title: In vivo validation of CAAS QCA-3D coronary reconstruction using fusion of angiography and intravascular ultrasound (ANGUS).
abstract: OBJECTIVE
  The CAAS QCA-3D system (Pie Medical Imaging BV, the Netherlands) was validated against 3D reconstructions based on fusion of angiography and intravascular ultrasound (ANGUS), allowing slice by slice validation of the lumen areas and 3D geometric values.
  
  
  BACKGROUND
  Accurate online 3D reconstruction of human coronary arteries is of outmost importance during clinical practice in the catheterization laboratory. The CAAS QCA-3D system provides technology to 3D reconstruct human coronary arteries based on two or more angiographic images, but was not validated in realistic arteries before.
  
  
  METHODS
  Ten patients were imaged using biplane angiography and an ECG gated (TomTec) intravascular ultrasound (IVUS) pullback (stepsize 0.5 mm, Boston Scientific). The coronary arteries were 3D reconstructed based on (a) fusion of biplane angiography and IVUS (ANGUS) and (b) CAAS QCA-3D using the biplane angiography images. For both systems the length, the curvature and the lumen areas at 0.5 mm spacing were calculated and compared.
  
  
  RESULTS
  Bland-Altman analysis indicated that the CAAS QCA-3D system underestimated the lumen areas systematically by 0.45 +/- 1.49 mm2. The segment length was slightly underestimated by the CAAS QCA-3D system (62.1 +/- 11.3 vs. 63.2 +/- 11.4 mm; P < 0.05), while the curvature of the analyzed segments were not statistically different.
  
  
  CONCLUSIONS
  The CAAS QCA-3D system allows 3D reconstruction of human coronary arteries based on biplane angiography. Validation against the ANGUS system showed that both the 3D geometry and lumen areas are highly correlated which makes the CAAS QCA-3D system a promising tool for applications in the catheterization laboratory and opens possibilities for computational fluid dynamics.
authors.affiliation: Biomedical Engineering, ErasmusMC, Rotterdam, The Netherlands.
authors.forename: Johan C H
authors.initials: JC
authors.lastname: Schuurbiers
authors.forename: Nieves Gonzalo
authors.initials: NG
authors.lastname: Lopez
authors.forename: Jurgen
authors.initials: J
authors.lastname: Ligthart
authors.forename: Frank J H
authors.initials: FJ
authors.lastname: Gijsen
authors.forename: Jouke
authors.initials: J
authors.lastname: Dijkstra
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
authors.forename: Antonius F
authors.initials: AF
authors.lastname: Van der Steen
authors.forename: Jolanda J
authors.initials: JJ
authors.lastname: Wentzel
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000628:therapy; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D015588:Observer Variation; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D018084:Ultrasonography, Interventional