gms | German Medical Science

56. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)
3èmes journées françaises de Neurochirurgie (SFNC)

Deutsche Gesellschaft für Neurochirurgie e. V.
Société Française de Neurochirurgie

07. bis 11.05.2005, Strasbourg

Is fiber tract mapping with diffusion tensor MRI accurate enough for neurosurgical procedures?

Ist die Faserbahnabgrenzung im Diffusions-Tensor MRT für neurochirurgische Anwendungen präzise genug?

Meeting Abstract

  • corresponding author U. Bürgel - Department of Neurosurgery, University Hospital, RWTH, Aachen
  • K. Amunts - Institute of Medicine, Research Center Jülich, Jülich
  • F. Schoth - Department of Neuroradiology, University Hospital, RWTH, Aachen
  • J. Gilsbach - Department of Neurosurgery, University Hospital, RWTH, Aachen

Deutsche Gesellschaft für Neurochirurgie. Société Française de Neurochirurgie. 56. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3èmes journées françaises de Neurochirurgie (SFNC). Strasbourg, 07.-11.05.2005. Düsseldorf, Köln: German Medical Science; 2005. DocP007

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dgnc2005/05dgnc0275.shtml

Published: May 4, 2005

© 2005 Bürgel et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

Text

Objective

Fiber tract mapping with DTI is becoming popular for planning neurosurgical approaches and intraoperative neuronavigation. Although an increasing number of studies deal with DTI techniques or neuronal connectivity, there is no proof as to how far DTI corresponds with “real” fiber anatomy. DTI, however, does not directly render the anatomy but reflects a functional condition and it can be susceptible to artifacts, e.g., in pathologically altered brains. Therefoer, we analyzed the accuracy of fiber tract anatomy in DTI by comparing the optic radiation (OR) and corticospinal tract (CT) as delineated in vivo with the tracts as mapped in histological sections of postmortem brains.

Methods

10 human brains were serially sectioned, myelin stained and digitized. In the digitized sections, the tracts were delineated. The image series were 3-D reconstructed and the volume files were linearly and nonlinearly warped to a stereotactic reference space of an in vivo MR-standard brain. The individual fiber tracts were superimposed, and probability maps were generated as a quantitative measure of intersubject variability. DTI scans and high resolution T1 weighted 3-D sequences were obtained in 10 healthy adults. The fiber tracts were identified in each section on the basis of anatomical landmarks, e.g., lateral ventricles (LV), calcarine sulcus, precentral gyrus, internal capsule (IC) and the diffusion images. Finally, the DTI data were warped to the same standard space, and probability maps were calculated.

Results

Comparing the histological map with the DTI probability maps indicates a similar distribution of variability. E.g., variability of the OR is high below the cortical surface and the overlap increases on its course lateral to the LV towards the temporal isthmus. The superimposition of the histological and DTI maps enabled a quantification of the accuracy of the DTI-based mapping: The proportion of the DTI-volumes became more similar to the histological volumes with increasing level of overlap (e.g., the CT in the IC). In defined regions the fiber tracts in DTI „hit“ the histological tract in all probability with an accordanceof up to 90%.

Conclusions

This study shows that DTI- based mapping of the OR and CT is quite precise and fits well with the histology, the present “gold-standard” concerning spatial and grey-value resolution. For clinical routine, interactive fiber tract delineation is time- consuming and only in rare cases does it reveal new aspects which make a change in the surgical proceeding necessary.