title: Cardiac C-arm computed tomography using a 3D + time ROI reconstruction method with spatial and temporal regularization.
abstract: OBJECTIVE
  Reconstruction of the beating heart in 3D + time in the catheter laboratory using only the available C-arm system would improve diagnosis, guidance, device sizing, and outcome control for intracardiac interventions, e.g., electrophysiology, valvular disease treatment, structural or congenital heart disease. To obtain such a reconstruction, the patient's electrocardiogram (ECG) must be recorded during the acquisition and used in the reconstruction. In this paper, the authors present a 4D reconstruction method aiming to reconstruct the heart from a single sweep 10 s acquisition.
  
  
  METHODS
  The authors introduce the 4D RecOnstructiOn using Spatial and TEmporal Regularization (short 4D ROOSTER) method, which reconstructs all cardiac phases at once, as a 3D + time volume. The algorithm alternates between a reconstruction step based on conjugate gradient and four regularization steps: enforcing positivity, averaging along time outside a motion mask that contains the heart and vessels, 3D spatial total variation minimization, and 1D temporal total variation minimization.
  
  
  RESULTS
  4D ROOSTER recovers the different temporal representations of a moving Shepp and Logan phantom, and outperforms both ECG-gated simultaneous algebraic reconstruction technique and prior image constrained compressed sensing on a clinical case. It generates 3D + time reconstructions with sharp edges which can be used, for example, to estimate the patient's left ventricular ejection fraction.
  
  
  CONCLUSIONS
  4D ROOSTER can be applied for human cardiac C-arm CT, and potentially in other dynamic tomography areas. It can easily be adapted to other problems as regularization is decoupled from projection and back projection.
authors: Université de Lyon, CREATIS; CNRS UMR5220; Inserm U1044; INSA-Lyon; Université Lyon 1, F-69621 Villeurbanne Cedex, France; and Philips Research Medisys, 33 rue de Verdun, 92156 Suresnes, France.
authors: Cyril
authors: C
authors: Mory
authors: Philips Research Medisys, 33 rue de Verdun, 92156 Suresnes, France.
authors: Vincent
authors: V
authors: Auvray
authors: Philips Research Medisys, 33 rue de Verdun, 92156 Suresnes, France.
authors: Bo
authors: B
authors: Zhang
authors: Philips Research, Röntgenstrasse 24-26, D-22335 Hamburg, Germany.
authors: Michael
authors: M
authors: Grass
authors: Philips Research, Röntgenstrasse 24-26, D-22335 Hamburg, Germany.
authors: Dirk
authors: D
authors: Schäfer
authors: Department of Medicine, Division of Cardiology, University of Colorado Denver, 12605 East 16th Avenue, Aurora, Colorado 80045.
authors: S James
authors: SJ
authors: Chen
authors: Department of Medicine, Division of Cardiology, University of Colorado Denver, 12605 East 16th Avenue, Aurora, Colorado 80045.
authors: John D
authors: JD
authors: Carroll
authors: Université de Lyon, CREATIS; CNRS UMR5220; Inserm U1044; INSA-Lyon; Université Lyon 1; and Centre Léon Bérard, 28 rue Laënnec, F-69373 Lyon, France.
authors: Simon
authors: S
authors: Rit
authors: Université de Lyon, CREATIS; CNRS UMR5220; Inserm U1044; INSA-Lyon; Université Lyon 1, F-69621 Villeurbanne Cedex, France; and X-ray Imaging Group, European Synchrotron, Radiation Facility, BP 220, F-38043 Grenoble Cedex, France.
authors: Françoise
authors: F
authors: Peyrin
authors: Université de Lyon, CREATIS; CNRS UMR5220; Inserm U1044; INSA-Lyon; Université Lyon 1; and Hospices Civils de Lyon, 28 Avenue du Doyen Jean Lépine, 69500 Bron, France.
authors: Philippe
authors: P
authors: Douek
authors: Université de Lyon, CREATIS; CNRS UMR5220; Inserm U1044; INSA-Lyon; Université Lyon 1; and Hospices Civils de Lyon, 28 Avenue du Doyen Jean Lépine, 69500 Bron, France.
authors: Loïc
authors: L
authors: Boussel
mesh_terms: D004562:Electrocardiography; D056973:Four-Dimensional Computed Tomography / Q000379:methods*; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D062211:Spatio-Temporal Analysis