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55. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)
1. Joint Meeting mit der Ungarischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

25. bis 28.04.2004, Köln

Error in indirect stereotactic target planning with MRI caused by frame positioning

Ausmaß der Fehler stereotaktischer indirekter Zielpunktplanung durch verkippte Positionierung des stereotaktischen Ringes

Meeting Abstract

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  • corresponding author Peter Herzog - Klinikum Augsburg, Neurochirurgische Klinik, Augsburg
  • H. Aldebert - Melanchthon-Gymnasium, Nürnberg
  • M. Bittl - Department of Neurological Surgery, University of Virginia, Charlottesville /USA

Deutsche Gesellschaft für Neurochirurgie. Ungarische Gesellschaft für Neurochirurgie. 55. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 1. Joint Meeting mit der Ungarischen Gesellschaft für Neurochirurgie. Köln, 25.-28.04.2004. Düsseldorf, Köln: German Medical Science; 2004. DocDI.06.07

The electronic version of this article is the complete one and can be found online at:

Published: April 23, 2004

© 2004 Herzog et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.




Some targets in functional neurosurgery can not be visualized in imaging studies. Their coordinates are determined by their previously established relative position to well defined landmarks. Generally the position of the stereotactic frame is assumed to be parallel to the anatomical coordinate system of the brain. We examined the deviation of the target points caused by angles between the frame coordinate system and the anatomical coordinate system.


In 49 of our patients who underwent functional procedures the Radionics MRI compatible UCLF frame was placed. It was our goal to position the frame parallel to the AC-PC axis and its vertical axis parallel to the falx and septum pelucidum. In the stereotactic MRI images coordinates for AC, PC and points in the falx and septum pelucidum were determined. With these reference points, using vector-mathematical procedures for coordinate transformation in all geometrical axis, the deviation between the anatomical and the frame coordinate system could be determined. The resulting corrections for the coordinates for the target STN were recorded.


The distances between the coordinates for the corrected and uncorrected targets were from 0.3 to 4 mm (median 1.7 mm) for the left STN. In 40% of cases the distance was greater or equal than 2 mm and in 6% greater or equal than 4 mm. The deviation for the right STN was similar.


The error occurring in indirect stereotactic target planning can lead to missing the anatomical target in a considerable number of cases. Appropriate steps should be taken to correct for errors occurring through deviation of frame and anatomical coordinate systems due to frame placement.