Article
Neuronavigation guided by intraoperative 3D ultrasound
Intraoperativer Einsatz von 3D-Ultraschall in der Neuronavigation
Search Medline for
Authors
Published: | May 8, 2006 |
---|
Outline
Text
Objective: Ultrasound is a cost effective intraoperative imaging modality used frequently. It has been used in combination with neuronavigation as an alternative to intraoperative magnetic resonance imaging (MRI). 3-D ultrasound technology can solve the orientation problem experienced previously with two-dimensional ultrasound. So-called Two-platform solutions tend to prolong operative time due to the calibration procedure. A novel operative image guided system overcomes this disadvantage and provides 3D ultrasound images.
Methods: The new ultrasound system (IGSonic) is integrated into a neuronavigation system (VectorVision2, BrainLAB, Germany). A precalibrated tracking array is attached to the probe and allows tracking the position of the ultrasound image plane. We have used intraoperative 3-D ultrasound data acquisition for four patients with brain tumours. The acquisition time was 1-2 minutes each and calculation time was 30 – 60 seconds. Acquisition was only triggered at points with no information. 256 slices were collected per data set and ultrasound data was reconstructed based on spatial resolution. 3D-ultrasound was fused to preoperative data via a registration and reference coordinate system, no coregistration was necessary.
Results: The system worked properly during all procedures. It displays a reconstruction view of 3D-ultrasound (axial, sagittal, coronal) and live ultrasound in combination with the preoperatively acquired neuronavigational data (CT or MRI). It provides intraoperative image updating for a maximum of 10 sets. Intraoperative 3-D ultrasound represents a possible solution for the problem of brain shift in neuronavigation, because it gives an instant and updated three-dimensional orientation as well as an accurate map of the patient's true anatomy at various stages of the operation.
Conclusions: 3D-ultrasound provides online information on the progress of surgery and displays the pre- or intraoperatively acquired information, such as labelled points, trajectories or objects. Intraoperative 3D-ultrasound acquisition for neuronavigation might also be used without preoperatively acquired neuronavigational data.