title: Fast isotropic banding-free bSSFP imaging using 3D dynamically phase-cycled radial bSSFP (3D DYPR-SSFP).
abstract: OBJECTIVE
  Dynamically phase-cycled radial balanced steady-state free precession (DYPR-SSFP) is a method for efficient banding artifact removal in bSSFP imaging. Based on a varying radiofrequency (RF) phase-increment in combination with a radial trajectory, DYPR-SSFP allows obtaining a banding-free image out of a single acquired k-space. The purpose of this work is to present an extension of this technique, enabling fast three-dimensional isotropic banding-free bSSFP imaging.
  
  
  METHODS
  While banding artifact removal with DYPR-SSFP relies on the applied dynamic phase-cycle, this aspect can lead to artifacts, at least when the number of acquired projections lies below a certain limit. However, by using a 3D radial trajectory with quasi-random view ordering for image acquisition, this problem is intrinsically solved, enabling 3D DYPR-SSFP imaging at or even below the Nyquist criterion. The approach is validated for brain and knee imaging at 3 Tesla.
  
  
  RESULTS
  Volumetric, banding-free images were obtained in clinically acceptable scan times with an isotropic resolution up to 0.56mm.
  
  
  CONCLUSIONS
  The combination of DYPR-SSFP with a 3D radial trajectory allows banding-free isotropic volumetric bSSFP imaging with no expense of scan time. Therefore, this is a promising candidate for clinical applications such as imaging of cranial nerves or articular cartilage.
authors.affiliation: Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany. Electronic address: benkert@mr-bavaria.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Benkert
authors.affiliation: Department of Neuroimaging, University of Tübingen, Tübingen, Germany; High-Field MR Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Ehses
authors.affiliation: Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Blaimer
authors.affiliation: Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany; Department of Experimental Physics 5, Universität Würzburg, Würzburg, Germany.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Jakob
authors.affiliation: Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany.
authors.forename: Felix A
authors.initials: FA
authors.lastname: Breuer
mesh_terms: D000465:Algorithms; D016880:Anisotropy; D016477:Artifacts; D001921:Brain / Q000473:pathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007719:Knee Joint / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
keywords: 3D isotropic; 3D-isotrop; Entfernung von Bandingartefakten; Radial imaging; Radiale Bildgebung; SSFP sequences; SSFP-Sequenzen; banding removal