Ji Songbai, Fan Xiaoyao, Paulsen Keith D, Roberts David W, Mirza Sohail K, Lollis S Scott
IEEE Trans Biomed Eng. 2015 Sep;62(9):2177-86. doi: 10.1109/TBME.2015.2415731. Epub 2015 Mar 26.
Despite its widespread availability and success in open cranial neurosurgery, image-guidance technology remains more limited in use in open spinal procedures, in large part, because of patient registration challenges. In this study, we evaluated the feasibility of using intraoperative stereovision (iSV) for accurate, efficient, and robust patient registration in an open spinal fusion surgery. Geometrical surfaces of exposed vertebrae were first reconstructed from iSV. A classical multistart registration was then executed between point clouds generated from iSV and preoperative computed tomography images of the spine. With two pairs of feature points manually identified to facilitate the registration, an average registration accuracy of 1.43 mm in terms of surface-to-surface distance error was achieved in eight patient cases using a single iSV image pair sampling 2-3 vertebral segments. The iSV registration error was consistently smaller than the conventional landmark approach for every case (average of 2.02 mm with the same error metric). The large capture ranges (average of 23.8 mm in translation and 46.0° in rotation) found in the iSV patient registration suggest the technique may offer sufficient robustness for practical application in the operating room. Although some manual effort was still necessary, the manually-derived inputs for iSV registration only needed to be approximate as opposed to be precise and accurate for the manual efforts required in landmark registration. The total computational cost of the iSV registration was 1.5 min on average, significantly less than the typical ∼30 min required for the landmark approach. These findings support the clinical feasibility of iSV to offer accurate, efficient, and robust patient registration in open spinal surgery, and therefore, its potential to further increase the adoption of image guidance in this surgical specialty.
尽管图像引导技术在开放性颅脑神经外科手术中已广泛应用且取得成功，但在开放性脊柱手术中的应用仍较为有限，这在很大程度上是由于患者配准方面存在挑战。在本研究中，我们评估了在开放性脊柱融合手术中使用术中立体视觉（iSV）进行准确、高效且可靠的患者配准的可行性。首先从iSV重建暴露椎体的几何表面。然后在由iSV生成的点云与脊柱术前计算机断层扫描图像之间执行经典的多起点配准。通过手动识别两对特征点以促进配准，在8例患者中，使用单个iSV图像对采样2 - 3个椎体节段，实现了表面到表面距离误差平均为1.43毫米的配准精度。在每个病例中，iSV配准误差始终小于传统的地标方法（相同误差度量下平均为2.02毫米）。iSV患者配准中发现的较大捕获范围（平移平均为23.8毫米，旋转平均为46.0°）表明该技术可能为手术室中的实际应用提供足够的鲁棒性。尽管仍需要一些人工操作，但与地标配准所需的精确和准确的人工操作相比，iSV配准的人工输入仅需近似值。iSV配准的总计算成本平均为1.5分钟，明显少于地标方法通常所需的约30分钟。这些发现支持了iSV在开放性脊柱手术中提供准确、高效且可靠的患者配准的临床可行性，因此，它有可能进一步提高该外科专业中图像引导技术的应用率。
