title: Whole-heart cine MRI in a single breath-hold--a compressed sensing accelerated 3D acquisition technique for assessment of cardiac function.
abstract: OBJECTIVE
  The aim of this study was to perform functional MR imaging of the whole heart in a single breath-hold using an undersampled 3 D trajectory for data acquisition in combination with compressed sensing for image reconstruction.
  
  
  METHODS
  Measurements were performed using an SSFP sequence on a 3 T whole-body system equipped with a 32-channel body array coil. A 3 D radial stack-of-stars sampling scheme was utilized enabling efficient undersampling of the k-space and thereby accelerating data acquisition. Compressed sensing was applied for the reconstruction of the missing data. A validation study was performed based on a fully sampled dataset acquired by standard Cartesian cine imaging of 2 D slices on a healthy volunteer. The results were investigated with regard to systematic errors and resolution losses possibly introduced by the developed reconstruction. Subsequently, the proposed technique was applied for in-vivo functional cardiac imaging of the whole heart in a single breath-hold of 27  s. The developed technique was tested on three healthy volunteers to examine its reproducibility.
  
  
  RESULTS
  By means of the results of the simulation (temporal resolution: 47  ms, spatial resolution: 1.4 × 1.4 × 8  mm, 3 D image matrix: 208 × 208 × 10), an overall acceleration factor of 10 has been found where the compressed sensing reconstructed image series shows only very low systematic errors and a slight in-plane resolution loss of 15 %. The results of the in-vivo study (temporal resolution: 40.5  ms, spatial resolution: 2.1 × 2.1 × 8  mm, 3 D image matrix: 224 × 224 × 12) performed with an acceleration factor of 10.7 confirm the overall good image quality of the presented technique for undersampled acquisitions.
  
  
  CONCLUSIONS
  The combination of 3 D radial data acquisition and model-based compressed sensing reconstruction allows high acceleration factors enabling cardiac functional imaging of the whole heart within only one breath-hold. The image quality in the simulated dataset and the in-vivo measurement highlights the great potential of the presented technique for an efficient assessment of cardiac functional parameters.
authors.affiliation: Institute of Radiology, University of Würzburg.
authors.forename: T
authors.initials: T
authors.lastname: Wech
authors.affiliation: Institute of Radiology, University of Würzburg.
authors.forename: W
authors.initials: W
authors.lastname: Pickl
authors.affiliation: Institute of Radiology, University of Würzburg.
authors.forename: J
authors.initials: J
authors.lastname: Tran-Gia
authors.affiliation: Institute of Radiology, University of Würzburg.
authors.forename: C
authors.initials: C
authors.lastname: Ritter
authors.affiliation: Institute of Radiology, University of Würzburg.
authors.forename: M
authors.initials: M
authors.lastname: Beer
authors.affiliation: Institute of Radiology, University of Würzburg.
authors.forename: D
authors.initials: D
authors.lastname: Hahn
authors.affiliation: Institute of Radiology, University of Würzburg.
authors.forename: H
authors.initials: H
authors.lastname: Köstler
mesh_terms: D000465:Algorithms; D062485:Breath Holding; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D044962:Data Compression / Q000379:methods*; D064368:Healthy Volunteers; D006334:Heart Function Tests / Q000379:methods; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016277:Ventricular Function, Left / Q000502:physiology*