Preliminary results of nonfluoroscopy-based 3D navigation for neurointerventional procedures.
OBJECTIVE
To investigate the capabilities of a neurovascular navigation prototype in phantom experiments.


METHODS
The proposed navigation system integrates three-dimensional (3D) visualization of the anatomy and real-time electromagnetic localization of the endovascular tools. A 3D model of an endovascular phantom was reconstructed from thresholded preprocedural computed tomographic (CT) data. The vascular model was aligned with the reference frame of an electromagnetic tracker by using paired-point matching based on eight external fiducials. The robustness and accuracy of the registration were evaluated in 29 experiments. A magnetically tracked catheter was inserted into the carotid artery of the phantom, and the navigation system was used to reach five predefined vascular landmarks. The spatial accuracy of the prototype was evaluated during 50 endovascular targeting attempts.


RESULTS
The navigation system achieved accurate co-registration of the location of a catheter inside a 3D reconstruction of a phantom vasculature. The experiments demonstrated the robustness of the registration, with a standard deviation for the translation and rotation components of 0.7 mm and 0.3 degrees , respectively. The maximal average error on the fiducials was 3.2 mm. Endovascular navigation by using the 3D real-time display was successfully performed with a mean overall accuracy of 2.7 mm +/- 0.7 and no projection limitation.


CONCLUSIONS
The authors developed a navigation system that provides real-time 3D visualization of the position of endovascular components in a neurovascular phantom. The preliminary in vitro experiments showed clinically acceptable accuracy.
Pujol
Sonia
S
Laboratory of Mathematics in Imaging, Harvard Medical School, Boston, Mass., USA. spujol@bwh.harvard.edu
Frerichs
Kai
K
Norbash
Alexander
A
Kikinis
Ron
R
Westin
Carl-Fredrik
CF
D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging; D003198:Computer Simulation; D055590:Electromagnetic Phenomena; D006801:Humans; D021621:Imaging, Three-Dimensional; D008954:Models, Biological; D019047:Phantoms, Imaging; D015641:Radiography, Interventional / Q000379:methods*; D014057:Tomography, X-Ray Computed