title: Self-navigation with compressed sensing for 2D translational motion correction in free-breathing coronary MRI: a feasibility study.
abstract: OBJECTIVE
  Respiratory motion correction remains a challenge in coronary magnetic resonance imaging (MRI) and current techniques, such as navigator gating, suffer from sub-optimal scan efficiency and ease-of-use. To overcome these limitations, an image-based self-navigation technique is proposed that uses "sub-images" and compressed sensing (CS) to obtain translational motion correction in 2D. The method was preliminarily implemented as a 2D technique and tested for feasibility for targeted coronary imaging.
  
  
  METHODS
  During a 2D segmented radial k-space data acquisition, heavily undersampled sub-images were reconstructed from the readouts collected during each cardiac cycle. These sub-images may then be used for respiratory self-navigation. Alternatively, a CS reconstruction may be used to create these sub-images, so as to partially compensate for the heavy undersampling. Both approaches were quantitatively assessed using simulations and in vivo studies, and the resulting self-navigation strategies were then compared to conventional navigator gating.
  
  
  RESULTS
  Sub-images reconstructed using CS showed a lower artifact level than sub-images reconstructed without CS. As a result, the final image quality was significantly better when using CS-assisted self-navigation as opposed to the non-CS approach. Moreover, while both self-navigation techniques led to a 69% scan time reduction (as compared to navigator gating), there was no significant difference in image quality between the CS-assisted self-navigation technique and conventional navigator gating, despite the significant decrease in scan time.
  
  
  CONCLUSIONS
  CS-assisted self-navigation using 2D translational motion correction demonstrated feasibility of producing coronary MRA data with image quality comparable to that obtained with conventional navigator gating, and does so without the use of additional acquisitions or motion modeling, while still allowing for 100% scan efficiency and an improved ease-of-use. In conclusion, compressed sensing may become a critical adjunct for 2D translational motion correction in free-breathing cardiac imaging with high spatial resolution. An expansion to modern 3D approaches is now warranted.
authors.affiliation: Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, VD, Switzerland; Center for Biomedical Imaging (CIBM), Lausanne, VD, Switzerland.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Bonanno
authors.affiliation: Institute of Electrical Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, VD, Switzerland.
authors.forename: Gilles
authors.initials: G
authors.lastname: Puy
authors.affiliation: Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, VD, Switzerland; Center for Biomedical Imaging (CIBM), Lausanne, VD, Switzerland; Institute of Electrical Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, VD, Switzerland; Department of Radiology and Medical Informatics, University of Geneva (UniGE), Genève, GE, Switzerland; Institute of Sensors, Signals & Systems, Heriot Watt University, Edinburgh, United Kingdom.
authors.forename: Yves
authors.initials: Y
authors.lastname: Wiaux
authors.affiliation: Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, VD, Switzerland; Center for Biomedical Imaging (CIBM), Lausanne, VD, Switzerland.
authors.forename: Ruud B
authors.initials: RB
authors.lastname: van Heeswijk
authors.affiliation: Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, VD, Switzerland; Center for Biomedical Imaging (CIBM), Lausanne, VD, Switzerland; Advanced Clinical Imaging Technology, Siemens Healthcare IM BM PI, Lausanne, Switzerland.
authors.forename: Davide
authors.initials: D
authors.lastname: Piccini
authors.affiliation: Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, VD, Switzerland; Center for Biomedical Imaging (CIBM), Lausanne, VD, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Stuber
mesh_terms: D000328:Adult; D000465:Algorithms; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D044962:Data Compression / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D009038:Motion; D011859:Radiography; D015203:Reproducibility of Results; D012119:Respiration; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D055815:Young Adult