Uhl Eberhard, Zausinger Stefan, Morhard Dominik, Heigl Thomas, Scheder Benjamin, Rachinger Walter, Schichor Christian, Tonn Jörg-Christian
Department of Neurosurgery, Klinikum Grosshadern, University of Munich, Munich, Germany. eberhard.uhl@ lkh- klu.at
Neurosurgery. 2009 May;64(5 Suppl 2):231-9; discussion 239-40. doi: 10.1227/01.NEU.0000340785.51492.B5.
We report our preliminary experience in a prospective series of patients with regard to feasibility, work flow, and image quality using a multislice computed tomographic (CT) scanner combined with a frameless neuronavigation system (NNS).
A sliding gantry 40-slice CT scanner was installed in a preexisting operating room. The scanner was connected to a frameless infrared-based NNS. Image data was transferred directly from the scanner into the navigation system. This allowed updating of the NNS during surgery by automated image registration based on the position of the gantry. Intraoperative CT angiography was possible. The patient was positioned on a radiolucent operating table that fits within the bore of the gantry. During image acquisition, the gantry moved over the patient. This table allowed all positions and movements like any normal operating table without compromising the positioning of the patient. For cranial surgery, a carbon-made radiolucent head clamp was fixed to the table.
Experience with the first 230 patients confirms the feasibility of intraoperative CT scanning (136 patients with intracranial pathology, 94 patients with spinal lesions). After a specific work flow, interruption of surgery for intraoperative scanning can be limited to 10 to 15 minutes in cranial surgery and to 9 minutes in spinal surgery. Intraoperative imaging changed the course of surgery in 16 of the 230 cases either because control CT scans showed suboptimal screw position (17 of 307 screws, with 9 in 7 patients requiring correction) or that tumor resection was insufficient (9 cases). Intraoperative CT angiography has been performed in 7 cases so far with good image quality to determine residual flow in an aneurysm. Image quality was excellent in spinal and cranial base surgery.
The system can be installed in a preexisting operating environment without the need for special surgical instruments. It increases the safety of the patient and the surgeon without necessitating a change in the existing surgical protocol and work flow. Imaging and updating of the NNS can be performed at any time during surgery with very limited time and modification of the surgical setup. Multidisciplinary use increases utilization of the system and thus improves the cost-efficiency relationship.
我们报告了一系列前瞻性患者使用多层计算机断层扫描（CT）扫描仪结合无框架神经导航系统（NNS）的初步经验，内容涉及可行性、工作流程和图像质量。
在一个现有的手术室中安装了一台滑环式40层CT扫描仪。该扫描仪与基于红外线的无框架NNS相连。图像数据直接从扫描仪传输到导航系统。这使得在手术过程中能够基于机架位置通过自动图像配准来更新NNS。术中CT血管造影成为可能。患者被安置在一个可透射线的手术台上，该手术台可放入机架的孔腔内。在图像采集过程中，机架在患者上方移动。这张手术台允许进行像任何普通手术台一样的所有体位摆放和移动，而不会影响患者的体位。对于颅脑手术，一个碳制的可透射线头夹固定在手术台上。
对前230例患者的经验证实了术中CT扫描的可行性（136例颅内病变患者，94例脊柱病变患者）。经过特定的工作流程，颅脑手术中因术中扫描而导致的手术中断可限制在10至15分钟，脊柱手术中可限制在9分钟。在230例病例中的16例，术中成像改变了手术进程，原因要么是对照CT扫描显示螺钉位置欠佳（307枚螺钉中有17枚，7例患者中有9例需要校正），要么是肿瘤切除不充分（9例）。到目前为止，已对7例患者进行了术中CT血管造影，图像质量良好，用于确定动脉瘤中的残余血流。脊柱和颅底手术中的图像质量极佳。
该系统可以安装在现有的手术环境中，无需特殊的手术器械。它提高了患者和外科医生的安全性，而无需改变现有的手术方案和工作流程。在手术过程中的任何时候都可以进行NNS的成像和更新，对手术设置的时间和改动非常有限。多学科使用提高了系统的利用率，从而改善了成本效益关系。
