title: Parametric visualization methods for the quantitative assessment of myocardial motion.
abstract: OBJECTIVE
  The authors performed this study to evaluate three-dimensional (3D) and four-dimensional (4D) techniques for quantifying and visualizing myocardial motion.
  
  
  METHODS
  The 4D method was performed by using 3D reconstructions of the complete, in vivo, canine heart before and after acute myocardial infarction. Images were obtained with the Dynamic Spatial Reconstructor (1-3) at 15 time points throughout one cardiac cycle. The authors used 0.75-mm-thick sections to allow creation of deformable models at each time point. For the 3D method, electron-beam computed tomographic reconstructions were obtained in anesthetized pigs from eight adjacent short-axis sections of the left ventricle. Data were acquired before and after selective microembolization of the left anterior descending coronary artery at 11 time points throughout one complete cardiaccycle. The authors used 8-mm-thick sections, which did not enable the use of the volumetric 4D approach with deformable models. For the 3D method, images were processed by radially dividing the tomographic images into small circumferential sectors. Color encoding was used for the derived local magnitudes of wall dynamics.
  
  
  RESULTS
  The 4D method provided endocardial peak velocities, excursions, and strains throughout systole and diastole. The 3D method provided regional thickness or regional rates of left ventricular wall thickening throughout the cardiac cycle.
  
  
  CONCLUSIONS
  Functional parametric maps of disturbances in regional contractility and relaxation facilitate appreciation of the effect of altered structure-to-function relationships in the myocardium.
authors.affiliation: Biomedical Imaging Resource, Mayo Foundation, 200 First St SW, Rochester, MN 55905, USA.
authors.forename: Christian D
authors.initials: CD
authors.lastname: Eusemann
authors.forename: Erik L
authors.initials: EL
authors.lastname: Ritman
authors.forename: Richard A
authors.initials: RA
authors.lastname: Robb
mesh_terms: D000818:Animals; D003116:Color; D004285:Dogs; D006321:Heart / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D006334:Heart Function Tests; D006801:Humans; D021621:Imaging, Three-Dimensional; D008953:Models, Anatomic; D013552:Swine; D014057:Tomography, X-Ray Computed