Abstract
An examination is made of dipole location errors in electroencephalogram (EEG) source analysis, due to not incorporating the ventricular system (VS), omitting a hole in the skull and underestimating skull conductivity. The simulations are performed for a large number of test dipoles in 3D using the finite difference method. The maximum dipole location error encountered, utilising 27 and 53 electrodes is 7.6 mm and 6.1 mm, respectively when omitting the VS, 5.6 mm and 5.2 mm, respectively when neglecting the hole in the skull, and 33.4 mm and 28.0 mm, respectively when underestimating skull conductivity. The largest location errors due to neglecting the VS can be found in the vicinity of the VS. The largest location erros due to omitting a hole can be found in the vicinity of the hole. At these positions the fitted dipoles are found close to the hole. When skull conductivity is underestimated, the dipole is fitted close to the skull-brain border in a radial direction for all test dipoles. It was found that the location errors due to underestimating skull conductivity are typically higher than those found due to neglecting the VS or neglecting a hole in the skull.
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References
Ashburner, J., andFriston, K. (1997): ‘Multimodal image coregistration and partitioning—a unified framework’,Neuroimage,6, pp. 209–217
Awada, K. A., Jackson, D. R., Baumann, Stephen B., Williams, J. T., Wilton, D. R., Fink, P., andPrasky, B. (1998): ‘Effects of conductivity uncertainties and modeling errors on EEG source localization using a 2-D model’,IEEE Trans. Biomed. Eng.,45, pp. 1135–1145
Baumann, S., Wozny, D., Kelly, S., andMeno, F. (1997): ‘The electrical conductivity of human cerebrospinal fluid at body temperature,IEEE Trans. Biomed. Eng.,44, pp. 220–223
Boon, P., andD'Havé, M. (1995): ‘Interictal and ictal dipole modelling in patients with refractory partial epilepsy’,Acta Neurologica Scand.,92, pp. 7–18
Boon, P., D'Havé, M., Vonck, K., Baulac, M., Vandekerckhove, T. andDe Reuck, J. (1996): ‘Dipole modeling in epilepsy surgery candidates’,Epilepsia,38, pp. 208–218
Cuffin, B. N. (1993): ‘Effects of local variations in skull and scalp thickness on EEG's and MEG's’,IEEE Trans. Biomed. Eng.,40, pp. 42–48
Ebersolf, J. S., andWade, P. B. (1990): ‘Spike voltage topography and equivalent dipole localization in complex partial epilepsy’,Brain Topography,3, pp. 21–34
Haueisen, J., Ramon, C., Eiselt, M., Brauer, H., andNowak, H. (1997): ‘Influence of tissue resistivities on neuromagnetic fields and electric potentials studied with a finite element model of the head’,IEEE Trans. Biomed. Eng.,44, pp. 727–735
Huiskamp, G., Vroeijenstijn, M., van Dijk, R., Wieneke, G., andvan Huffelen, A. (1999): ‘The need for correct realistic geometry in the inverse EEG problem’,IEEE Trans. Biomed. Eng.,46, pp. 1281–1287
Jasper, H. (1958): ‘Report of committee on methods of clinical exam in EEG’,Electroencephalography Clin. Neurophysiol.,10, pp. 370–375
Laarne, P. H. E., Hyttinen, J., Suihko, V., andMalmivuo, J. (1995): ‘Validation of a detailed computer model for the electric fields in the brain’,J. Med. Eng. Technol.,19, pp. 84–87
Malmivuo, J., andPlonsey, R. (1995): ‘Bioelectromagnetism: principles and applications of bioelectric and biomagnetic fields’ (Oxford University Press, New York)
Matsuba, H., Vrba, J., andCheung, T. (1996): ‘Current dipole localization errors as a function of system noise and the number of sensors' in ‘Biomag96: Advances in Biomagnetism Research’ (Springer-Verlag). In press and available on url:www.ctf.com
Mitchell, A., andGriffiths, D. (1980): The finite difference method in partial differential equations’ (John Wiley and Sons)
Nelder, J. A., andMead, R. (1965): ‘A simplex method for function minimization’,Comput. J.,7, pp. 308–313
Niedermeyer, E., andLopes Da Silva, F. (1993): ‘Electrocephalography’ Williams and Wilkins Chapter 23
Ollikainen, J., Vauhkonen, M., Karjalainen, P., andKaipio, J. (1999): ‘Effects of local skull inhomogeneities on EEG source estimation’,Med. Eng. Phys.,21, pp. 143–154
Oostendorp, T., andDelbeke, J. (1999): ‘The conductivity of the human skull in vivo and in vitro’. Proc. 1st Joint BMES/EMBS Conf., p. 456
Pohemeier, R., Buchner, H., Knoll, G., Reinäcker, A., Beckmann, R., andPesh, J. (1997): ‘The influence of skull-conductivity misspecification on inverse source localization in realistically shaped finite element head models’,Brain Topography,9, pp. 157–162
Press, W. H., Teukolsky, S. A. Vetterling, W. T., andFlannery, B. P. (1995): ‘Numerical recipes in C' (Cambridge University Press)
Roth, B., Gorbach, A., andSato, S. (1993): ‘How well does a three-shell model predict positions of dipoles in a realistically shaped head?’,Electroencephalography Clin. Neurophysiol.,87, pp. 175–184
Rush, S., andDriscoll, D. A. (1969): ‘EEG electrode sensitivity—an application of reciprocity’,IEEE Trans. Biomed. Eng.,BME-16, pp. 15–22
Salu, Y., Cohen, L. G., Rose, D., Sato, S., Kufta, C., andHallett, M. (1990): ‘An improved method for localizing electric brain dipoles’,IEEE Trans. Biomed. Eng.,37, pp. 699–705
Schaul, N. (1998): ‘The fundamental neural mechanisms of electroencephalography’,Electroencephalography Clin. Neurophysiol.,106, pp. 101–107
van den Broek, S. (1997): ‘Volume conduction effects on EEG and MEG’. PhD thesis, University of Twente
van den Broek, S., Reinders, F., Donderwinkel, M., andPeeters M. (1998): ‘Volume conduction effects in EEG and MEG’,Electroencephalography Clin. Neurophysiol.,106, pp. 522–534
Van Hoey, G., Vanrumste, B., D'Havé, M., Van de Walle, R., Lemhieu, I., andBoon, P. (2000): ‘The influence of measurement noise and electrode mislocalisation on EEG dipole-source localisation’,Med. Biol. Eng. Comput.,38, pp. 287–296
Vanrumste, B., Van Hoey, G., Boon, P., D'Havé, M., andLemahieu, I. (1998): ‘Inverse calculations in EEG source analysis applying the finite difference method, reciprocity and lead fields’. Proc. 20th Ann. Int. Conf. IEEE Engineering in Medicine and Biology Society, Vol. 20, part 4/6, pp. 2112–2115, Hong Kong
Vanrumste, B., Van Hoey, G., Van de Walle, R., D'Havé, M., Lemahieu, I., andBoon, P. (2000): ‘Localization errors due to noise versus localization errors due to the 3-shell spherical head model’. Proc. 3rd Int. Conf. Bioelectromagnetism. Accepted for publication, in press
Yvert, B., Bertrand, O., Thévenet, M., Echallier, J. F., andPernier, J. (1997): ‘A systematic evaluation of the spherical model accuracy in EEG dipole localization’,Electroencephalography Clin. Neurophysiol.,102, pp. 452–459
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Vanrumste, B., Van Hoey, G., Van de Walle, R. et al. Dipole location errors in electroencephalogram source analysis due to volume conductor model errors. Med. Biol. Eng. Comput. 38, 528–534 (2000). https://doi.org/10.1007/BF02345748
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DOI: https://doi.org/10.1007/BF02345748