Poster C124, Sunday, March 25, 1:00-3:00 pm, Exhibit Hall C
Improved diffusion Magnetic Resonance Imaging reconstruction of the Arcuate Fasciculus
Elise B. Barbeau1,2,3, Kaija Sander1,2,3, Shanna Kousaie1,3, Thomas Liontis3, Denise Klein1,2,3, Michael Petrides1,2,4; 1Cognitive Neuroscience Unit, Montreal Neurological Institute, McGill University, 2Department of Neurology and Neurosurgery, McGill University, 3Center for Research on Brain, Language and Music (CRBLM), Montreal, 4Department of Psychology, McGill University
The Arcuate Fasciculus (AF) is a white matter tract connecting the posterior temporal region involved in the comprehension of language with the inferior frontal gyrus (Broca’s region). Several studies have used diffusion Magnetic Resonance Imaging (MRI) data to reconstruct the AF using a method proposed by Catani et al (2005). In the present study, we aimed to improve the reconstruction of the AF which must be distinguished from the Superior Longitudinal Fasciculus (SLF) originating from the inferior parietal lobule and coursing parallel to the AF and, also, from temporo-occipital fibers and fibers originating in the anterior temporal lobe. This reconstruction was carried out in 50 right-handed healthy volunteers (mean age 23.9 yrs, range 18-34) who had been scanned with MRI (diffusion and anatomical) and who performed language behavioral tests. The diffusion MRI images were preprocessed using FSL and the AF was reconstructed with Diffusion Toolkit and Trackvis using Regions of Interests (ROIs) drawn on the diffusion and coregistered anatomical scans. The basic ROIs were comparable to those in the Catani AF long segment reconstruction, but we used exclusion ROIs to isolate fibers from the posterior temporal lobe from those originating in more anterior temporal areas, the temporo-occipital fibers, and those ending in the inferior parietal lobule and which belong to the SLF. The AF was successfully reconstructed in all participants by two independent raters. In line with Thiebaut de Schotten et al (2014), there was a correlation between the structural properties of the AF and speed of reading paragraphs aloud.
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