title: Fiber tractography based on diffusion tensor imaging compared with high-angular-resolution diffusion imaging with compressed sensing:  initial experience.
abstract: BACKGROUND
  The most frequently used method for fiber tractography based on diffusion tensor imaging (DTI) is associated with restrictions in the resolution of crossing or kissing fibers and in the vicinity of tumor or edema. Tractography based on high-angular-resolution diffusion imaging (HARDI) is capable of overcoming this restriction. With compressed sensing (CS) techniques, HARDI acquisitions with a smaller number of directional measurements can be used, thus enabling the use of HARDI-based fiber tractography in clinical practice.
  
  
  OBJECTIVE
  To investigate whether HARDI+CS-based fiber tractography improves the display of neuroanatomically complex pathways and in areas of disturbed diffusion properties.
  
  
  METHODS
  Six patients with gliomas in the vicinity of language-related areas underwent 3-T magnetic resonance imaging including a diffusion-weighted data set with 30 gradient directions. Additionally, functional magnetic resonance imaging for cortical language sites was obtained. Fiber tractography was performed with deterministic streamline algorithms based on DTI using 3 different software platforms. Additionally, tractography based on reconstructed diffusion signals using HARDI+CS was performed.
  
  
  RESULTS
  HARDI+CS-based tractography displayed more compact fiber bundles compared with the DTI-based results in all cases. In 3 cases, neuroanatomically plausible fiber bundles were displayed in the vicinity of tumor and peritumoral edema, which could not be traced on the basis of DTI. The curvature around the sylvian fissure was displayed properly in 6 cases and in only 2 cases with DTI-based tractography.
  
  
  CONCLUSIONS
  HARDI+CS seems to be a promising approach for fiber tractography in clinical practice for neuroanatomically complex fiber pathways and in areas of disturbed diffusion, overcoming the problem of long acquisition times.
authors.affiliation: Department of Neurosurgery, University of Marburg, Marburg, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Kuhnt
authors.forename: Miriam H A
authors.initials: MH
authors.lastname: Bauer
authors.forename: Jan
authors.initials: J
authors.lastname: Egger
authors.forename: Mirco
authors.initials: M
authors.lastname: Richter
authors.forename: Tina
authors.initials: T
authors.lastname: Kapur
authors.forename: Jens
authors.initials: J
authors.lastname: Sommer
authors.forename: Dorit
authors.initials: D
authors.lastname: Merhof
authors.forename: Christopher
authors.initials: C
authors.lastname: Nimsky
mesh_terms: D000328:Adult; D000368:Aged; D001929:Brain Edema / Q000473:pathology; D001932:Brain Neoplasms / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D005910:Glioma / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D009434:Neural Pathways / Q000473:pathology; D009445:Neuroanatomy / Q000379:methods; D011446:Prospective Studies