title: Visualization of coronary atherosclerotic plaques in patients using optical coherence tomography: comparison with intravascular ultrasound.
abstract: OBJECTIVE
  The aim of this study was to evaluate the feasibility and the ability of intravascular optical coherence tomography (OCT) to visualize the components of coronary plaques in living patients.
  
  
  BACKGROUND
  Disruption of a vulnerable coronary plaque with subsequent thrombosis is currently recognized as the primary mechanism for acute myocardial infarction. Although such plaques are considered to have a thin fibrous cap overlying a lipid pool, imaging modalities in current clinical practice do not have sufficient resolution to identify thin (< 65 microm) fibrous caps. Optical coherence tomography is a new imaging modality capable of obtaining cross-sectional images of coronary vessels at a resolution of approximately 10 microm.
  
  
  METHODS
  The OCT images and corresponding histology of 42 coronary plaques were compared to establish OCT criteria for different types of plaques. Atherosclerotic lesions with mild to moderate stenosis were identified on angiograms in 10 patients undergoing cardiac catheterization. Optical coherence tomography and intravascular ultrasound (IVUS) images of these sites were obtained in all patients without complication.
  
  
  RESULTS
  Comparison between OCT and histology demonstrated that lipid-rich plaques and fibrous plaques have distinct OCT characteristics. A total of 17 IVUS and OCT image pairs obtained from patients were compared. Axial resolution measured 13 +/- 3 microm with OCT and 98 +/- 19 microm with IVUS. All fibrous plaques, macrocalcifications and echolucent regions identified by IVUS were visualized in corresponding OCT images. Intimal hyperplasia and echolucent regions, which may correspond to lipid pools, were identified more frequently by OCT than by IVUS.
  
  
  CONCLUSIONS
  Intracoronary OCT appears to be feasible and safe. Optical coherence tomography identified most architectural features detected by IVUS and may provide additional detailed structural information.
authors.affiliation: Cardiology Division, Massachusetts General Hospital, Boston, Massachusetts 02114, USA. jang.ik@mgh.harvard.edu
authors.forename: Ik-Kyung
authors.initials: IK
authors.lastname: Jang
authors.forename: Brett E
authors.initials: BE
authors.lastname: Bouma
authors.forename: Dong-Heon
authors.initials: DH
authors.lastname: Kang
authors.forename: Seung-Jung
authors.initials: SJ
authors.lastname: Park
authors.forename: Seong-Wook
authors.initials: SW
authors.lastname: Park
authors.forename: Ki-Bae
authors.initials: KB
authors.lastname: Seung
authors.forename: Kyu-Bo
authors.initials: KB
authors.lastname: Choi
authors.forename: Milen
authors.initials: M
authors.lastname: Shishkov
authors.forename: Kelly
authors.initials: K
authors.lastname: Schlendorf
authors.forename: Eugene
authors.initials: E
authors.lastname: Pomerantsev
authors.forename: Stuart L
authors.initials: SL
authors.lastname: Houser
authors.forename: H Thomas
authors.initials: HT
authors.lastname: Aretz
authors.forename: Guillermo J
authors.initials: GJ
authors.lastname: Tearney
mesh_terms: D006328:Cardiac Catheterization; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000473:pathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055095:Optics and Photonics / Q000295:instrumentation*; D014054:Tomography / Q000295:instrumentation* / Q000379:methods*; D018084:Ultrasonography, Interventional