导下经皮激光热消融治疗术。结果 全部病灶均被成功定位、靶定并消融治疗。肿瘤形态、术后瞬间及3天后热消融形成的凝固坏死灶均在磁共振图像上显示。除1例有部分残余外，所有热消融灶均大于各自原始肿瘤大小；术后3天热消融凝固灶大于术后瞬间凝固灶。结论 磁共振引导经皮肝脏肿瘤激光热消融术是可行和安全的；光学追踪系统引导与磁共振温度监测对准确估计热治疗效果是有用且可信赖的工具。

The real-time MRI (0.23 T open scanner) guidance and monitoring in percutaneous laser ablation of liver tumors

Objective To evaluate the ability of real-time opt ical instrument tracking system integrated to the MRI scanner as a guidance and monitoring facility in positioning instrument and monitoring ablation of liver t umors, and to describe the feasibility and safety of laser ablating malignant l iver tumors. Methods Total 22 hepatic tumors in 14 patients (11 males, 3 females, mean age 63.5 years), of which 10 were metastases and 4 were primary hepatocellular carcinoma (HCC), were treated with total thermal ablati on. 0.23 T open MR scanner and Nd-Yag type laser device was used. Completely ba lanced steady state (CBASS) sequence was used for lesion location, and field ech o (FE) T1 sequence for thermal monitoring. A 18 G needle was used for initial ap proach. Results All the lesions scheduled were successfully loc alized, targeted, and treated under the MRI guidance. All the treated patients w ere discharged 3 days after interventional therapy. With both T1- and T2-weigh ted sequences, the ablated liver tissues were exactly depictable and provided pr ecise delineation of the ablated tissue volume. On post-procedure and follow-u p contrast-enhanced MR images, the thermal ablated lesions appeared avascular a nd necrotic. MRI showed the size of initial tumor, and the size of the coagulati ve necrosis after procedure immediately and 3 days later, in which all except on e were slightly larger than initial tumors respectively. There was statistically significant differences in mean maximum of necrosis diameter between intraproce dure and that of 3 days later on T1- and T2-weighted images. Conclusio n MRI-guided percutaneous laser thermal ablation of liver tumors is fe asible and safe. The optical tracking system and intraprocedural thermal monitor ing with MRI prove to be useful and reliable tools for estimating the effects of thermotherapy accurately.[