title: Automatic 3D aortic annulus sizing by computed tomography in the planning of transcatheter aortic valve implantation.
abstract: BACKGROUND
  Accurate imaging assessment of aortic annulus (AoA) dimension is paramount to decide on the correct transcatheter heart valve (THV) size for patients undergoing transcatheter aortic valve implantation (TAVI). We evaluated the feasibility and accuracy of a novel automatic framework for multidetector row computed tomography (MDCT)-based TAVI planning.
  
  
  METHODS
  Among 122 consecutive patients undergoing TAVI and retrospectively reviewed for this study, 104 patients with preoperative MDCT of sufficient quality were enrolled and analyzed with the proposed software. Fully automatic (FA) and semi-automatic (SA) AoA measurements were compared to manual measurements, with both automated and manual-based interobserver variability (IOV) being assessed. Finally, the effect of these measures on hypothetically selected THV size was evaluated against the implanted size, as well as with respect to manually-derived sizes.
  
  
  RESULTS
  FA analysis was feasible in 92.3% of the cases, increasing to 100% if using the SA approach. Automatically-extracted measurements showed excellent agreement with manually-derived ones, with small biases and narrow limits of agreement, and comparable to the interobserver agreement. The SA approach presented a statistically lower IOV than manual analysis, showing the potential to reduce interobserver sizing disagreements. Moreover, the automated approaches displayed close agreement with the implanted sizes, similar to the ones obtained by the experts.
  
  
  CONCLUSIONS
  The proposed automatic framework provides an accurate and robust tool for AoA measurements and THV sizing in patients undergoing TAVI.
authors.affiliation: Dept. of Cardiovascular Sciences, KU Leuven, Leuven, Belgium; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal; Algoritmi Center, School of Engineering, University of Minho, Guimarães, Portugal. Electronic address: sandroqueiros@med.uminho.pt.
authors.forename: Sandro
authors.initials: S
authors.lastname: Queirós
authors.affiliation: Dept. of Cardiovascular Sciences, KU Leuven, Leuven, Belgium; Dept. of Cardiovascular Diseases, University Hospital Leuven, Leuven, Belgium. Electronic address: christophe.dubois@uzleuven.be.
authors.forename: Christophe
authors.initials: C
authors.lastname: Dubois
authors.affiliation: Dept. of Cardiovascular Sciences, KU Leuven, Leuven, Belgium; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal; INEGI, Faculty of Engineering, University of Porto, Porto, Portugal. Electronic address: pedromorais@med.uminho.pt.
authors.forename: Pedro
authors.initials: P
authors.lastname: Morais
authors.affiliation: Dept. of Cardiovascular Sciences, KU Leuven, Leuven, Belgium; Dept. of Cardiovascular Diseases, University Hospital Leuven, Leuven, Belgium. Electronic address: tom.adriaenssens@uzleuven.be.
authors.forename: Tom
authors.initials: T
authors.lastname: Adriaenssens
authors.affiliation: Algoritmi Center, School of Engineering, University of Minho, Guimarães, Portugal. Electronic address: jaime@dei.uminho.pt.
authors.forename: Jaime C
authors.initials: JC
authors.lastname: Fonseca
authors.affiliation: ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal; DIGARC - Polytechnic Institute of Cávado and Ave, Barcelos, Portugal. Electronic address: jvilaca@ipca.pt.
authors.forename: João L
authors.initials: JL
authors.lastname: Vilaça
authors.affiliation: Dept. of Cardiovascular Sciences, KU Leuven, Leuven, Belgium. Electronic address: jan.dhooge@uzleuven.be.
authors.forename: Jan
authors.initials: J
authors.lastname: D'hooge
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging*; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000628:therapy*; D001331:Automation; D006328:Cardiac Catheterization / Q000295:instrumentation* / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D008297:Male; D015588:Observer Variation; D018579:Patient Selection; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012984:Software; D014057:Tomography, X-Ray Computed
keywords: Aortic valve sizing; Computed tomography; Fully automatic analysis; Semi-automatic analysis; TAVI