title: Cardiovascular magnetic resonance compatible physical model of the left ventricle for multi-modality characterization of wall motion and hemodynamics.
abstract: BACKGROUND
  The development of clinically applicable fluid-structure interaction (FSI) models of the left heart is inherently challenging when using in vivo cardiovascular magnetic resonance (CMR) data for validation, due to the lack of a well-controlled system where detailed measurements of the ventricular wall motion and flow field are available a priori. The purpose of this study was to (a) develop a clinically relevant, CMR-compatible left heart physical model; and (b) compare the left ventricular (LV) volume reconstructions and hemodynamic data obtained using CMR to laboratory-based experimental modalities.
  
  
  METHODS
  The LV was constructed from optically clear flexible silicone rubber. The geometry was based off a healthy patient's LV geometry during peak systole. The LV phantom was attached to a left heart simulator consisting of an aorta, atrium, and systemic resistance and compliance elements. Experiments were conducted for heart rate of 70 bpm. Wall motion measurements were obtained using high speed stereo-photogrammetry (SP) and cine-CMR, while flow field measurements were obtained using digital particle image velocimetry (DPIV) and phase-contrast magnetic resonance (PC-CMR).
  
  
  RESULTS
  The model reproduced physiologically accurate hemodynamics (aortic pressure = 120/80 mmHg; cardiac output = 3.5 L/min). DPIV and PC-CMR results of the center plane flow within the ventricle matched, both qualitatively and quantitatively, with flow from the atrium into the LV having a velocity of about 1.15 m/s for both modalities. The normalized LV volume through the cardiac cycle computed from CMR data matched closely to that from SP. The mean difference between CMR and SP was 5.5 ± 3.7%.
  
  
  CONCLUSIONS
  The model presented here can thus be used for the purposes of: (a) acquiring CMR data for validation of FSI simulations, (b) determining accuracy of cine-CMR reconstruction methods, and
authors.affiliation: School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA. iokafor3@gatech.edu.
authors.forename: Ikechukwu U
authors.initials: IU
authors.lastname: Okafor
authors.affiliation: School of Mechanical & Aerospace Engineering, Oklahoma State University, Stillwater, OK, USA. askrish@okstate.edu.
authors.forename: Arvind
authors.initials: A
authors.lastname: Santhanakrishnan
authors.affiliation: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA. bchaffins@gmail.com.
authors.forename: Brandon D
authors.initials: BD
authors.lastname: Chaffins
authors.affiliation: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA. lucia.mirabell@gmail.com.
authors.forename: Lucia
authors.initials: L
authors.lastname: Mirabella
authors.affiliation: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA. jnoshin@emory.edu.|Department of Radiology and Imaging Sciences, School of Medicine, Emory University, Atlanta, GA, USA. jnoshin@emory.edu.
authors.forename: John N
authors.initials: JN
authors.lastname: Oshinski
authors.affiliation: School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA. ajit.yoganathan@bme.gatech.edu.|Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA. ajit.yoganathan@bme.gatech.edu.
authors.forename: Ajit P
authors.initials: AP
authors.lastname: Yoganathan
mesh_terms: D062186:Arterial Pressure; D001696:Biomechanical Phenomena; D002302:Cardiac Output; D006339:Heart Rate; D006352:Heart Ventricles / Q000033:anatomy & histology*; D006439:Hemodynamics; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000295:instrumentation*; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D009200:Myocardial Contraction; D019047:Phantoms, Imaging; D010780:Photogrammetry; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012212:Rheology; D012826:Silicone Elastomers; D013997:Time Factors; D016277:Ventricular Function, Left
chemical_list: D012826:Silicone Elastomers