title: Single breath-hold 3D measurement of left atrial volume using compressed sensing cardiovascular magnetic resonance and a non-model-based reconstruction approach.
abstract: BACKGROUND
  Left atrial (LA) dilatation is associated with a large variety of cardiac diseases. Current cardiovascular magnetic resonance (CMR) strategies to measure LA volumes are based on multi-breath-hold multi-slice acquisitions, which are time-consuming and susceptible to misregistration.
  
  
  OBJECTIVE
  To develop a time-efficient single breath-hold 3D CMR acquisition and reconstruction method to precisely measure LA volumes and function.
  
  
  METHODS
  A highly accelerated compressed-sensing multi-slice cine sequence (CS-cineCMR) was combined with a non-model-based 3D reconstruction method to measure LA volumes with high temporal and spatial resolution during a single breath-hold. This approach was validated in LA phantoms of different shapes and applied in 3 patients. In addition, the influence of slice orientations on accuracy was evaluated in the LA phantoms for the new approach in comparison with a conventional model-based biplane area-length reconstruction. As a reference in patients, a self-navigated high-resolution whole-heart 3D dataset (3D-HR-CMR) was acquired during mid-diastole to yield accurate LA volumes.
  
  
  RESULTS
  Phantom studies. LA volumes were accurately measured by CS-cineCMR with a mean difference of -4.73 ± 1.75 ml (-8.67 ± 3.54%, r2 = 0.94). For the new method the calculated volumes were not significantly different when different orientations of the CS-cineCMR slices were applied to cover the LA phantoms. Long-axis "aligned" vs "not aligned" with the phantom long-axis yielded similar differences vs the reference volume (-4.87 ± 1.73 ml vs. -4.45 ± 1.97 ml, p = 0.67) and short-axis "perpendicular" vs. "not-perpendicular" with the LA long-axis (-4.72 ± 1.66 ml vs. -4.75 ± 2.13 ml; p = 0.98). The conventional bi-plane area-length method was susceptible for slice orientations (p = 0.0085 for the interaction of "slice orientation" and "reconstruction technique", 2-way ANOVA for repeated measures). To use the 3D-HR-CMR as the reference for LA volumes in patients, it was validated in the LA phantoms (mean difference: -1.37 ± 1.35 ml, -2.38 ± 2.44%, r2 = 0.97). Patient study: The CS-cineCMR LA volumes of the mid-diastolic frame matched closely with the reference LA volume (measured by 3D-HR-CMR) with a difference of -2.66 ± 6.5 ml (3.0% underestimation; true LA volumes: 63 ml, 62 ml, and 395 ml). Finally, a high intra- and inter-observer agreement for maximal and minimal LA volume measurement is also shown.
  
  
  CONCLUSIONS
  The proposed method combines a highly accelerated single-breathhold compressed-sensing multi-slice CMR technique with a non-model-based 3D reconstruction to accurately and reproducibly measure LA volumes and function.
authors.affiliation: Laboratory of Hemodynamics and Cardiovascular Technology, Institute of Bioengineering, Swiss Federal Institute of Technology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland. orestis.vardoulis@epfl.ch.
authors.forename: Orestis
authors.initials: O
authors.lastname: Vardoulis
authors.affiliation: Division of Cardiology and Cardiac MR Center, University Hospital of Lausanne (CHUV), Lausanne, Switzerland. pierre.monney@chuv.ch.
authors.forename: Pierre
authors.initials: P
authors.lastname: Monney
authors.affiliation: Computer Graphics lab, ETH Zurich & Disney Research Zurich, Zurich, Switzerland. amit.bermano@disneyresearch.com.
authors.forename: Amit
authors.initials: A
authors.lastname: Bermano
authors.affiliation: Geometric Modeling and Industrial Geometry group, Vienna University of Technology, Vienna, Austria. avaxman@geometrie.tuwien.ac.at.
authors.forename: Amir
authors.initials: A
authors.lastname: Vaxman
authors.affiliation: Jacobs Technion-Cornell Institute at Cornell Tech, New York, USA. gotsman@cs.technion.ac.il.
authors.forename: Craig
authors.initials: C
authors.lastname: Gotsman
authors.affiliation: University of Fribourg, Biomedical Sciences, Fribourg, Switzerland. janineschwitter@bluewin.ch.
authors.forename: Janine
authors.initials: J
authors.lastname: Schwitter
authors.affiliation: Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland. matthias.stuber@chuv.ch.|Center for Biomedical Imaging, Lausanne, Switzerland. matthias.stuber@chuv.ch.
authors.forename: Matthias
authors.initials: M
authors.lastname: Stuber
authors.affiliation: Laboratory of Hemodynamics and Cardiovascular Technology, Institute of Bioengineering, Swiss Federal Institute of Technology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland. nikolaos.stergiopulos@epfl.ch.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Stergiopulos
authors.affiliation: Division of Cardiology and Cardiac MR Center, University Hospital of Lausanne (CHUV), Lausanne, Switzerland. jurg.schwitter@chuv.ch.
authors.forename: Juerg
authors.initials: J
authors.lastname: Schwitter
mesh_terms: D000369:Aged, 80 and over; D000465:Algorithms; D016279:Atrial Function, Left; D062485:Breath Holding; D044962:Data Compression; D005260:Female; D006325:Heart Atria / Q000473:pathology / Q000503:physiopathology; D006331:Heart Diseases / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D015588:Observer Variation; D019047:Phantoms, Imaging; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013997:Time Factors; D055815:Young Adult