title: Variability in the measurement of intracoronary ultrasound images: implications for the identification of atherosclerotic plaque regression.
abstract: OBJECTIVE
  Serial coronary angiography cannot reliably detect the small changes in arterial dimensions. Measurement of arterial dimensions by intracoronary ultrasound (ICUS) may be a superior method to determine the extent of atherosclerotic burden since it directly images the diseased portion of the vessel.
  
  
  METHODS
  To quantify inter- and intraobserver variability of ICUS measurements, 27 images of atherosclerotic coronary lesions were measured by two study physicians and repeated 14 days later.
  
  
  RESULTS
  Interobserver correlation coefficients for external elastic lamina, lumen, and effective plaque area were 0.96, 0.99, and 0.91, respectively. Intraobserver correlation coefficients for external elastic lamina, lumen, and effective plaque area were 0.99, 0.99, and 0.97, respectively. To determine progression or regression in effective plaque area, a minimal difference of 2.77 mm2 (which represents a 23% change in plaque area) is needed.
  
  
  CONCLUSIONS
  Direct visualization of the extent of atherosclerosis by ICUS can be accomplished with a low degree of inter- and intraobserver variability. ICUS may be a preferable alternative to angiography in atherosclerosis regression trials.
authors.affiliation: Institute for Prevention of Cardiovascular Disease, Deaconess Hospital, Bridgeport, Connecticut, USA.
authors.forename: G P
authors.initials: GP
authors.lastname: Foster
authors.forename: M A
authors.initials: MA
authors.lastname: Mittleman
authors.forename: M
authors.initials: M
authors.lastname: Koch
authors.forename: G
authors.initials: G
authors.lastname: Abela
authors.forename: S W
authors.initials: SW
authors.lastname: Zarich
mesh_terms: D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D015588:Observer Variation; D015203:Reproducibility of Results; D018084:Ultrasonography, Interventional