title: Magnetic resonance brain perfusion imaging with voxel-specific arterial input functions.
abstract: OBJECTIVE
  To propose an automatic method for estimating voxel-specific arterial input functions (AIFs) in dynamic contrast brain perfusion imaging.
  
  
  METHODS
  Voxel-specific AIFs were estimated blindly using the theory of homomorphic transformations and complex cepstrum analysis. Wiener filtering was used in the subsequent deconvolution. The method was verified using simulated data and evaluated in 10 healthy adults.
  
  
  RESULTS
  Computer simulations accurately estimated differently shaped, normalized AIFs. Simple Wiener filtering resulted in underestimation of flow values. Preliminary in vivo results showed comparable cerebral flow value ratios between gray matter (GM) and white matter (WM) when using blindly estimated voxel-specific AIFs or a single manually selected AIF. Significant differences (P < or = 0.0125) in mean transit time (MTT) and time-to-peak (TTP) in GM compared to WM was seen with the new method.
  
  
  CONCLUSIONS
  Initial results suggest that the proposed method can replace the tedious and difficult task of manually selecting an AIF, while simultaneously providing better differentiation between time-dependent hemodynamic parameters.
authors.affiliation: Department of Biomedicine, University of Bergen, Haukeland University Hospital, N-5021 Bergen, Norway. renate@fmri.no
authors.forename: Renate
authors.initials: R
authors.lastname: Grüner
authors.forename: Bård T
authors.initials: BT
authors.lastname: Bjørnarå
authors.forename: Gunnar
authors.initials: G
authors.lastname: Moen
authors.forename: Torfinn
authors.initials: T
authors.lastname: Taxt
mesh_terms: D000328:Adult; D000465:Algorithms; D002560:Cerebrovascular Circulation; D003198:Computer Simulation; D003287:Contrast Media; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009010:Monte Carlo Method; D009413:Nerve Fibers, Myelinated; D036421:Nerve Fibers, Unmyelinated; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media