Accuracy of flat panel detector CT with integrated navigational software with and without MR fusion for single-pass needle placement

How to iGuide: flat panel detector, CT-assisted, minimally invasive evacuation of intracranial hematomas

Evidence is growing to support minimally invasive surgical evacuation of intraparenchymal hematomas, particularly those with minimal residual hematoma volumes following evacuation. To maximize the potential for neurologic recovery, it is imperative that the trajectory for access to the hematoma minimizes disruption of normal parenchyma. Flat panel detector CT-based navigation and needle guidance software provides a platform that uses flat panel detector CT imaging obtained on the angiography table to aid reliable and safe access to the hematoma. In addition to providing a high degree of accuracy, this method also allows convenient and rapid re-imaging to assess navigation accuracy and the degree of hematoma evacuation prior to procedural completion. We provide a practical review of the syngo iGuide needle guidance software and the methodology for incorporating its use, and the software of other vendors, in a variety of minimally invasive methods for evacuation of intraparenchymal hematomas.

Accuracy of image-guided percutaneous injection into a phantom spinal cord utilizing flat panel detector CT with MR fusion and integrated navigational software

PURPOSE

To evaluate the accuracy of percutaneous fluoroscopic injection into the spinal cord of a spine phantom utilizing integrated navigational guidance from fused flat panel detector CT (FDCT) and MR datasets. Conventional and convection-enhanced delivery (CED) techniques were evaluated.

MATERIALS AND METHODS

FDCT and MR datasets of a swine thoracic spine phantom were co-registered using an integrated guidance system and surface to spinal cord target trajectory planning was performed on the fused images. Under real-time fluoroscopic guidance with pre-planned trajectory overlay, spinal cord targets were accessed via a coaxial technique. Final needle tip position was compared with a pre-determined target on 10 independent passes. In a subset of cases, contrast was injected into the central spinal cord with a 25G spinal needle or customized 200 µm inner diameter step design cannula for CED.

RESULTS

Average needle tip deviation from target measured 0.92±0.5 mm in the transverse, 0.47±0.4 mm in the anterior-posterior, and 1.67±1.2 mm in the craniocaudal dimension for an absolute distance error of 2.12±1.12 mm. CED resulted in elliptical intramedullary diffusion of contrast compared with primary reflux observed with standard needle injection.

CONCLUSIONS

These phantom feasibility data demonstrate a minimally invasive percutaneous approach for targeted injection into the spinal cord utilizing real-time fluoroscopy aided by overlay trajectories derived from fused MRI and FDCT data sets with a target error of 2.1 mm. Intramedullary diffusion of injectate in the spinal cord is facilitated with CED compared with standard injection technique. Pre-clinical studies in large animal models are warranted.

Feasibility of laser-guided percutaneous pedicle screw placement in the lumbar spine using a hybrid-OR

PURPOSE

Innovations in intraoperative imaging lead to major changes in orthopaedic surgery. In our setting, a 3D flat-panel c-arm (Artis zeego) is mounted on a robotic arm offering an integrated aiming tool (Syngo iGuide). Our aim was to investigate the feasibility of Syngo iGuide for pedicle screw placement in comparison with fluoroscopic screw implantation.

METHODS

In 10 lumbar models, 100 screws were implanted. In 5 models, a standard fluoroscopic technique was used. Syngo iGuide was used in all other models. Afterwards, CT-scans were performed and screw accuracy was investigated.

RESULTS

The procedure time for the new technique was significantly longer in comparison with the standard technique. The post-operative CT showed the same accuracy in both groups.

CONCLUSIONS

Syngo iGuide proofed feasible for percutaneous implantation of pedicle screws in anatomic models. Syngo iGuide can be a help for screw implantation in difficult anatomic regions without the need of an additional navigation system.