A new mobile and light-weight navigation system for interventional radiology

In interventional pain therapy, the goal is to place a needle near spinal nerves in order to locally apply pharmaceutical substances. We propose a navigation system that consists only of a small tablet PC, a navigation camera and trackers. The system is small, light-weighted, cost-effective and easy to setup. It allows for ergonomic work outside of the gantry and provides guidance even when the trajectory is oblique to the acquired CT slices. The system was tested in a clinical environment using a plastic vertebra as spine phantom. Two spots (Beekley) were attached as target points. The vertebra was embedded in wax gel which mimics the properties of skin and tissue. Four artificial landmarks were attached to the wax surface for point-to-point registration. During the intervention, the position of the needle was displayed in the image data. When the axis of the needle hit the target, it was displayed green, else red. With a 100-mm needle, the distance between the needle tip and the target point was below 5 mm. The integration of the system into the clinical workflow posed no problems. Setup time of the system included connecting the camera to the system took less than 2 min.