title: Diffusion tensor imaging of the cervical spinal cord of patients with Neuromyelitis Optica.
abstract: BACKGROUND
  Previous studies have demonstrated a correlation between Expanded Disability Status Scale (EDSS) and Diffusion Tensor Imaging (DTI) metrics, but the conclusions were based on evaluations of the entire cervical spinal cord.
  
  
  OBJECTIVE
  The purpose of this study was to quantify the FA and MD values in the spinal cord of NMO patients, separating the lesion sites from the preserved sites, which has not been previously preformed. In addition, we attempted to identify a correlation with EDSS.
  
  
  METHODS
  DTI was performed in 11 NMO patients and 11 healthy individuals using a 1.5-T MRI scanner. We measured the FA and MD at ROIs positioned along the cervical spinal cord. The mean values of FA and MD at lesion, preserved and spinal cord sites were compared with those of a control group. We tested the correlations between the mean FA and MD with EDSS.
  
  
  RESULTS
  FA in NMO patients was significantly reduced in lesion sites (0.44 vs. 0.55, p=0.0046), preserved sites (0.46 vs. 0.55, p=0.0015), and all sites (0.45 vs 0.55, p=0.0013) while MD increased only in lesion sites (1.03×10(-3)mm(2)/s vs. 0.90×10(-3)mm(2)/s, p=0.009). The FA demonstrated the best correlation with EDSS (r=-0.7603, p=0.0086), particularly at lesion sites.
  
  
  CONCLUSIONS
  The results reinforce the importance of the FA index and confirm the hypothesis that NMO is a diffuse disease.
authors.affiliation: Departamento de Diagnóstico por Imagem, Universidade Federal de São Paulo-UNIFESP, Brasil. Electronic address: reneleandro3@hotmail.com.
authors.forename: René L M
authors.initials: RL
authors.lastname: Rivero
authors.affiliation: Departamento de Neurologia, Universidade Federal de São Paulo-UNIFESP, Brasil.
authors.forename: Enedina M L
authors.initials: EM
authors.lastname: Oliveira
authors.affiliation: Departamento de Neurologia, Universidade Federal de São Paulo-UNIFESP, Brasil.
authors.forename: Denis B
authors.initials: DB
authors.lastname: Bichuetti
authors.affiliation: Departamento de Neurologia, Universidade Federal de São Paulo-UNIFESP, Brasil.
authors.forename: Alberto A
authors.initials: AA
authors.lastname: Gabbai
authors.affiliation: Departamento de Diagnóstico por Imagem, Universidade Federal de São Paulo-UNIFESP, Brasil.
authors.forename: Roberto G
authors.initials: RG
authors.lastname: Nogueira
authors.affiliation: Departamento de Diagnóstico por Imagem, Universidade Federal de São Paulo-UNIFESP, Brasil.
authors.forename: Nitamar
authors.initials: N
authors.lastname: Abdala
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D066193:Cervical Cord / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009471:Neuromyelitis Optica / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Diffusion tensor imaging; Disability evaluation; Neuromyelitis optica; Spinal cord