title: In vivo assessment of white matter damage in neuromyelitis optica: a diffusion tensor and diffusion kurtosis MR imaging study.
abstract: OBJECTIVE
  In patients with neuromyelitis optica (NMO), damage to extensive regions of normal-appearing WM has been observed. To investigate the possibility that microstructural alterations are present in these WM tracts, DTI and diffusion kurtosis imaging (DKI) techniques were applied and compared.
  
  
  METHODS
  Thirteen patients with NMO and 13 demographically and gender-matched controls underwent MRI using a 3T MR scanner, with DTI/DKI sequence acquired jointly fitted. Parametric fractional anisotropy maps were derived from diffusion tensor (FADTI) values using b-values of 0s/mm(2) and 1000s/mm(2). Parametric fractional anisotropy maps derived from diffusion kurtosis tensor (FADKI) values were also acquired using b-values of 0, 1000, and 2000s/mm(2). Mean FADTI and FADKI values were also calculated. A ROI analysis of the genu and splenium of the corpus callosum (CC), cerebral peduncle (CP), and optic radiation (OR) was also performed. Student's t-test and corrections for multiple comparisons were used to evaluate the data obtained.
  
  
  RESULTS
  A significant decrease in the FADTI values obtained for NMO patients versus controls was observed for the splenium of the CC and the left OR (p<0.05). However, just a positive trend was observed for the FADKI values associated with the same WM tracts.
  
  
  CONCLUSIONS
  To our knowledge, this is the first study to analyze WM tracts of NMO patients using DTI and DKI. These data indicate that DKI could have limitations in evaluating the WM integrity in NMO patients. Furthermore, the results obtained are consistent with the hypothesis that diffuse brain involvement characterizes NMO.
authors.affiliation: MRI Department of Clínica de Diagnóstico por Imagem (CDPI), Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: detekimura@hotmail.com.
authors.forename: Margareth Cristina Goncalves
authors.initials: MC
authors.lastname: Kimura
authors.affiliation: Radiology Department of Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Rio de Janeiro, Brazil; Clínica de Diagnóstico por Imagem (CDPI), Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: thomas.doring@gmail.com.
authors.forename: Thomas Martin
authors.initials: TM
authors.lastname: Doring
authors.affiliation: MRI Department of Clínica de Diagnóstico por Imagem (CDPI), Rio de Janeiro, Rio de Janeiro, Brazil; Radiology Department of Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: frueda81@hotmail.com.
authors.forename: Fernanda Cristina
authors.initials: FC
authors.lastname: Rueda
authors.affiliation: Radiology Department of Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Rio de Janeiro, Brazil; Clínica de Diagnóstico por Imagem (CDPI), Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: gustavotukamoto@gmail.com.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Tukamoto
authors.affiliation: MRI Department of Clínica de Diagnóstico por Imagem (CDPI), Rio de Janeiro, Rio de Janeiro, Brazil; Radiology Department of Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: egasparetto@gmail.com.
authors.forename: Emerson Leandro
authors.initials: EL
authors.lastname: Gasparetto
mesh_terms: D000293:Adolescent; D000328:Adult; D016880:Anisotropy; D065850:Cerebral Peduncle / Q000473:pathology; D003337:Corpus Callosum / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D056784:Leukoencephalopathies / Q000175:diagnosis* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009471:Neuromyelitis Optica / Q000150:complications*; D065866:Optic Tract / Q000473:pathology; D055815:Young Adult
keywords: Diffusion kurtosis; Diffusion tensor imaging; Fractional anisotropy; Magnetic resonance; Neuromyelitis optica; Non-Gaussian behavior