title: Semiautomatic, Quantitative Measurement of Aortic Valve Area Using CTA: Validation and Comparison with Transthoracic Echocardiography.
abstract: OBJECTIVE
  The aim of this work was to develop a fast and robust (semi)automatic segmentation technique of the aortic valve area (AVA) MDCT datasets.
  
  
  METHODS
  The algorithm starts with detection and cropping of Sinus of Valsalva on MPR image. The cropped image is then binarized and seed points are manually selected to create an initial contour. The contour moves automatically towards the edge of aortic AVA to obtain a segmentation of the AVA. AVA was segmented semiautomatically and manually by two observers in multiphase cardiac CT scans of 25 patients. Validation of the algorithm was obtained by comparing to Transthoracic Echocardiography (TTE). Intra- and interobserver variability were calculated by relative differences. Differences between TTE and MDCT manual and semiautomatic measurements were assessed by Bland-Altman analysis. Time required for manual and semiautomatic segmentations was recorded.
  
  
  RESULTS
  Mean differences from TTE were -0.19 (95% CI: -0.74 to 0.34) cm(2) for manual and -0.10 (95% CI: -0.45 to 0.25) cm(2) for semiautomatic measurements. Intra- and interobserver variability were 8.4 ± 7.1% and 27.6 ± 16.0% for manual, and 5.8 ± 4.5% and 16.8 ± 12.7% for semiautomatic measurements, respectively.
  
  
  CONCLUSIONS
  Newly developed semiautomatic segmentation provides an accurate, more reproducible, and faster AVA segmentation result.
authors.affiliation: Center for Medical Imaging North East Netherlands (CMI-NEN), Department of Radiology, University of Groningen, University Medical Center Groningen, P.O. Box 30001, 9700 RB Groningen, Netherlands.
authors.forename: V
authors.initials: V
authors.lastname: Tuncay
authors.affiliation: Department of Radiology, University of Groningen, University Medical Center, P.O. Box 30001, 9700 RB Groningen, Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Prakken
authors.affiliation: Center for Medical Imaging North East Netherlands (CMI-NEN), Department of Radiology, University of Groningen, University Medical Center Groningen, P.O. Box 30001, 9700 RB Groningen, Netherlands ; Department of Radiology, University of Groningen, University Medical Center, P.O. Box 30001, 9700 RB Groningen, Netherlands.
authors.forename: P M A
authors.initials: PM
authors.lastname: van Ooijen
authors.affiliation: Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3508 GA Utrecht, Netherlands.
authors.forename: R P J
authors.initials: RP
authors.lastname: Budde
authors.affiliation: Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3508 GA Utrecht, Netherlands.
authors.forename: T
authors.initials: T
authors.lastname: Leiner
authors.affiliation: Center for Medical Imaging North East Netherlands (CMI-NEN), Department of Radiology, University of Groningen, University Medical Center Groningen, P.O. Box 30001, 9700 RB Groningen, Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Oudkerk
mesh_terms: D000369:Aged, 80 and over; D000465:Algorithms; D001021:Aortic Valve / Q000000981:diagnostic imaging*; D001331:Automation; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D015588:Observer Variation; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*