title: Magnetic resonance diffusion tensor imaging (MRDTI) and tractography in children with septo-optic dysplasia.
abstract: BACKGROUND
  Septo-optic dysplasia (SOD) refers to a heterogeneous group of midline brain developmental anomalies, with optic nerve hypoplasia (ONH) being one of the morphologic correlates of the condition. Traditionally, ONH has been diagnosed on fundoscopic exam. Conventional MRI is used in cases of suspected ONH to identify associated brain abnormalities and to compare findings to the fundoscopic exam. Advances in magnetic resonance diffusion tensor imaging (MRDTI) permit in vivo, noninvasive, quantitative characterization of the entire visual pathway at 3.0 T.
  
  
  OBJECTIVE
  To investigate the feasibility of MRDTI at 3.0 T in children with SOD to evaluate the entire visual pathway.
  
  
  METHODS
  MRDTI at 3T was performed in two children with SOD and seven age-matched controls. Manual region-of-interest analysis was used to evaluate the tensor metrics of the optic nerves. Deterministic tractography was used to evaluate the tensor metrics of the optic radiations.
  
  
  RESULTS
  The SOD patients demonstrated a significant decrease in anisotropy and increase in mean diffusivity of the optic nerves and radiations compared to the control subjects.
  
  
  CONCLUSIONS
  This study demonstrates the feasibility of MRDTI to evaluate the entire visual pathway in children, and it demonstrates pre- and post-chiasmatic diffusion tensor abnormalities in SOD patients.
authors.affiliation: University of Vermont College of Medicine-Fletcher Allen Health Care, 111 Colchester Ave., Burlington, VT 05401, USA. msalmela@uvm.edu
authors.forename: Michael B
authors.initials: MB
authors.lastname: Salmela
authors.forename: Keith A
authors.initials: KA
authors.lastname: Cauley
authors.forename: Joshua P
authors.initials: JP
authors.lastname: Nickerson
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Koski
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Filippi
mesh_terms: D001921:Brain / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025962:Septo-Optic Dysplasia / Q000473:pathology*