title: A new framework for interleaved scanning in cardiovascular MR: Application to image-based respiratory motion correction in coronary MR angiography.
abstract: OBJECTIVE
  To describe a new framework for interleaving scans and demonstrate its usefulness for image-based respiratory motion correction in whole heart coronary MR angiography (CMRA).
  
  
  METHODS
  Scan interleaving using the proposed approach was achieved by switching between separately defined, independent scans at arbitrary time points during their execution, using a generic function call. The scan interleaving framework was used to perform scan interleaving for image-based respiratory navigation of CMRA with spiral, radial, and Cartesian echo-planar imaging (EPI) navigator k-space trajectories. Eight healthy volunteers were scanned.
  
  
  RESULTS
  Improved coronary vessel sharpness and visual scores were obtained using spiral and Cartesian EPI navigators compared with radial navigators.
  
  
  CONCLUSIONS
  The usefulness of the proposed scan interleaving framework was demonstrated for image-based respiratory motion correction. It facilitated more direct comparisons of image navigator acquisitions with different k-space trajectories. Furthermore, we could demonstrate that spiral and Cartesian EPI navigators may be particularly suitable for image-based motion correction, as they provide improved motion correction and high navigator apparent signal-to-noise ratio while spending very little magnetization, thereby minimizing saturation effects.
authors.affiliation: Division of Imaging Sciences & Biomedical Engineering, King's College London, London, UK; Wellcome Trust and EPSRC Medical Engineering Center, King's College London, London, UK; BHF Centre of Excellence, King's College London, London, UK; NIHR Biomedical Research Centre, King's College London, London, UK.
authors.forename: Markus
authors.initials: M
authors.lastname: Henningsson
authors.forename: Giel
authors.initials: G
authors.lastname: Mens
authors.forename: Peter
authors.initials: P
authors.lastname: Koken
authors.forename: Jouke
authors.initials: J
authors.lastname: Smink
authors.forename: Rene M
authors.initials: RM
authors.lastname: Botnar
mesh_terms: D000328:Adult; D000465:Algorithms; D016477:Artifacts; D017023:Coronary Angiography / Q000379:methods; D003331:Coronary Vessels / Q000033:anatomy & histology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D009038:Motion; D010363:Pattern Recognition, Automated / Q000379:methods; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity
keywords: cardiovascular MRI; interleaved scanning; respiratory motion correction