Computed Tomography-Ultrasound Fusion for spine surgery
Computed Tomography (CT) based navigation is rapidly becoming the standard of care in spinal surgery. While CT provides excellent bony detail, it is quite limited in its ability to discern soft tissues. Intra-procedural ultrasound (US) can provide real-time soft tissue discrimination allowing the delineation of tumor tissue, discs and neural elements, which is particularly useful for minimally invasive surgery. Challenges exist with application of US in the spine with respect to spinal level and orientation determination.
We have developed a spine-focused surgical workflow allowing for interchangeable US probes and navigation systems. Our technology uses the 3D Slicer open source platform for rapid development of image visualization and navigation solutions. We tested our technology with both Phillips and Telmed US systems, and a Medtronic StealthStation S7 for optical tracking.
The interface shows in real-time: 3D view of US plane with a rendering of the anatomy, US Image, corresponding CT image plane and fused image. Accuracy (mm) of the system was established by identifying features on the vertebral body in both modalities.
Our spine surgery workflow allows US-CT fusion intra-operatively, simultaneously displaying hard and soft tissue information, using various combinations of US systems. Accurate localization enables the utilization of navigation to guide soft tissue resection in places that are difficult to visualize (i.e. in thoracic discectomy or assessing the adequacy of a dorsal decompression during a cervical laminectomy for myelopathy).
US Plane in 3D CT rendering.
US Plane.
CT Plane.
US – CT Fusion.
