title: Determination of volume-time curves for the right ventricle and its outflow tract for functional analyses.
abstract: OBJECTIVE
  The determination of right ventricular volumes and function is of increasing interest for the postoperative care of patients with congenital heart defects. The presentation of volumetry data in terms of volume-time curves allows a comprehensive functional assessment. By using manual contour tracing, the generation of volume-time curves is exceedingly time-consuming.
  
  
  METHODS
  This study describes a fast and precise method for determining volume-time curves for the right ventricle and for the right ventricular outflow tract. The method applies contour detection and includes a feature for identifying the right ventricular outflow tract volume. The segregation of the outflow tract is performed by four-dimensional curved smooth boundary surfaces defined by prespecified anatomical landmarks.
  
  
  RESULTS
  The comparison with manual contour tracing demonstrates that the method is accurate and improves the precision of the measurement. Compared to manual contour tracing the bias is <0.1% ± 4.1% (right ventricle) and -2.6% ± 20.0% (right ventricular outflow tract). The standard deviations of inter- and intraobserver variabilities for determining the volume of the right ventricular outflow tract are reduced to less than half the values of manual contour tracing. The time consumption per patient is reduced from 341 ± 80 min (right ventricle) and 56 ± 11 min (right ventricular outflow tract) using manual contour tracing to 46 ± 9 min for a combined analysis of right ventricle and right ventricular outflow tract.
  
  
  CONCLUSIONS
  The analysis of volume-time curves for the right ventricle and its outflow tract discloses new evaluation methods in clinical routine and science.
authors: Department of Congenital Heart Disease and Pediatric Cardiology, University Hospital Schleswig-Holstein, Kiel, Germany.
authors: Dominik D
authors: DD
authors: Gabbert
authors: Andreas
authors: A
authors: Entenmann
authors: Michael
authors: M
authors: Jerosch-Herold
authors: Felicitas
authors: F
authors: Frettlöh
authors: Christopher
authors: C
authors: Hart
authors: Inga
authors: I
authors: Voges
authors: Minh
authors: M
authors: Pham
authors: Ana
authors: A
authors: Andrade
authors: Eileen
authors: E
authors: Pardun
authors: P
authors: P
authors: Wegner
authors: Traudel
authors: T
authors: Hansen
authors: Hans-Heiner
authors: HH
authors: Kramer
authors: Carsten
authors: C
authors: Rickers
mesh_terms: D000465:Algorithms; D002306:Cardiac Volume; D006330:Heart Defects, Congenital / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D006352:Heart Ventricles / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014694:Ventricular Outflow Obstruction / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*
keywords: cardiac MRI; segmentation; volume