title: Mapping right ventricular myocardial mechanics using 3D cine DENSE cardiovascular magnetic resonance.
abstract: BACKGROUND
  The mechanics of the right ventricle (RV) are not well understood as studies of the RV have been limited. This is, in part, due to the RV's thin wall, asymmetric geometry and irregular motion. However, the RV plays an important role in cardiovascular function. This study aims to describe the complex mechanics of the healthy RV using three dimensional (3D) cine displacement encoding with stimulated echoes (DENSE) cardiovascular magnetic resonance (CMR).
  
  
  METHODS
  Whole heart 3D cine DENSE data were acquired from five healthy volunteers. Tailored post-processing algorithms for RV mid-wall tissue tracking and strain estimation are presented. A method for sub-dividing the RV into four regions according to anatomical land marks is proposed, and the temporal evolution of strain was assessed in these regions.
  
  
  RESULTS
  The 3D cine DENSE tissue tracking methods successfully capture the motion and deformation of the RV at a high spatial resolution in all volunteers. The regional Lagrangian peak surface strain and time to peak values correspond with previous studies using myocardial tagging, DENSE and strain encoded CMR. The inflow region consistently displays lower peak strains than the apical and outflow regions, and the time to peak strains suggest RV mechanical activation in the following order: inflow, outflow, mid, then apex.
  
  
  CONCLUSIONS
  Model-free techniques have been developed to study the myocardial mechanics of the RV at a high spatial resolution using 3D cine DENSE CMR. The consistency of the regional RV strain patterns across healthy subjects is encouraging and the techniques may have clinical utility in assessing disrupted RV mechanics in the diseased heart.
authors.affiliation: MRC/UCT Medical Imaging Research Unit, Department of Human Biology, University of Cape Town, Cape Town, South Africa.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Auger
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhong
authors.forename: Frederick H
authors.initials: FH
authors.lastname: Epstein
authors.forename: Bruce S
authors.initials: BS
authors.lastname: Spottiswoode
mesh_terms: D000328:Adult; D000465:Algorithms; D059925:Anatomic Landmarks; D001696:Biomechanical Phenomena; D006352:Heart Ventricles / Q000033:anatomy & histology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D019028:Magnetic Resonance Imaging, Cine; D008875:Middle Aged; D009200:Myocardial Contraction; D011237:Predictive Value of Tests; D012016:Reference Values; D013019:South Africa; D013314:Stress, Mechanical; D013997:Time Factors; D016278:Ventricular Function, Right; D055815:Young Adult