title: Quantitative high-field diffusion tensor imaging of cerebral white matter in asymptomatic high-grade internal carotid artery stenosis.
abstract: BACKGROUND
  Recently, several studies using diffusion-sensitized MRI reported changes in patients with high-grade internal carotid artery stenosis (ICAS) suggestive of subtle brain tissue damage. We used diffusion tensor imaging (DTI) to investigate the microstructural cerebral white matter integrity in asymptomatic patients with high-grade ICAS.
  
  
  METHODS
  In 15 asymptomatic patients with unilateral high grade (>70%) ICAS, we used 3T MRI including DTI. We used a region-of-interest approach comparing quantitative DTI metrics between both hemispheres including the so-called border zones. MR images were also assessed for periventricular white matter lesions (PWML) as well as collaterals via the circle of Willis.
  
  
  RESULTS
  There was no significant intraindividual difference of fractional anisotropy or mean diffusivity values between the hemispheres for any region. PWML was graded 0° in 6 patients, I° in 9 and II° in 2.
  
  
  CONCLUSIONS
  In clinically asymptomatic patients with high-grade unilateral ICAS, there was no difference between the DTI parameters of the affected and the unaffected hemisphere. These findings contrast with other studies in asymptomatic high-grade ICAS, which is likely due to patient selection. These findings argue against concomitant chronic tissue integrity changes and implicate the benignity of asymptomatic carotid artery disease in individual patients.
authors.affiliation: Department of Neuroradiology, University of Heidelberg, Heidelberg, Germany. christian.herweh@med.uni-heidelberg.de
authors.forename: C
authors.initials: C
authors.lastname: Herweh
authors.forename: N
authors.initials: N
authors.lastname: Attigah
authors.forename: S
authors.initials: S
authors.lastname: Nagel
authors.forename: S
authors.initials: S
authors.lastname: Demirel
authors.forename: P A
authors.initials: PA
authors.lastname: Ringleb
authors.forename: D
authors.initials: D
authors.lastname: Boeckler
authors.forename: M
authors.initials: M
authors.lastname: Bendszus
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016880:Anisotropy; D016893:Carotid Stenosis / Q000175:diagnosis*; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D005260:Female; D007839:Functional Laterality; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D014463:Ultrasonography