title: Real-time, three-dimensional echocardiography: feasibility of dynamic right ventricular volume measurement with saline contrast.
abstract: BACKGROUND
  The asymmetry and complex shape of the right ventricle have made it difficult to determine right ventricular (RV) volume with 2-dimensional echocardiography. Three-dimensional cardiac imaging improves visualization of cardiac anatomy but is also complex and time consuming. A newly developed volumetric scanning system holds promise of obviating past limitations.
  
  
  METHODS
  Real-time, transthoracic 3-dimensional echocardiographic images of the right ventricle were obtained with a high-speed volumetric ultrasound system that uses a 16:1 parallel processing schema from a 2.5 MHz matrix phased-array scanner to interrogate an entire pyramidal volume in real time. The instrumentation was used to measure RV volume in 8 excised canine hearts; dynamic real-time 3-dimensional images were also obtained from 14 normal subjects.
  
  
  RESULTS
  Three-dimensional images were obtained in vitro and in vivo during intravenous hand-agitated saline injection to determine RV volumes. The RV volumes by real-time 3-dimensional echocardiography are well correlated with those of drained in vitro (y = 1.26x - 9.92, r = 0.97, P <.0001, standard error of the estimate = 3.26 mL). For human subjects, the end-diastolic and end-systolic RV volumes were calculated by tracing serial cross-sectional, inclined C scans; functional data were validated by comparing the scans with conventional 2-dimensional echocardiographic indexes of left ventricular stroke volume.
  
  
  CONCLUSIONS
  These data indicate that RV volume measurements of excised heart by real-time 3-dimensional echocardiography are accurate and that beat-to-beat RV quantitative measurement applying this imaging method is possible. The new application of real-time 3-dimensional echocardiography presents the opportunity to develop new descriptors of cardiac performance.
authors.affiliation: Division of Medicine and Biomedical Engineering, The Center for Emerging Cardiovascular Technologies, Duke University, Durham, NC, USA.
authors.forename: T
authors.initials: T
authors.lastname: Ota
authors.forename: C E
authors.initials: CE
authors.lastname: Fleishman
authors.forename: M
authors.initials: M
authors.lastname: Strub
authors.forename: G
authors.initials: G
authors.lastname: Stetten
authors.forename: C J
authors.initials: CJ
authors.lastname: Ohazama
authors.forename: O T
authors.initials: OT
authors.lastname: von Ramm
authors.forename: J
authors.initials: J
authors.lastname: Kisslo
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage*; D004285:Dogs; D019560:Echocardiography, Three-Dimensional; D005240:Feasibility Studies; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007275:Injections, Intravenous; D012016:Reference Values; D015203:Reproducibility of Results; D012965:Sodium Chloride / Q000008:administration & dosage; D016278:Ventricular Function, Right / Q000502:physiology*
chemical_list: D003287:Contrast Media; D012965:Sodium Chloride