title: Reducing contrast contamination in radial turbo-spin-echo acquisitions by combining a narrow-band KWIC filter with parallel imaging.
abstract: OBJECTIVE
  Cartesian turbo spin-echo (TSE) and radial TSE images are usually reconstructed by assembling data containing different contrast information into a single k-space. This approach results in mixed contrast contributions in the images, which may reduce their diagnostic value. The goal of this work is to improve the image contrast from radial TSE acquisitions by reducing the contribution of signals with undesired contrast information.
  
  
  METHODS
  Radial TSE acquisitions allow the reconstruction of multiple images with different T2 contrasts using the k-space weighted image contrast (KWIC) filter. In this work, the image contrast is improved by reducing the band-width of the KWIC filter. Data for the reconstruction of a single image are selected from within a small temporal range around the desired echo time. The resulting dataset is undersampled and, therefore, an iterative parallel imaging algorithm is applied to remove aliasing artifacts.
  
  
  RESULTS
  Radial TSE images of the human brain reconstructed with the proposed method show an improved contrast when compared with Cartesian TSE images or radial TSE images with conventional KWIC reconstructions.
  
  
  CONCLUSIONS
  The proposed method provides multi-contrast images from radial TSE data with contrasts similar to multi spin-echo images. Contaminations from unwanted contrast weightings are strongly reduced.
authors.affiliation: Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Neumann
authors.forename: Felix A
authors.initials: FA
authors.lastname: Breuer
authors.forename: Michael
authors.initials: M
authors.lastname: Völker
authors.forename: Tobias
authors.initials: T
authors.lastname: Brandt
authors.forename: Mark A
authors.initials: MA
authors.lastname: Griswold
authors.forename: Peter M
authors.initials: PM
authors.lastname: Jakob
authors.forename: Martin
authors.initials: M
authors.lastname: Blaimer
mesh_terms: D000465:Algorithms; D016477:Artifacts; D001921:Brain / Q000033:anatomy & histology*; D017352:Echo-Planar Imaging / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D009038:Motion; D015203:Reproducibility of Results; D018401:Sample Size; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D013113:Spin Labels; D013382:Subtraction Technique
chemical_list: D013113:Spin Labels
keywords: KWIC; RARE; Turbo spin-echo; data sharing; parallel imaging; radial sampling