title: A simple noise correction scheme for diffusional kurtosis imaging.
abstract: OBJECTIVE
  Diffusional kurtosis imaging (DKI) is sensitive to the effects of signal noise due to strong diffusion weightings and higher order modeling of the diffusion weighted signal. A simple noise correction scheme is proposed to remove the majority of the noise bias in the estimated diffusional kurtosis.
  
  
  METHODS
  Weighted linear least squares (WLLS) fitting together with a voxel-wise, subtraction-based noise correction from multiple, independent acquisitions are employed to reduce noise bias in DKI data. The method is validated in phantom experiments and demonstrated for in vivo human brain for DKI-derived parameter estimates.
  
  
  RESULTS
  As long as the signal-to-noise ratio (SNR) for the most heavily diffusion weighted images is greater than 2.1, errors in phantom diffusional kurtosis estimates are found to be less than 5 percent with noise correction, but as high as 44 percent for uncorrected estimates. In human brain, noise correction is also shown to improve diffusional kurtosis estimates derived from measurements made with low SNR.
  
  
  CONCLUSIONS
  The proposed correction technique removes the majority of noise bias from diffusional kurtosis estimates in noisy phantom data and is applicable to DKI of human brain. Features of the method include computational simplicity and ease of integration into standard WLLS DKI post-processing algorithms.
authors.affiliation: Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA; Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA. Electronic address: glenng@musc.edu.
authors.forename: G Russell
authors.initials: GR
authors.lastname: Glenn
authors.affiliation: Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA; Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Ali
authors.initials: A
authors.lastname: Tabesh
authors.affiliation: Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA; Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Jens H
authors.initials: JH
authors.lastname: Jensen
mesh_terms: D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D003198:Computer Simulation; D003952:Diagnostic Imaging; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016018:Least-Squares Analysis; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D059629:Signal-To-Noise Ratio; D013382:Subtraction Technique
keywords: Brain; Diffusion; Kurtosis; Noise; Phantom; Rician