title: Interpolation of orientation distribution functions in diffusion weighted imaging using multi-tensor model.
abstract: BACKGROUND
  Diffusion weighted imaging (DWI) is a non-invasive method for investigating the brain white matter structure and can be used to evaluate fiber bundles. However, due to practical constraints, DWI data acquired in clinics are low resolution.
  
  
  METHODS
  This paper proposes a method for interpolation of orientation distribution functions (ODFs). To this end, fuzzy clustering is applied to segment ODFs based on the principal diffusion directions (PDDs). Next, a cluster is modeled by a tensor so that an ODF is represented by a mixture of tensors. For interpolation, each tensor is rotated separately.
  
  
  RESULTS
  The method is applied on the synthetic and real DWI data of control and epileptic subjects. Both experiments illustrate capability of the method in increasing spatial resolution of the data in the ODF field properly. The real dataset show that the method is capable of reliable identification of differences between temporal lobe epilepsy (TLE) patients and normal subjects.
  
  
  METHODS
  The method is compared to existing methods. Comparison studies show that the proposed method generates smaller angular errors relative to the existing methods. Another advantage of the method is that it does not require an iterative algorithm to find the tensors.
  
  
  CONCLUSIONS
  The proposed method is appropriate for increasing resolution in the ODF field and can be applied to clinical data to improve evaluation of white matter fibers in the brain.
authors.affiliation: Department of Electrical Engineering Biomedical Signal and Image Processing Laboratory (BiSIPL), Sharif University of Technology, Tehran, Iran. Electronic address: afzali@ee.sharif.edu.
authors.forename: Maryam
authors.initials: M
authors.lastname: Afzali
authors.affiliation: Department of Electrical Engineering Biomedical Signal and Image Processing Laboratory (BiSIPL), Sharif University of Technology, Tehran, Iran. Electronic address: fatemizadeh@sharif.edu.
authors.forename: Emad
authors.initials: E
authors.lastname: Fatemizadeh
authors.affiliation: Control and Intelligent Processing Center of Excellence (CIPCE), School of Electrical and Computer Engineering, University of Tehran, Tehran, Iran; School of Cognitive Sciences (SCS), Institute for Research in Fundamental Sciences (IPM), Tehran, Iran; Image Analysis Laboratory, Department of Radiology, Henry Ford Health System, Detroit, MI, USA. Electronic address: hamids@rad.hfh.edu.
authors.forename: Hamid
authors.initials: H
authors.lastname: Soltanian-Zadeh
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D001921:Brain / Q000502:physiology*; D038524:Diffusion Magnetic Resonance Imaging; D004833:Epilepsy, Temporal Lobe / Q000473:pathology / Q000503:physiopathology; D005260:Female; D017143:Fuzzy Logic; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D009949:Orientation; D010363:Pattern Recognition, Automated; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: Diffusion weighted imaging (DWI); Interpolation; Multi-tensor; Orientation distribution function (ODF); Temporal lobe epilepsy (TLE)