title: Whole-heart coronary MRA with 3D affine motion correction using 3D image-based navigation.
abstract: OBJECTIVE
  Robust motion correction is necessary to minimize respiratory motion artefacts in coronary MR angiography (CMRA). The state-of-the-art method uses a 1D feet-head translational motion correction approach, and data acquisition is limited to a small window in the respiratory cycle, which prolongs the scan by a factor of 2-3. The purpose of this work was to implement 3D affine motion correction for Cartesian whole-heart CMRA using a 3D navigator (3D-NAV) to allow for data acquisition throughout the whole respiratory cycle.
  
  
  METHODS
  3D affine transformations for different respiratory states (bins) were estimated by using 3D-NAV image acquisitions which were acquired during the startup profiles of a steady-state free precession sequence. The calculated 3D affine transformations were applied to the corresponding high-resolution Cartesian image acquisition which had been similarly binned, to correct for respiratory motion between bins.
  
  
  RESULTS
  Quantitative and qualitative comparisons showed no statistical difference between images acquired with the proposed method and the reference method using a diaphragmatic navigator with a narrow gating window.
  
  
  CONCLUSIONS
  We demonstrate that 3D-NAV and 3D affine correction can be used to acquire Cartesian whole-heart 3D coronary artery images with 100% scan efficiency with similar image quality as with the state-of-the-art gated and corrected method with approximately 50% scan efficiency.
authors: Division of Imaging Sciences & Biomedical Engineering, King's College London, London, UK.
authors: Markus
authors: M
authors: Henningsson
authors: Claudia
authors: C
authors: Prieto
authors: Amedeo
authors: A
authors: Chiribiri
authors: Ghislain
authors: G
authors: Vaillant
authors: Reza
authors: R
authors: Razavi
authors: René M
authors: RM
authors: 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*; D009038:Motion; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D015203:Reproducibility of Results; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity
keywords: 3D affine transform; phase reordering; respiratory motion correction; whole-heart CMRA