title: 3D/3D registration of coronary CTA and biplane XA reconstructions for improved image guidance.
abstract: OBJECTIVE
  The authors aim to improve image guidance during percutaneous coronary interventions of chronic total occlusions (CTO) by providing information obtained from computed tomography angiography (CTA) to the cardiac interventionist. To this end, the authors investigate a method to register a 3D CTA model to biplane reconstructions.
  
  
  METHODS
  The authors developed a method for registering preoperative coronary CTA with intraoperative biplane x-ray angiography (XA) images via 3D models of the coronary arteries. The models are extracted from the CTA and biplane XA images, and are temporally aligned based on CTA reconstruction phase and XA ECG signals. Rigid spatial alignment is achieved with a robust probabilistic point set registration approach using Gaussian mixture models (GMMs). This approach is extended by including orientation in the Gaussian mixtures and by weighting bifurcation points. The method is evaluated on retrospectively acquired coronary CTA datasets of 23 CTO patients for which biplane XA images are available.
  
  
  RESULTS
  The Gaussian mixture model approach achieved a median registration accuracy of 1.7 mm. The extended GMM approach including orientation was not significantly different (P>0.1) but did improve robustness with regards to the initialization of the 3D models.
  
  
  CONCLUSIONS
  The authors demonstrated that the GMM approach can effectively be applied to register CTA to biplane XA images for the purpose of improving image guidance in percutaneous coronary interventions.
authors.affiliation: Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus Medical Center, 3015 GE Rotterdam, The Netherlands.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Dibildox
authors.affiliation: Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus Medical Center, 3015 GE Rotterdam, The Netherlands.
authors.forename: Nora
authors.initials: N
authors.lastname: Baka
authors.affiliation: Pie Medical Imaging, 6227 AJ Maastricht, The Netherlands.
authors.forename: Mark
authors.initials: M
authors.lastname: Punt
authors.affiliation: Pie Medical Imaging, 6227 AJ Maastricht, The Netherlands.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Aben
authors.affiliation: Department of Cardiology, Erasmus Medical Center, 3015 GE Rotterdam, The Netherlands.
authors.forename: Carl
authors.initials: C
authors.lastname: Schultz
authors.affiliation: Quantitative Imaging Group, Faculty of Applied Sciences, Delft University of Technology, 2628 CJ Delft, The Netherlands and Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus Medical Center, 3015 GE Rotterdam, The Netherlands.
authors.forename: Wiro
authors.initials: W
authors.lastname: Niessen
authors.affiliation: Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus Medical Center, 3015 GE Rotterdam, The Netherlands.
authors.forename: Theo
authors.initials: T
authors.lastname: van Walsum
mesh_terms: D000465:Algorithms; D002908:Chronic Disease; D017023:Coronary Angiography / Q000379:methods*; D054059:Coronary Occlusion / Q000000981:diagnostic imaging / Q000601:surgery; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D004562:Electrocardiography / Q000379:methods; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008955:Models, Cardiovascular; D016011:Normal Distribution; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D012189:Retrospective Studies; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*