title: Tract-based spatial statistical analysis of diffusion tensor imaging in pediatric patients with mitochondrial disease: widespread reduction in fractional anisotropy of white matter tracts.
abstract: OBJECTIVE
  Often diagnosed at birth or in early childhood, mitochondrial disease presents with a variety of clinical symptoms, particularly in organs and tissues that require high energetic demand such as brain, heart, liver, and skeletal muscles. In a group of pediatric patients identified as having complex I or I/III deficits on muscle biopsy but with white matter tissue appearing qualitatively normal for age, we hypothesized that quantitative DTI analyses might unmask disturbance in microstructural integrity.
  
  
  METHODS
  In a retrospective study, DTI and structural MR brain imaging data from 10 pediatric patients with confirmed mitochondrial disease and 10 clinical control subjects were matched for age, sex, scanning parameters, and date of examination. Paired TBSS was performed to evaluate differences in FA, MD, and the separate diffusion direction terms (λr and λa).
  
  
  RESULTS
  In patients with mitochondrial disease, significant widespread reductions in FA values were shown in white matter tracts. Mean diffusivity values were significantly increased in patients, having a sparser distribution of affected regions compared with FA. Separate diffusion maps showed significant increase in λr and no significant changes in λa.
  
  
  CONCLUSIONS
  Despite qualitatively normal-appearing white matter tissues, patients with complex I or I/III deficiency have widespread microstructural changes measurable with quantitative DTI.
authors.affiliation: Seattle Children's Hospital, Department of Radiology, 4800 Sandpoint Way, M/S R-5417, Seattle, Washington 98105, USA. ishakg@u.washington.edu
authors.forename: G E
authors.initials: GE
authors.lastname: Ishak
authors.forename: A V
authors.initials: AV
authors.lastname: Poliakov
authors.forename: S L
authors.initials: SL
authors.lastname: Poliachik
authors.forename: R P
authors.initials: RP
authors.lastname: Saneto
authors.forename: E J
authors.initials: EJ
authors.lastname: Novotny
authors.forename: S
authors.initials: S
authors.lastname: McDaniel
authors.forename: J G
authors.initials: JG
authors.lastname: Ojemann
authors.forename: D W W
authors.initials: DW
authors.lastname: Shaw
authors.forename: S D
authors.initials: SD
authors.lastname: Friedman
mesh_terms: D000465:Algorithms; D016880:Anisotropy; D001921:Brain / Q000473:pathology*; D002648:Child; D003627:Data Interpretation, Statistical; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D028361:Mitochondrial Diseases / Q000473:pathology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity