title: Fully automatic three-dimensional quantitative analysis of intracoronary optical coherence tomography: method and Validation.
abstract: OBJECTIVE
  Quantitative analysis of intracoronary optical coherence tomography (OCT) image data (QOCT) is currently performed by a time-consuming manual contour tracing process in individual OCT images acquired during a pullback procedure (frame-based method). To get an efficient quantitative analysis process, we developed a fully automatic three-dimensional (3D) lumen contour detection method and evaluated the results against those derived by expert human observers.
  
  
  METHODS
  The method was developed using Matlab (The Mathworks, Natick, MA). It incorporates a graphical user interface for contour display and, in the selected cases where this might be necessary, editing. OCT image data of 20 randomly selected patients, acquired with a commercially available system (Lightlab imaging, Westford, MA), were pulled from our OCT database for validation.
  
  
  RESULTS
  A total of 4,137 OCT images were analyzed. There was no statistically significant difference in mean lumen areas between the two methods (5.03 + or - 2.16 vs. 5.02 + or - 2.21 mm(2); P = 0.6, human vs. automated). Regression analysis showed a good correlation with an r value of 0.99. The method requires an average 2-5 sec calculation time per OCT image. In 3% of the detected contours an observer correction was necessary.
  
  
  CONCLUSIONS
  Fully automatic lumen contour detection in OCT images is feasible with only a select few contours showing an artifact (3%) that can be easily corrected. This QOCT method may be a valuable tool for future coronary imaging studies incorporating OCT.
authors.affiliation: Thoraxcenter, Delft, The Netherlands.
authors.forename: Kenji
authors.initials: K
authors.lastname: Sihan
authors.forename: Charl
authors.initials: C
authors.lastname: Botha
authors.forename: Frits
authors.initials: F
authors.lastname: Post
authors.forename: Sebastiaan
authors.initials: S
authors.lastname: de Winter
authors.forename: Nieves
authors.initials: N
authors.lastname: Gonzalo
authors.forename: Evelyn
authors.initials: E
authors.lastname: Regar
authors.forename: Patrick J W C
authors.initials: PJ
authors.lastname: Serruys
authors.forename: Ronald
authors.initials: R
authors.lastname: Hamers
authors.forename: Nico
authors.initials: N
authors.lastname: Bruining
mesh_terms: D016477:Artifacts; D001331:Automation; D003324:Coronary Artery Disease / Q000175:diagnosis*; D005240:Feasibility Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D015588:Observer Variation; D011237:Predictive Value of Tests; D012044:Regression Analysis; D015203:Reproducibility of Results; D013997:Time Factors; D041623:Tomography, Optical Coherence / Q000379:methods*