Department of Craniomaxillofacial Surgery, Hannover Medical School, Hannover, Germany.
Int J Med Robot. 2013 Sep;9(3):e39-45. doi: 10.1002/rcs.1444. Epub 2012 Jun 28.
As a prerequisite in navigation-assisted surgery, a three-dimensional image data set with registration marker is necessary. Often patients are presented, not being aware of facing a computer-assisted surgical intervention (CAS), with an already performed computed tomography (CT) data set without marker. The aim of this study was to evaluate the accuracy of a new method which allows performing CAS by enhancing the initial markerless data set with a marked subvolume gained by cone beam (CBCT) scan.
Therefore four registration markers are inserted and afterwards the patient is strongly limited to the field of interest scanned by CBCT scan (marked data set). Superimposed with the initial data set, a data set with reference markers and with full information is obtained. Registration procedure was performed with group A (25 patients, superimposed marked CBCT scan) and group B (25 patients, initially marked CT scan) using BrainLab® navigation by two observers and overall system accuracy was measured using the registration landmarks and additional intraoperative landmarks (tooth cusps).
Adequate image quality assumed, no significant difference between group A and B was detected. Enhancing an initially performed data set with registration marker by using a marked subvolume could improve the workflow for navigation-assisted surgery due to the availability of cone beam scan technology, provide excellent resolution with reduced metal artifacts nearby dental restorations, and reduce radiation dose for the patient.
Regarding the advantages of the new method which allows performing CAS by enhancing the initial markerless data set with a marked subvolume gained by cone beam (CBCT) scan, this technique will play a major part in navigation-assisted surgery and will address widespread general methodological solutions that are of great interest in multidisciplinary treatment.
作为导航辅助手术的前提，需要有一个带有注册标记的三维图像数据集。通常情况下，患者并不知道自己将面临计算机辅助手术干预（CAS），而只是提供已经完成的无标记计算机断层扫描（CT）数据集。本研究的目的是评估一种新方法的准确性，该方法通过增强初始无标记数据集来实现 CAS，具体方法是使用锥形束 CT（CBCT）扫描获得标记的子体积。
因此，插入四个注册标记，然后将患者强烈限制在 CBCT 扫描（标记数据集）扫描的感兴趣区域内。与初始数据集叠加，获得具有参考标记和完整信息的数据集。使用 BrainLab®导航，由两名观察者对组 A（25 名患者，叠加标记的 CBCT 扫描）和组 B（25 名患者，初始标记的 CT 扫描）进行注册程序，并用注册标记和额外的术中标记（牙尖）测量总体系统准确性。
在假设适当的图像质量的情况下，未发现组 A 和组 B 之间存在显著差异。通过使用标记的子体积增强初始执行的数据集，由于锥形束扫描技术的可用性，可以改善导航辅助手术的工作流程，提供出色的分辨率，减少附近牙科修复体的金属伪影，并降低患者的辐射剂量。
鉴于通过增强初始无标记数据集来实现 CAS 的新方法的优势，该技术将在导航辅助手术中发挥重要作用，并解决多学科治疗中非常感兴趣的广泛的一般方法学解决方案。
