Advanced

AJNR - American Journal of Neuroradiology

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Rodrigo, S. Articles by Meder, J.F. Search for Related Content PubMed PubMed Citation Articles by Rodrigo, S. Articles by Meder, J.F.

American Journal of Neuroradiology 28:1526-1531, September 2007
DOI 10.3174/ajnr.A0584
© 2007 American Society of Neuroradiology

FUNCTIONAL

Human Subinsular Asymmetry Studied by Diffusion Tensor Imaging and Fiber Tracking

S. Rodrigo^a,b, O. Naggara^a, C. Oppenheim^a,b,c, N. Golestani^b,c, C. Poupon^b, Y. Cointepas^b, J.F. Mangin^b, D. Le Bihan^b and J.F. Meder^a

^a Département d'Imagerie Morphologique et Fonctionnelle, Faculté de Médecine, Université Paris-Descartes, Centre Hospitalier Sainte-Anne, Paris, France
^b Unité de Neuro-Imagerie Anatomo-Fonctionnelle, Service Hospitalier Frederic Joliot, CEA, Orsay, France
^c INSERM U 562, Cognitive Neuroimaging, Service Hospitalier Frederic Joliot, CEA, Orsay, France

Please address correspondence to Catherine Oppenheim, MD, PhD, Département d'Imagerie Morphologique et Fonctionnelle, Centre Hospitalier Sainte-Anne, 1 rue Cabanis, 75674 Paris cedex 14, France; e-mail: c.oppenheim{at}ch-sainte-anne.fr

BACKGROUND AND PURPOSE: Our aim was to improve our understanding of the subinsular white matter microstructural asymmetries in healthy right-handed subjects. Structural brain asymmetries could be related to functional asymmetries such as hemisphere language dominance or handedness. Besides the known gray matter asymmetries, white matter asymmetries could also play a key role in the understanding of hemispheric specialization, notably that of language.

MATERIALS AND METHODS: White matter asymmetries were studied by diffusion tensor imaging at 1.5T (41 diffusion-gradient directions; b-value set to 700 s/mm²; matrix, 128²; in-plane resolution, 1.875 x 1.875 mm; section thickness, 2.0 mm) and fiber tracking (BrainVISA software). The main white matter bundles passing through the subinsular area were segmented, and fractional anisotropy (FA) was measured along each of the segmented bundles.

RESULTS: In line with published results, we found an asymmetry of the arcuate fasciculus and the subinsular white matter, namely left-greater-than-right FA in right-handed controls. Furthermore, by segmenting major tracts coursing through this region, we showed that the subinsular portions of the uncinate fasciculus (UF) and the inferior occipitofrontal fasciculus (IOF) contribute to this FA asymmetry. Those tracts have been reported to be likely implicated in the language network.

CONCLUSION: Because the left hemisphere hosts language functions in most right-handers, the significant leftward asymmetry observed within the arcuate fasciculus, the subinsular part of the UF and IOF may be related to the hemispheric specialization for language.

This article has been cited by other articles:

				M.E. Ahmadi, D.J. Hagler Jr, C.R. McDonald, E.S. Tecoma, V.J. Iragui, A.M. Dale, and E. Halgren Side Matters: Diffusion Tensor Imaging Tractography in Left and Right Temporal Lobe Epilepsy AJNR Am. J. Neuroradiol., October 1, 2009; 30(9): 1740 - 1747. [Abstract] [Full Text] [PDF]

				Y. Nakata, A.J. Barkovich, M. Wahl, Z. Strominger, R.J. Jeremy, M. Wakahiro, P. Mukherjee, and E.H. Sherr Diffusion Abnormalities and Reduced Volume of the Ventral Cingulum Bundle in Agenesis of the Corpus Callosum: A 3T Imaging Study AJNR Am. J. Neuroradiol., June 1, 2009; 30(6): 1142 - 1148. [Abstract] [Full Text] [PDF]

				M. Wahl, Z. Strominger, R.J. Jeremy, A.J. Barkovich, M. Wakahiro, E.H. Sherr, and P. Mukherjee Variability of Homotopic and Heterotopic Callosal Connectivity in Partial Agenesis of the Corpus Callosum: A 3T Diffusion Tensor Imaging and Q-Ball Tractography Study AJNR Am. J. Neuroradiol., February 1, 2009; 30(2): 282 - 289. [Abstract] [Full Text] [PDF]