title: Tractography at 3T MRI of Corpus Callosum Tracts Crossing White Matter Hyperintensities.
abstract: The impact of white matter hyperintensities on the diffusion characteristics of crossing tracts is unclear. This study used quantitative tractography at 3T MR imaging to compare, in the same individuals, the diffusion characteristics of corpus callosum tracts that crossed white matter hyperintensities with the diffusion characteristics of corpus callosum tracts that did not pass through white matter hyperintensities.
  
  
  
  Brain T2 fluid-attenuated inversion recovery-weighted and diffusion tensor 3T MR imaging scans were acquired in 24 individuals with white matter hyperintensities. Tractography data were generated by the Fiber Assignment by Continuous Tracking method. White matter hyperintensities and corpus callosum tracts were manually segmented. In the corpus callosum, the fractional anisotropy, radial diffusivity, and mean diffusivity of tracts crossing white matter hyperintensities were compared with the fractional anisotropy, radial diffusivity, and mean diffusivity of tracts that did not cross white matter hyperintensities. The cingulum, long association fibers, corticospinal/bulbar tracts, and thalamic projection fibers were included for comparison.
  
  
  
  Within the corpus callosum, tracts that crossed white matter hyperintensities had decreased fractional anisotropy compared with tracts that did not pass through white matter hyperintensities (P = .002). Within the cingulum, tracts that crossed white matter hyperintensities had increased radial diffusivity compared with tracts that did not pass through white matter hyperintensities (P = .001).
  
  
  
  In the corpus callosum and cingulum, tracts had worse diffusion characteristics when they crossed white matter hyperintensities. These results support a role for white matter hyperintensities in the disruption of crossing tracts.
authors.affiliation: From the Departments of Medical Imaging (W.R.) Memory Clinics (W.R., A.G.), Division of Geriatric Medicine, Department of Medicine wreginold@qmed.ca.
authors.forename: W
authors.identifier: 0000-0001-5325-7561
authors.initials: W
authors.lastname: Reginold
authors.affiliation: Centre for Neuroscience Studies (J.I., A.G., A.C.L.), Queen's University, Kingston, Ontario, Canada.
authors.forename: J
authors.identifier: 0000-0002-8578-2771
authors.initials: J
authors.lastname: Itorralba
authors.affiliation: Centre for Neuroscience Studies (J.I., A.G., A.C.L.), Queen's University, Kingston, Ontario, Canada.
authors.forename: A C
authors.identifier: 0000-0001-9530-4629
authors.initials: AC
authors.lastname: Luedke
authors.affiliation: Facultad de Medicina, (J.F.-R.), Universidad Nacional Autonoma de Mexico, Coyoacán, Mexico.
authors.forename: J
authors.identifier: 0000-0002-4038-0904
authors.initials: J
authors.lastname: Fernandez-Ruiz
authors.affiliation: Life Sciences (J.R.), University of Toronto, Toronto, Ontario, Canada.
authors.forename: J
authors.identifier: 0000-0002-1035-3235
authors.initials: J
authors.lastname: Reginold
authors.affiliation: Department of Diagnostic Radiology (O.I.), Kingston General Hospital, Queen's University, Kingston, Ontario, Canada.
authors.forename: O
authors.identifier: 0000-0002-3222-9374
authors.initials: O
authors.lastname: Islam
authors.affiliation: Memory Clinics (W.R., A.G.), Division of Geriatric Medicine, Department of Medicine Centre for Neuroscience Studies (J.I., A.G., A.C.L.), Queen's University, Kingston, Ontario, Canada.
authors.forename: A
authors.identifier: 0000-0002-5907-8924
authors.initials: A
authors.lastname: Garcia
mesh_terms: D016880:Anisotropy; D003337:Corpus Callosum / Q000000981:diagnostic imaging*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D011712:Pyramidal Tracts / Q000000981:diagnostic imaging; D066127:White Matter / Q000000981:diagnostic imaging*