title: Segmented golden ratio radial reordering with variable temporal resolution for dynamic cardiac MRI.
abstract: Golden ratio (GR) radial reordering allows for retrospective choice of temporal resolution by providing a near-uniform k-space sampling within any reconstruction window. However, when applying GR to electrocardiogram (ECG)-gated cardiac imaging, the k-space coverage may not be as uniform because a single reconstruction window is broken into several temporally isolated ones. The goal of this study was to investigate the image artifacts caused by applying GR to ECG-gated cardiac imaging and to propose a segmented GR method to address this issue.
  
  
  
  Computer simulation and phantom experiments were used to evaluate the image artifacts resulting from three k-space sampling patterns (ie, uniform radial, conventional GR, and segmented GR). Two- and three-dimensional cardiac cine images were acquired in seven healthy subjects. Imaging artifacts due to k-space sampling nonuniformity were graded on a 5-point scale by an experienced cardiac imaging reader.
  
  
  
  Segmented GR provides more uniform k-space sampling that is independent of heart-rate variation than conventional GR. Cardiac cine images using segmented GR have significantly higher and more reliable image quality than conventional GR.
  
  
  
  Segmented GR successfully addresses the nonuniform sampling that occurs with combining conventional GR with ECG gating. This technique can potentially be applied to any ECG-gated cardiac imaging application to allow for retrospective selection of a reconstruction window. Magn Reson Med 76:94-103, 2016. © 2015 Wiley Periodicals, Inc.
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA.|Department of Bioengineering, University of California, Los Angeles, California, USA.
authors.forename: Fei
authors.initials: F
authors.lastname: Han
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA.|Department of Bioengineering, University of California, Los Angeles, California, USA.
authors.forename: Ziwu
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA.
authors.forename: Stanislas
authors.initials: S
authors.lastname: Rapacchi
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA.|Division of Cardiology, VA Greater Los Angeles Healthcare System and David Geffen School of Medicine, University of California, Los Angeles, California, USA.
authors.forename: Kim-Lien
authors.initials: KL
authors.lastname: Nguyen
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA.
authors.forename: J Paul
authors.initials: JP
authors.lastname: Finn
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA.|Biomedical Physics Inter-Departmental Graduate Program, University of California, Los Angeles, California, USA.
authors.forename: Peng
authors.initials: P
authors.lastname: Hu
mesh_terms: D000465:Algorithms; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
keywords: RF golden angle radial; cardiac MRI; golden ratio; segmented k-space