Aldabek Dirar, Hodul Andreas, Alesch François
Department of Neurosurgery, Heinrich-Braun-Klinikum, Karl-Keil-Straße 35, 08060, Zwickau, Germany.
Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
Acta Neurochir (Wien). 2025 Apr 2;167(1):96. doi: 10.1007/s00701-025-06505-8.
Pre- and postoperative imaging constitutes a firm brick in planning and steering accurate stereotactic procedures. The availability of intraoperative control measures, e.g., CT, MRI, and microelectrode recording (MER), is often limited to a minority of centers. Our approach utilizes fluoroscopy for target planning and coordinates validation as control.
This technique was primarily conceived for the RM (Riechert Mundinger) stereotactic system, but it also applies to the ZD (Zamorano-Dujovny) system. In the present study, we shifted the zero of the Z-value (axis of the patient) to + 60 mm. This corresponds to the center of the Angio/X-ray localizing plates. By assigning a radiopaque marker to the center of each plate, aligning these centers produced orthogonal and non-distorted stereotactic space. In this space, the magnification variable matters to us the most. Using available viewer software, we printed a millimetric grid on translucent foils with the corresponding magnification factor, which can easily be superimposed on the fluoroscopic image. This allows the precise validation of the coordinates of points of interest, including typical stereotactic landmarks. This technique can be used in both views, AP and lateral.
We have validated this technique under non-clinical (phantom) conditions and with intraoperative images obtained during routine stereotactic procedures. The latter were acquired using our classical stereotactic fixedly-mounted X-ray system. We found identical results, with an accuracy margin of error lower than 1 mm.
This simple geometrical adaptation proved to be an accurate, accessible, mobile, and manageable technique providing immediate access to stereotactic coordinates during surgery. The accuracy proved to be non-inferior to other more complex and time-consuming imaging modalities.
术前和术后成像在规划和指导精确的立体定向手术中起着坚实的基础作用。术中控制措施，如CT、MRI和微电极记录（MER），通常仅在少数中心可用。我们的方法利用荧光透视进行靶点规划和坐标验证作为控制手段。
该技术最初是为RM（里歇特·蒙丁格）立体定向系统设计的，但也适用于ZD（萨莫拉诺-杜乔夫尼）系统。在本研究中，我们将Z值（患者轴线）的零点移至 +60 mm。这对应于血管造影/X射线定位板的中心。通过在每个板的中心放置一个不透射线的标记物，将这些中心对齐可产生正交且无畸变的立体定向空间。在这个空间中，放大倍数变量对我们最为重要。使用可用的观察软件，我们在半透明箔片上打印了具有相应放大倍数的毫米网格，该网格可以轻松叠加在荧光透视图像上。这使得能够精确验证感兴趣点的坐标，包括典型的立体定向标志。该技术可用于前后位（AP）和侧位两种视图。
我们已在非临床（模型）条件下以及在常规立体定向手术期间获得的术中图像中验证了该技术。后者是使用我们经典的立体定向固定安装X射线系统获取的。我们发现结果相同，误差精度范围低于1毫米。
这种简单的几何调整被证明是一种准确、可及、灵活且易于管理的技术，在手术过程中能够立即获取立体定向坐标。其准确性被证明不低于其他更复杂且耗时的成像方式。
