title: An efficient calculation method for pharmacokinetic parameters in brain permeability study using dynamic contrast-enhanced MRI.
abstract: OBJECTIVE
  To develop an efficient method for calculating pharmacokinetic (PK) parameters in brain DCE-MRI permeability studies.
  
  
  METHODS
  A linear least-squares fitting algorithm based on a derivative expression of the two-compartment PK model was proposed to analytically solve for the PK parameters. Noise in the expression was minimized through low-pass filtering. Simulation studies were conducted in which the proposed method was compared with two existing methods in terms of accuracy and efficiency. Five in vivo brain studies were demonstrated for potential clinical application.
  
  
  RESULTS
  In the simulation studies using chosen parameter values, the calculated percent difference of K(trans) by the proposed method was <5.0% with a temporal resolution (Δt) < 5 s, and the accuracies of all parameter results were better or comparable to existing methods. When analyzed within certain parameter intensity ranges, the proposed method was more accurate than the existing methods and improved the efficiency by a factor of up to 458 for a Δt = 1 s and up to 38 for a Δt = 5 s. In the in vivo study, the calculated parameters using the proposed method were comparable to those using the existing methods with improved efficiencies.
  
  
  CONCLUSIONS
  An efficient method was developed for the accurate and efficient calculation of parameters in brain DCE-MRI permeability studies.
authors.affiliation: Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, USA.
authors.forename: Chunhao
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, USA.
authors.forename: Fang-Fang
authors.initials: FF
authors.lastname: Yin
authors.affiliation: Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, USA.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Chang
mesh_terms: D000465:Algorithms; D001921:Brain / Q000378:metabolism*; D003198:Computer Simulation; D003287:Contrast Media / Q000493:pharmacokinetics*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*
chemical_list: D003287:Contrast Media
keywords: DCE-MRI; computation efficiency; computer simulation; permeability parameter calculation