A fiducial skull marker for precise MRI-based stereotaxic surgery in large animal models.
BACKGROUND
Stereotaxic neurosurgery in large animals is used widely in different sophisticated models, where precision is becoming more crucial as desired anatomical target regions are becoming smaller. Individually calculated coordinates are necessary in large animal models with cortical and subcortical anatomical differences.


NEW METHOD
We present a convenient method to make an MRI-visible skull fiducial for 3D MRI-based stereotaxic procedures in larger experimental animals. Plastic screws were filled with either copper-sulfate solution or MRI-visible paste from a commercially available cranial head marker. The screw fiducials were inserted in the animal skulls and T1 weighted MRI was performed allowing identification of the inserted skull marker.


RESULTS
Both types of fiducial markers were clearly visible on the MRÍs. This allows high precision in the stereotaxic space.


COMPARISON WITH EXISTING METHOD
The use of skull bone based fiducial markers gives high precision for both targeting and evaluation of stereotaxic systems. There are no metal artifacts and the fiducial is easily removed after surgery.


CONCLUSION
The fiducial marker can be used as a very precise reference point, either for direct targeting or in evaluation of other stereotaxic systems.
['Glud|Andreas Nørgaard|AN|', 'Bech|Johannes|J|', 'Tvilling|Laura|L|', 'Zaer|Hamed|H|', 'Orlowski|Dariusz|D|', 'Fitting|Lise Moberg|LM|', 'Ziedler|Dora|D|', 'Geneser|Michael|M|', 'Sangill|Ryan|R|', 'Alstrup|Aage Kristian Olsen|AKO|', 'Bjarkam|Carsten Reidies|CR|', 'Sørensen|Jens Christian Hedemann|JCH|']
D000818:Animals D019327:Copper Sulfate D057918:Fiducial Markers D021621:Imaging, Three-Dimensional D008279:Magnetic Resonance Imaging D023421:Models, Animal D012886:Skull D013238:Stereotaxic Techniques D013552:Swine
Stereotaxic surgery Functional neurosurgery Göttingen minipig MRI-compatible surgery Pig