title: Comparison of echocardiographic measurements of left ventricular volumes to full volume magnetic resonance imaging in normal and diseased rats.
abstract: BACKGROUND
  Clinical two-dimensional (2D) and clinical three-dimensional echocardiography are validated against cardiac magnetic resonance imaging (CMR), the gold standard for left ventricular (LV) volume measurement. In rodents, there is no widely accepted echocardiographic measure of whole LV volumes, and CMR measurements vary among studies. The aim of this study was to compare LV volumes by 2D echocardiography (using a hemisphere-cylinder [HC] model) with HC and full-volume (FV) CMR in normal and diseased rats to measure the impact of geometric models and imaging modalities.
  
  
  METHODS
  Rats (n = 27) underwent ascending aortic banding, myocardial infarction induction by either permanent left anterior descending coronary artery ligation or ischemia-reperfusion, and sham thoracotomy. Subsequently, end-diastolic volume, end-systolic volume, and ejection fraction were measured using an HC 2D echocardiographic model combining parasternal short-axis and long-axis measurements, and these were compared with HC and FV CMR.
  
  
  RESULTS
  Diseased groups showed LV dilatation and dysfunction. HC echocardiographic and FV CMR measures of end-diastolic volume, end-systolic volume, and ejection fraction were correlated. On Bland-Altman plots, end-diastolic volumes were concordant between both methods, while HC echocardiography underestimated end-systolic volumes, resulting in a modest overestimation of ejection fractions compared with FV CMR. Other 2D echocardiographic geometric models offered less concordance with FV CMR than HC. HC CMR overestimated LV volumes compared with FV CMR, while HC echocardiography underestimated HC CMR volumes. Echocardiography underestimated corresponding LV dimensions by CMR, particularly short axis.
  
  
  CONCLUSIONS
  Concordant measures of LV volume and function were obtained using (1) a relatively simple HC model of the left ventricle inclusive of two orthogonal 2D echocardiographic planes and (2) FV CMR in normal and diseased rats. The HC model appeared to compensate for the underestimation of LV dimensions by echocardiography.
authors.affiliation: Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
authors.forename: Teresa
authors.initials: T
authors.lastname: Arias
authors.forename: Jiqiu
authors.initials: J
authors.lastname: Chen
authors.forename: Zahi A
authors.initials: ZA
authors.lastname: Fayad
authors.forename: Valentin
authors.initials: V
authors.lastname: Fuster
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Hajjar
authors.forename: Elie R
authors.initials: ER
authors.lastname: Chemaly
mesh_terms: D000818:Animals; D004452:Echocardiography / Q000379:methods*; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D009203:Myocardial Infarction / Q000150:complications / Q000175:diagnosis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology
keywords: 2D; 3D; ANOVA; Analysis of variance; Animal models of disease; Animal ultrasound; CMR; Cardiac magnetic resonance imaging; EDV; EF; ESV; Echocardiography; Ejection fraction; End-diastolic volume; End-systolic volume; FV; Full-volume; HC; Hemisphere-cylinder; LV; Left ventricular; MI; Magnetic resonance imaging; Myocardial infarction; Rat; Three-dimensional; Two-dimensional