Rajon Didier A, Bova Frank J, Bhasin R Rick, Friedman William A
Neurosurgery Department, University of Florida, Gainesville, Florida 32610, USA.
J Appl Clin Med Phys. 2006 Nov 28;7(4):81-98. doi: 10.1120/jacmp.v7i4.2302.
Image-guided surgery can be broken down into two broad categories: frame-based guidance and frameless guidance. In order to reduce both the invasive nature of stereotactic guidance and the cost in equipment and time, we have developed a new guidance technique based on rapid prototyping (RP) technology. This new system first builds a computer model of the patient anatomy and then fabricates a physical reference frame that provides a precise and unique fit to the patient anatomy. This frame incorporates a means of guiding the surgeon along a preplanned surgical trajectory. This process involves (1) obtaining a high-resolution CT or MR scan, (2) building a computer model of the region of interest, (3) developing a surgical plan and physical guide, (4) designing a frame with a unique fit to the patient's anatomy with a physical linkage to the surgical guide, and (5) fabricating the frame using an RP unit. Software was developed to support these processes. To test the accuracy of this process, we first scanned and reproduced a plastic phantom fabricated to validate the system's ability to build an accurate virtual model. A target on the phantom was then identified, a surgical approach planned, a surgical guide designed, and the accuracy and precision of guiding a probe to that target were determined. Steps 1 through 5 were also evaluated using a head phantom. The results show that the RP technology can replicate an object from CT scans with submillimeter resolution. The fabricated reference frames, when positioned on the surface of the phantom and used to guide a surgical probe, can position the probe tip with an accuracy of 1.7 mm at the probe tip. These results demonstrate that the RP technology can be used for the fabrication of customized positioning frames for use in image-guided surgery.
基于框架的引导和无框架引导。为了降低立体定向引导的侵入性以及设备和时间成本，我们基于快速成型（RP）技术开发了一种新的引导技术。这种新系统首先构建患者解剖结构的计算机模型，然后制造一个物理参考框架，该框架能精确且独特地贴合患者解剖结构。这个框架包含一种沿着预先规划的手术轨迹引导外科医生的方法。这个过程包括：（1）获取高分辨率CT或MR扫描图像；（2）构建感兴趣区域的计算机模型；（3）制定手术计划并设计物理导向器；（4）设计一个与患者解剖结构独特贴合且与手术导向器有物理连接的框架；（5）使用RP设备制造框架。我们开发了软件来支持这些过程。为了测试这个过程的准确性，我们首先扫描并复制了一个制造好的塑料模型，以验证系统构建精确虚拟模型的能力。然后在模型上确定一个靶点，规划一种手术入路，设计一个手术导向器，并确定将探针导向该靶点的准确性和精度。我们还使用头部模型对步骤1至5进行了评估。结果表明，RP技术能够以亚毫米级分辨率从CT扫描中复制物体。制造好的参考框架放置在模型表面并用于引导手术探针时，能将探针尖端定位在距靶点1.7毫米的精度范围内。这些结果表明，RP技术可用于制造定制的定位框架，用于图像引导手术。
