快速成像序列在常规MRI导向下肝脏病变介入治疗中的初步应用

目的研究MRI兼容性穿刺针在快速成像序列中的显示以及常规MRI导向下肝脏介入的初步临床应用。方法将MRI兼容性穿刺针（19.5G,COOK）插入离体新鲜猪肝中,在0.5T中场超导常规MRI中成像,穿刺针与主磁场方向（B0）分别成角0°、30°、60°、90°,采用FSET2WI、FSET1WI、FE序列行冠状位、矢状位及轴位扫描,测量图像上穿刺针直径。5例患者在常规1.5TMRI引导下行经皮穿刺介入治疗,2例为肝囊肿抽吸硬化治疗,另3例共11个肝癌病灶行125I放射性粒子植入治疗。结果在各扫描序列中,穿刺针均显示为信号缺失。在与B0成角0°、30°、60°、90°时显示的穿刺针直径分别为（2.38±0.42）mm、（3.72±1.24）mm、（6.27±1.92）mm、（11.3±1.78）mm（P〈0.05）;采用FSET2WI及FSET1WI序列获取的穿刺针直径分别为（4.52±3.87）mm及（4.74±3.68）mm（P〉0.05）;FE序列扫描显示的穿刺针直径为（8.26±4.37）mm,与FSE序列显示的穿刺针直径之间的差异有统计学意义（P〈0.05）。5例MRI导向下治疗均顺利完成,穿刺针显示清晰。结论常规MRIFSE、梯度回波等快速成像序列具备一定的组织分辨力和时间分辨力,能有效引导肝脏介入操作。

Application of fast imaging sequences in conventional MRI-guided intervention of liver diseases

Objective To investigate the display of MRI-compatible puncture needle in fast imaging sequences and the preliminary application of conventional MRI-guided intervention of liver diseases. Methods A MRI compatible puncture needle (19.5G, COOK) was inserted into an in vitro pork liver in a 0.5T conventional MRI, with the angles between needle and B0 were 0°, 30°, 60° and 90°, respectively. The multi-sequences scans of FSE T2WI, FSE T1WI and FE were performed, the scanning directions were axial, sagittal and coronary with the long axis. Then the diameters of needle were measured. Five patients underwent percutaneous interventional treatment under the guidance of conventional MRI, including 2 patients of hepatic cyst treated with MRI-guided aspiration and indurascent and 3 patients with 11 hepatic carcinoma lesions treated with MRI-guided ¹²⁵I seed implantation. Results All puncture needles demonstrated signal absence. The needle diameters of 0°, 30°, 60°and 90° with B0 were (2.38±0.42) mm, (3.72±1.24) mm, (6.27±1.92) mm and (11.3±1.78) mm, respectively (P<0.05). The diameters of needle on the images of FSE T2WI and FSE T1WI were (4.52±3.87) mm and (4.74±3.68) mm, respectively (P>0.05).The diameter of needle on the images of FE was (8.26±4.37) mm, the difference between FSE and FE was statistically significant (P<0.05). Five cases of MRI-guided intervention were completed smoothly, and the needle displayed clearly. Conclusion The fast imaging sequences of conventional MRI (such as FSE and GRE) possesses some extent of tissue and temporal resolution, and can be used effectively in MRI-guided intervention of liver deseases.