Lia Talozzi1, Claudia Testa1, Stefania Evangelisti1, Lorenzo Cirignotta1, Claudio Bianchini1, Stefano Ratti2, Paola Fantazzini3, Caterina Tonon4, David Neil Manners1, Raffaele Lodi5. 1. Department of Biomedical and NeuroMotor Sciences, Functional MR Unit, University of Bologna, Bologna, Italia. 2. Department of Biomedical and NeuroMotor Sciences, Cellular Signalling Laboratory, University of Bologna, Bologna, Italia. 3. Department of Physics and Astronomy, University of Bologna, Bologna, Italy, and Centro Enrico Fermi, Roma, Italia. 4. Department of Biomedical and NeuroMotor Sciences, Functional MR Unit, University of Bologna, Bologna, Italia; IRCCS Istituto delle Scienze Neurologiche di Bologna, Diagnostica Funzionale Neuroradiologica, Bologna, Italia. Electronic address: caterina.tonon@unibo.it. 5. Department of Biomedical and NeuroMotor Sciences, Functional MR Unit, University of Bologna, Bologna, Italia; IRCCS Istituto delle Scienze Neurologiche di Bologna, Diagnostica Funzionale Neuroradiologica, Bologna, Italia.
Abstract
PURPOSE: We propose a new along-tract algorithm to compare different tractography algorithms in tract curvature mapping and along-tract analysis of the arcuate fasciculus (AF). In particular, we quantified along-tract diffusion parameters and AF spatial distribution evaluating hemispheric asymmetries in a group of healthy subjects. METHODS: The AF was bilaterally reconstructed in a group of 29 healthy subjects using the probabilistic ball-and-sticks model, and both deterministic and probabilistic constrained spherical deconvolution. We chose cortical ROIs as tractography targets and the developed along-tract algorithm used the Laplacian operator to parameterize the volume of the tract, allowing along-tract analysis and tract curvature mapping independent of the tractography algorithm used. RESULTS: The Laplacian parameterization successfully described the tract geometry underlying hemispheric asymmetries in the AF curvature. Using the probabilistic tractography methods, we found more tracts branching towards cortical terminations in the left hemisphere. This influenced the left AF curvature and its diffusion parameters, which were significantly different with respect to the right. In particular, we detected projections towards the middle temporal and inferior frontal gyri bilaterally, and towards the superior temporal and precentral gyri in the left hemisphere, with a significantly increased volume and connectivity. CONCLUSIONS: The approach we propose is useful to evaluate brain asymmetries, assessing the volume, the diffusion properties and the quantitative spatial localization of the AF.
PURPOSE: We propose a new along-tract algorithm to compare different tractography algorithms in tract curvature mapping and along-tract analysis of the arcuate fasciculus (AF). In particular, we quantified along-tract diffusion parameters and AF spatial distribution evaluating hemispheric asymmetries in a group of healthy subjects. METHODS: The AF was bilaterally reconstructed in a group of 29 healthy subjects using the probabilistic ball-and-sticks model, and both deterministic and probabilistic constrained spherical deconvolution. We chose cortical ROIs as tractography targets and the developed along-tract algorithm used the Laplacian operator to parameterize the volume of the tract, allowing along-tract analysis and tract curvature mapping independent of the tractography algorithm used. RESULTS: The Laplacian parameterization successfully described the tract geometry underlying hemispheric asymmetries in the AF curvature. Using the probabilistic tractography methods, we found more tracts branching towards cortical terminations in the left hemisphere. This influenced the left AF curvature and its diffusion parameters, which were significantly different with respect to the right. In particular, we detected projections towards the middle temporal and inferior frontal gyri bilaterally, and towards the superior temporal and precentral gyri in the left hemisphere, with a significantly increased volume and connectivity. CONCLUSIONS: The approach we propose is useful to evaluate brain asymmetries, assessing the volume, the diffusion properties and the quantitative spatial localization of the AF.
Authors: Valentina Pieri; Francesco Sanvito; Marco Riva; Alessandro Petrini; Paola M V Rancoita; Sara Cirillo; Antonella Iadanza; Lorenzo Bello; Antonella Castellano; Andrea Falini Journal: Hum Brain Mapp Date: 2020-12-04 Impact factor: 5.038
Authors: Tim Wende; Johannes Kasper; Florian Wilhelmy; Eric Dietel; Gordian Hamerla; Cordula Scherlach; Jürgen Meixensberger; Michael Karl Fehrenbach Journal: Brain Sci Date: 2021-05-16