Fayed Islam, Syed Mashaal, Gingold Eric, Alizadeh Mahdi, Sharan Ashwini, Wu Chengyuan
Department of Neurosurgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia , Pennsylvania , USA.
Department of Radiology, Thomas Jefferson University, Philadelphia , Pennsylvania , USA.
Neurosurgery. 2023 Nov 1;93(5):1036-1045. doi: 10.1227/neu.0000000000002536. Epub 2023 May 25.
Directional leads have garnered widespread use in deep brain stimulation (DBS) because of the ability to steer current and maximize the therapeutic window. Accurate identification of lead orientation is critical to effective programming. Although directional markers are visible on 2-dimensional imaging, precise orientation may be difficult to interpret. Recent studies have suggested methods of determining lead orientation, but these involve advanced intraoperative imaging and/or complex computational algorithms. Our objective is to develop a precise and reliable method of determining orientation of directional leads using conventional imaging techniques and readily available software.
We examined postoperative thin-cut computed tomography (CT) scans and x-rays of patients who underwent DBS with directional leads from 3 vendors. Using commercially available stereotactic software, we localized the leads and planned new trajectories precisely overlaying the leads visualized on CT. We used trajectory view to locate the directional marker in a plane orthogonal to the lead and inspected the streak artifact. We then validated this method with a phantom CT model by acquiring thin-cut CT images orthogonal to 3 different leads in various orientations confirmed under direct visualization.
The directional marker creates a unique streak artifact that reflects the orientation of the directional lead. There is a hyperdense symmetric streak artifact parallel to the axis of the directional marker and a symmetric hypodense dark band orthogonal to the marker. This is often sufficient to infer the direction of the marker. If not, it at least renders 2 opposite possibilities for the direction of the marker, which can then be easily reconciled by comparison with x-ray images.
We propose a method to determine orientation of directional DBS leads in a precise manner on conventional imaging and readily available software. This method is reliable across DBS vendors, and it can simplify this process and aid in effective programming.
定向电极因其能够引导电流并最大化治疗窗口，已在脑深部电刺激（DBS）中得到广泛应用。准确识别电极方向对于有效编程至关重要。尽管在二维成像上可以看到定向标记，但精确的方向可能难以解读。最近的研究提出了确定电极方向的方法，但这些方法涉及先进的术中成像和/或复杂的计算算法。我们的目标是开发一种使用传统成像技术和现成软件来精确可靠地确定定向电极方向的方法。
我们检查了接受来自3家供应商的定向电极进行DBS治疗的患者的术后薄层计算机断层扫描（CT）和X线片。使用市售的立体定向软件，我们定位电极并精确规划新的轨迹，使其与CT上可视化的电极精确重叠。我们使用轨迹视图在与电极正交的平面中定位定向标记，并检查条纹伪影。然后，我们通过获取与在直接可视化下确认的各种方向的3个不同电极正交的薄层CT图像，用体模CT模型验证了该方法。
定向标记产生独特的条纹伪影，反映了定向电极的方向。有一条与定向标记轴平行的高密度对称条纹伪影和一条与标记正交的对称低密度暗带。这通常足以推断标记的方向。如果不行，它至少给出标记方向的两种相反可能性，然后通过与X线图像比较可以很容易地确定。
我们提出了一种在传统成像和现成软件上精确确定定向DBS电极方向的方法。该方法在不同DBS供应商中都可靠，并且可以简化这一过程并有助于有效编程。
