title: Improved assessment of mitral valve stenosis by volumetric real-time three-dimensional echocardiography.
abstract: OBJECTIVE
  This study was performed to determine the feasibility, accuracy and reproducibility of real-time volumetric three-dimensional echocardiography (3-D echo) for the estimation of mitral valve area in patients with mitral valve stenosis.
  
  
  BACKGROUND
  Planimetry of the mitral valve area (MVA) by two-dimensional echocardiography (2-D echo) requires a favorable parasternal acoustic window and depends on operator skill. Transthoracic volumetric 3-D echo allows reconstruction of multiple 2-D planes in any desired orientation and is not limited to parasternal acquisition, and could thus enhance the accuracy and feasibility of calculating MVA.
  
  
  METHODS
  In 48 patients with mitral stenosis (40 women; mean age 61 +/- 13 years) MVA was determined by planimetry using volumetric 3-D echo and compared with measurements obtained by 2-D echo and Doppler pressure half-time (PHT). All measurements were performed by two independent observers. Volumetric data were acquired from an apical view.
  
  
  RESULTS
  Although 2-D echo allowed planimetry of the mitral valve in 43 of 48 patients (89%), calculation of the MVA was possible in all patients when 3-D echo was used. Mitral valve area by 3-D echo correlated well with MVA by 2-D echo (r = 0.93, mean difference, 0.09 +/- 0.14 cm2) and by PHT (r = 0.87, mean difference, 0.16 +/- 0.19 cm2). Interobserver variability was significantly less for 3-D echo than for 2-D echo (SD 0.08cm2 versus SD 0.23cm2, p < 0.001). Furthermore, it was much easier and faster to define the image plane with the smallest orifice area when 3-D echo was used.
  
  
  CONCLUSIONS
  Transthoracic real-time volumetric 3-D echo provides accurate and highly reproducible measurements of mitral valve area and can easily be performed from an apical approach.
authors.affiliation: Department of Cardiology, University of Vienna, Austria. thomas.binder@univie.ac.at
authors.forename: T M
authors.initials: TM
authors.lastname: Binder
authors.forename: R
authors.initials: R
authors.lastname: Rosenhek
authors.forename: G
authors.initials: G
authors.lastname: Porenta
authors.forename: G
authors.initials: G
authors.lastname: Maurer
authors.forename: H
authors.initials: H
authors.lastname: Baumgartner
mesh_terms: D002306:Cardiac Volume / Q000502:physiology*; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging*; D008946:Mitral Valve Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015588:Observer Variation; D015203:Reproducibility of Results