title: Novel diffusion tensor imaging findings in Krabbe disease.
abstract: BACKGROUND
  Krabbe disease is a lysosomal disorder that primarily affects myelin. Diffusion tensor imaging (DTI) provides quantitative information about the white matter organization and integrity. Radial diffusivity (RD) reflects myelin injury selectively.
  
  
  OBJECTIVE
  To report on quantitative DTI findings (including axial diffusivity (AD) and RD, not previously reported) in two children with Krabbe disease compared to controls.
  
  
  METHODS
  A quantitative region of interest (ROI) based DTI analysis was performed for the patients and age- and gender-matched controls. Fractional anisotropy (FA), mean diffusivity, AD and RD values as well as variation ratios between the patients' and controls' values were calculated for nine brain regions.
  
  
  RESULTS
  Two boys with Krabbe disease were included in this study. DTI data were acquired at the ages of 6.25 years and 6.5 months. For all regions, FA ratios were negative, while RD and MD ratios positive. The most elevated variation ratios were found for RD. Variation ratios were greater in the centrum semiovale, corpus callosum, and middle cerebellar peduncles than in other anatomical regions, especially in the older patient in comparison with the younger patient. The AD ratios, however, were much lower and close to zero.
  
  
  CONCLUSIONS
  DTI allows a quantitative evaluation of white matter damage in Krabbe disease. RD seems to be the most sensitive DTI parameter in agreement with the histopathological findings in Krabbe disease, a primary myelin disorder. This may be important in the early detection of the onset of demyelination.
authors.affiliation: Section of Pediatric Neuroradiology, Division of Pediatric Radiology, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins School of Medicine, Baltimore, MD, USA. Electronic address: aporett1@jhmi.edu.
authors.forename: Andrea
authors.initials: A
authors.lastname: Poretti
authors.affiliation: Section of Pediatric Neuroradiology, Division of Pediatric Radiology, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins School of Medicine, Baltimore, MD, USA.
authors.forename: Avner
authors.initials: A
authors.lastname: Meoded
authors.affiliation: Department of Radiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Martin
authors.initials: M
authors.lastname: Bunge
authors.affiliation: Kennedy Krieger Institute, Baltimore, MD, USA; Department of Neurology, The Johns Hopkins School of Medicine, Baltimore, MD, USA.
authors.forename: Ali
authors.initials: A
authors.lastname: Fatemi
authors.affiliation: Department of Diagnostic Imaging, Health Sciences Centre, Winnipeg, Manitoba, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Barrette
authors.affiliation: Section of Pediatric Neuroradiology, Division of Pediatric Radiology, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins School of Medicine, Baltimore, MD, USA.
authors.forename: Thierry A G M
authors.initials: TA
authors.lastname: Huisman
authors.affiliation: Section of Pediatric Neurology, Department of Pediatrics and Child Health, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Salman
mesh_terms: D017668:Age of Onset; D016880:Anisotropy; D001921:Brain / Q000473:pathology*; D002648:Child; D056324:Diffusion Tensor Imaging; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007223:Infant; D007965:Leukodystrophy, Globoid Cell / Q000473:pathology*; D008297:Male
keywords: Diffusion tensor imaging; Krabbe disease; Magnetic resonance imaging; Radial diffusivity