title: Three-dimensional heart locator and compressed sensing for whole-heart MR angiography.
abstract: OBJECTIVE
  We sought to develop a whole-heart magnetic resonance angiography technique with three-dimensional (3D) respiratory motion compensation and reduced scan time.
  
  
  METHODS
  A novel respiratory motion compensation method was implemented that acquires a 1D navigator (NAV) and a low-resolution 3D-image of the heart (3D-LOC) just before the angiography data. The central 10% of SSFP k-space was fully acquired using NAV-gating, and then 10% of peripheral k-space was randomly undersampled to complete the scan. Spatial registration of the 3D-LOC information was used to correct the central and peripheral k-space lines for the bulk respiratory motion in three dimensions, and then the remaining k-space data was estimated using compressed sensing (CS). Ten volunteers each underwent two angiography acquisitions with 1 mm(3) resolution: (i) conventional NAV with CS, and (ii) the new 3D-LOC with CS.
  
  
  RESULTS
  Compared with conventional NAV, the new 3D-LOC with CS technique had a shorter scan time (4.8 ± 1.1 versus 6.3 ± 1.7 min; P < 0.001), better objective vessel sharpness for all three coronary arteries (P < 0.05), and no difference in subjective vessel sharpness for all three coronary arteries.
  
  
  CONCLUSIONS
  Compared with conventional NAV with CS, acceleration and respiratory motion correction using 3D-LOC with CS reduces scan time and improves objective vessel sharpness.
authors.affiliation: Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA.|Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Mehdi H
authors.initials: MH
authors.lastname: Moghari
authors.affiliation: Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA.
authors.forename: David
authors.initials: D
authors.lastname: Annese
authors.affiliation: Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA.|Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Tal
authors.initials: T
authors.lastname: Geva
authors.affiliation: Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA.|Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Powell
mesh_terms: D000328:Adult; D016477:Artifacts; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D064368:Healthy Volunteers; D006321:Heart / Q000000981:diagnostic imaging* / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography; D008297:Male; D009038:Motion; D019047:Phantoms, Imaging; D015203:Reproducibility of Results
keywords: compressed sensing; motion compensation; navigator; respiratory motion; whole-heart angiography