title: Revealing signal from noisy (19) F MR images by chemical shift artifact correction.
abstract: OBJECTIVE
  The correction of chemical shift artifacts in MR images of fluorinated molecules with a multi-resonance spectrum is investigated. The goal is to find a deconvolution method which is capable of correcting the artifact, thereby enhancing signal-to-noise ratio (SNR) and revealing signal that vanishes in the noise in the original image.
  
  
  METHODS
  Simulations for inspecting the influence of MRI acquisition parameters on the possibility to correct the artifact are performed. Artifact correction is studied on the spectrum of a perfluorocarbon compound by means of deconvolution of complex images with a measured or an optimized point spread function and by using lasso regularization.
  
  
  RESULTS
  Distinct parameter settings for image acquisition are identified that should be avoided for successful deconvolution. With in vitro and in vivo images it is shown that the SNR of the corrected image can be increased significantly by 20-50% by a regularized deconvolution of the artifact image and (19) F signal can be revealed from noise.
  
  
  CONCLUSIONS
  By deconvolution, SNR can be enhanced as compared to an image which only exploits the strongest peak of the spectrum. Thus, the limit of detection of the (19) F signal can be lowered by exciting all resonances and by means of correcting the chemical shift artifact.
authors.affiliation: Department of Radiology, Medical Physics, University Medical Center Freiburg, Germany.
authors.forename: Mirko
authors.initials: M
authors.lastname: Meissner
authors.affiliation: Department of Radiology, Medical Physics, University Medical Center Freiburg, Germany.
authors.forename: Marco
authors.initials: M
authors.lastname: Reisert
authors.affiliation: Department of Radiology, Medical Physics, University Medical Center Freiburg, Germany.
authors.forename: Thimo
authors.initials: T
authors.lastname: Hugger
authors.affiliation: Department of Radiology, Medical Physics, University Medical Center Freiburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hennig
authors.affiliation: Department of Radiology, Medical Physics, University Medical Center Freiburg, Germany.
authors.forename: Dominik
authors.initials: D
authors.lastname: von Elverfeldt
authors.affiliation: Department of Radiology, Medical Physics, University Medical Center Freiburg, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Leupold
mesh_terms: D016477:Artifacts; D003198:Computer Simulation; D003287:Contrast Media / Q000737:chemistry*; D005466:Fluorocarbons / Q000737:chemistry*; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D059629:Signal-To-Noise Ratio
chemical_list: D003287:Contrast Media; D005466:Fluorocarbons
keywords: MRI; chemical shift artifact; deconvolution; fluorine imaging; regularization