丘脑底核磁共振成像技术研究进展

Recent progresses of magnetic resonance imaging of subthalamic nucleus

丘脑底核(subthalamic nucleus,STN)是我国帕金森病患者接受脑深部电刺激(deep brain stimulation,DBS)治疗的主要核团。磁共振(MRI)影像个体化、精确植入电极至STN的感觉运动部要求MRI成像对STN边界清晰划分,并确保图像保真。目前使用的MRI序列可分为3大类:基于自旋回波序列的T_2加权成像、反转恢复序列、扩散张量成像、各向异性分数;基于磁化转移技术的磁敏感加权成像、自由衰减的T_2*成像等;基于磁敏感图像重建技术的定量磁敏感图谱。其中,定量磁敏感图谱的STN与周边的信噪比最优、边界最清晰,T_2*技术次之;T_2加权成像在患者戴框架时几何精度较高,适合戴框架直接定位使用。

Subthalamic nucleus（STN）is the main target nucleus for deep brain stimulation（DBS）treatment in patients with Parkinson disease.To implant the electrode on the sensorimotor part of STN individually and accurately,the boundary of STN is required to be clarified clearly on the magnetic resonance imaging（MRI）without geometric distortion.At present,there are three categories of MRI sequences：spin echo sequence including T_2-weighted imaging（T_2WI）,inversion recovery（IR）,diffusion tensor imaging（DTI）,and fractional anisotropy（FA）;magnetization transfer technique including magnetic susceptibility weighted imaging（SWI）and T_2-weighted magnitude imaging（T_2＊WI）;image reconstruction technique such as quantitative susceptibility mapping（QSM）.It is found that QSM can provide optimal signal-noise ratio to identify the boundary of STN,T_2＊ technique comes second.T_2WI has high geometric accuracy when the patients wear frame,which is appropriate for direct DBS implantation on STN with frame.