title: A combined registration and finite element analysis method for fast estimation of intraoperative brain shift; phantom and animal model study.
abstract: BACKGROUND
  Finite element models for estimation of intraoperative brain shift suffer from huge computational cost. In these models, image registration and finite element analysis are two time-consuming processes.
  
  
  METHODS
  The proposed method is an improved version of our previously developed Finite Element Drift (FED) registration algorithm. In this work the registration process is combined with the finite element analysis. In the Combined FED (CFED), the deformation of whole brain mesh is iteratively calculated by geometrical extension of a local load vector which is computed by FED.
  
  
  RESULTS
  While the processing time of the FED-based method including registration and finite element analysis was about 70 s, the computation time of the CFED was about 3.2 s. The computational cost of CFED is almost 50% less than similar state of the art brain shift estimators based on finite element models.
  
  
  CONCLUSIONS
  The proposed combination of registration and structural analysis can make the calculation of brain deformation much faster.
authors.affiliation: Department of Medical Physics & Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Amrollah
authors.initials: A
authors.lastname: Mohammadi
authors.affiliation: Department of Medical Physics & Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.|Research Centre for Biomedical Technology and Robotics (RCBTR), Tehran, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Ahmadian
authors.affiliation: Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Shahram
authors.initials: S
authors.lastname: Rabbani
authors.affiliation: Department of Neurosurgery, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Fattahi
authors.affiliation: Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Shapour
authors.initials: S
authors.lastname: Shirani
mesh_terms: D000465:Algorithms; D000818:Animals; D001921:Brain / Q000473:pathology*; D003198:Computer Simulation; D004285:Dogs; D020342:Finite Element Analysis; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D023421:Models, Animal; D008962:Models, Theoretical; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012984:Software; D013997:Time Factors
keywords: CFED; FED registration; brain shift; finite element analysis