McConnell Brain Imaging Center, Montreal Neurological Institute and Hospital, Montreal, Quebec, Canada H3A 2B4.
Magn Reson Imaging. 2012 Jun;30(5):627-40. doi: 10.1016/j.mri.2012.02.006. Epub 2012 Apr 12.
The subthalamic nucleus (STN) is one of the most common stimulation targets for treating Parkinson's disease using deep brain stimulation (DBS). This procedure requires precise placement of the stimulating electrode. Common practice of DBS implantation utilizes microelectrode recording to locate the sites with the correct electrical response after an initial location estimate based on a universal human brain atlas that is linearly scaled to the patient's anatomy as seen on the preoperative images. However, this often results in prolonged surgical time and possible surgical complications since the small-sized STN is difficult to visualize on conventional magnetic resonance (MR) images and its intersubject variability is not sufficiently considered in the atlas customization. This paper proposes a multicontrast, multiecho MR imaging (MRI) method that directly delineates the STN and other basal ganglia structures through five co-registered image contrasts (T1-weighted navigation image, R2 map, susceptibility-weighted imaging (phase, magnitude and fusion image)) obtained within a clinically acceptable time. The image protocol was optimized through both simulation and in vivo experiments to obtain the best image quality. Taking advantage of the multiple echoes and high readout bandwidths, no interimage registration is required since all images are produced in one acquisition, and image distortion and chemical shift are reduced. This MRI protocol is expected to mitigate some of the shortcomings of the state-of-the-art DBS implantation methods.
底丘脑核（STN）是使用深部脑刺激（DBS）治疗帕金森病最常用的刺激靶点之一。该手术需要精确放置刺激电极。DBS 植入的常见做法是利用微电极记录来定位初始位置估计后具有正确电响应的部位，初始位置估计是基于线性缩放至患者术前图像上解剖结构的通用人脑图谱进行的。然而，这通常会导致手术时间延长和可能的手术并发症，因为在常规磁共振（MR）图像上难以可视化小尺寸的 STN，并且在图谱定制中没有充分考虑其个体间变异性。本文提出了一种多对比度、多回波磁共振成像（MRI）方法，该方法可通过在临床可接受的时间内获得的五个配准图像对比度（T1 加权导航图像、R2 图、磁化率加权成像（相位、幅度和融合图像））直接描绘 STN 和其他基底节结构。通过模拟和体内实验对图像协议进行了优化，以获得最佳的图像质量。利用多个回波和高读出带宽，由于所有图像都是在一次采集过程中生成的，因此不需要进行图像间配准，从而减少了图像失真和化学位移。该 MRI 协议有望减轻一些最先进的 DBS 植入方法的一些缺点。
