title: Diffusion tensor imaging and tractography of distal peripheral nerves at 3 T.
abstract: OBJECTIVE
  We studied whether distal peripheral nerves could be imaged using quantitative diffusion tensor imaging (DTI) with a 3-T MRI scanner, and visualized using tractography.
  
  
  METHODS
  Altogether 6 healthy subjects were studied. The diffusion was quantified with apparent diffusion coefficient (ADC) and fractional anisotropy (FA) maps, and the direction of main diffusivity was visualized with color-coded orientation maps and tractography.
  
  
  RESULTS
  We present the first DTI and tractography results of human distal peripheral nerves. The courses of median, ulnar, and radial nerves in the upper limb and of tibial and peroneal nerves in the lower limb were first analyzed quantifying ADC and FA, and then visualized in 3D with tractography. Tractography illustrated nicely the 3D courses of both upper and lower limb nerves which were reliably distinguished from the surrounding muscle tissue and ligaments.
  
  
  CONCLUSIONS
  Quantitative DTI and tractography can be used to image and visualize distal peripheral nerves.
  
  
  CONCLUSIONS
  DTI is a quantitative method that could provide useful information for the diagnosis and follow-up of nerve lesions, entrapments, and regeneration. Peripheral nerves as well-delineated structures also containing abundant branching into bundles of different diameters, could be used as 'living phantoms' for testing and validating different tractography methods.
authors.affiliation: Brain Research Unit, Low Temperature Laboratory, Helsinki University of Technology, P.O. Box 2200, 02015 Espoo, HUT, Finland. jaana@neuro.hut.fi
authors.forename: Jaana
authors.initials: J
authors.lastname: Hiltunen
authors.forename: Taru
authors.initials: T
authors.lastname: Suortti
authors.forename: Sakari
authors.initials: S
authors.lastname: Arvela
authors.forename: Mika
authors.initials: M
authors.lastname: Seppä
authors.forename: Raimo
authors.initials: R
authors.lastname: Joensuu
authors.forename: Riitta
authors.initials: R
authors.lastname: Hari
mesh_terms: D000328:Adult; D000465:Algorithms; D016880:Anisotropy; D001921:Brain / Q000033:anatomy & histology; D003627:Data Interpretation, Statistical; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008022:Ligaments / Q000033:anatomy & histology; D008279:Magnetic Resonance Imaging; D008297:Male; D008953:Models, Anatomic; D018482:Muscle, Skeletal / Q000033:anatomy & histology; D009434:Neural Pathways / Q000033:anatomy & histology*; D010525:Peripheral Nerves / Q000033:anatomy & histology*; D012984:Software; D014794:Visual Fields / Q000502:physiology