title: Clinical validation of an algorithm for rapid and accurate automated segmentation of intracoronary optical coherence tomography images.
abstract: OBJECTIVE
  The analysis of intracoronary optical coherence tomography (OCT) images is based on manual identification of the lumen contours and relevant structures. However, manual image segmentation is a cumbersome and time-consuming process, subject to significant intra- and inter-observer variability. This study aims to present and validate a fully-automated method for segmentation of intracoronary OCT images.
  
  
  METHODS
  We studied 20 coronary arteries (mean length=39.7±10.0 mm) from 20 patients who underwent a clinically-indicated cardiac catheterization. The OCT images (n=1812) were segmented manually, as well as with a fully-automated approach. A semi-automated variation of the fully-automated algorithm was also applied. Using certain lumen size and lumen shape characteristics, the fully- and semi-automated segmentation algorithms were validated over manual segmentation, which was considered as the gold standard.
  
  
  RESULTS
  Linear regression and Bland-Altman analysis demonstrated that both the fully-automated and semi-automated segmentation had a very high agreement with the manual segmentation, with the semi-automated approach being slightly more accurate than the fully-automated method. The fully-automated and semi-automated OCT segmentation reduced the analysis time by more than 97% and 86%, respectively, compared to manual segmentation.
  
  
  CONCLUSIONS
  In the current work we validated a fully-automated OCT segmentation algorithm, as well as a semi-automated variation of it in an extensive "real-life" dataset of OCT images. The study showed that our algorithm can perform rapid and reliable segmentation of OCT images.
authors: Cardiovascular Engineering and Atherosclerosis Laboratory, First Department of Cardiology, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece. Electronic address: joc@med.auth.gr.
authors: Yiannis S
authors: YS
authors: Chatzizisis
authors: Laboratory of Medical Informatics, Aristotle University Medical School, Thessaloniki, Greece.
authors: Vassilis G
authors: VG
authors: Koutkias
authors: First Department of Cardiology, Hippokration Hospital, Athens University Medical School, Athens, Greece.
authors: Konstantinos
authors: K
authors: Toutouzas
authors: Cardiovascular Engineering and Atherosclerosis Laboratory, First Department of Cardiology, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece.
authors: Andreas
authors: A
authors: Giannopoulos
authors: Laboratory of Medical Informatics, Aristotle University Medical School, Thessaloniki, Greece.
authors: Ioanna
authors: I
authors: Chouvarda
authors: First Department of Cardiology, Hippokration Hospital, Athens University Medical School, Athens, Greece.
authors: Maria
authors: M
authors: Riga
authors: Cardiovascular Engineering and Atherosclerosis Laboratory, First Department of Cardiology, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece.
authors: Antonios P
authors: AP
authors: Antoniadis
authors: Laboratory of Medical Informatics, Aristotle University Medical School, Thessaloniki, Greece.
authors: Grigorios
authors: G
authors: Cheimariotis
authors: Information Technologies Institute, Centre for Research and Technology Hellas, Thessaloniki, Greece.
authors: Charalampos
authors: C
authors: Doulaverakis
authors: Information Technologies Institute, Centre for Research and Technology Hellas, Thessaloniki, Greece.
authors: Ioannis
authors: I
authors: Tsampoulatidis
authors: Second Department of Cardiology, General Hospital of Nikaia, Piraeus, Greece.
authors: Konstantina
authors: K
authors: Bouki
authors: Information Technologies Institute, Centre for Research and Technology Hellas, Thessaloniki, Greece.
authors: Ioannis
authors: I
authors: Kompatsiaris
authors: First Department of Cardiology, Hippokration Hospital, Athens University Medical School, Athens, Greece.
authors: Christodoulos
authors: C
authors: Stefanadis
authors: Laboratory of Medical Informatics, Aristotle University Medical School, Thessaloniki, Greece.
authors: Nicos
authors: N
authors: Maglaveras
authors: Cardiovascular Engineering and Atherosclerosis Laboratory, First Department of Cardiology, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece.
authors: George D
authors: GD
authors: Giannoglou
mesh_terms: D000465:Algorithms; D006328:Cardiac Catheterization / Q000379:methods*; D003324:Coronary Artery Disease / Q000175:diagnosis*; D003331:Coronary Vessels / Q000473:pathology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D015203:Reproducibility of Results; D013997:Time Factors; D041623:Tomography, Optical Coherence / Q000379:methods*
keywords: Image processing; Image segmentation; Method comparison study; Optical coherence tomography