title: Carotid intima-media thickness and hemodynamic parameters: reproducibility of manual measurements with Doppler ultrasound.
abstract: OBJECTIVE
  To evaluate the carotid ultrasound intra- and interobserver agreements in a common clinical scenario when making manual measurements of the intima-media thickness (IMT) and peak systolic (PSV) and end diastolic (EDV) velocities in the common (CCA) and the internal carotid (ICA) arteries.
  
  
  METHODS
  Three different experienced operators performed two time-point carotid ultrasounds in 21 patients with cardiovascular risk factors. Each operator measured freehand the CCA IMT three consecutive times in each examination. The CCA and ICA hemodynamic parameters were acquired just once. For our purpose we took the average (IMTmean) and maximum (IMTmax) IMT values. Quantitative variables were analyzed with the t-student, and ANOVA test. Agreements were evaluated with the Intraclass Correlation Coefficient (ICC).
  
  
  RESULTS
  IMTmean intraobserver agreement was better on the left (ICC: 0.930-0.851-0.916, operators 1-2-3) than on the right (ICC: 0.789-0.580-0.673, operators 1-2-3). IMTmax agreements (Left ICC: 0.821-0.723-0.853, operators 1-2-3; Right ICC: 0.669-0.421-0.480, operators 1-2-3) were lower and more variable. Interobserver agreements for IMTmean (ICC: 0.852-0.860; first-second ultrasound) and IMTmax (ICC: 0.859-0.835; first-second ultrasound) were excellent on the left, but fair-good and more variable on the right (IMTmean; ICC: 0.680-0.809; first-second ultrasound; IMTmax; 0.694-0.799; first-second ultrasound). Intraobserver agreements were fair-moderate for PSVs and good-excellent for EDVs. Interobserver agreements were good-excellent for both PSVs and EDVs. Overall, 95% confidence intervals were narrower for the left IMTmean and CCA velocities.
  
  
  CONCLUSIONS
  Intra and interobserver agreements in carotid ultrasound are variable. In order to improve carotid IMT agreements, IMTmean is preferable over IMTmax.
authors.affiliation: Radiology Department. University General Hospital Morales Meseguer. Murcia, Spain. plasen79@gmail.com.
authors.forename: Juana M
authors.initials: JM
authors.lastname: Plasencia Martínez
authors.affiliation: Radiology Department. University General Hospital Morales Meseguer. Murcia, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Garcia Santos
authors.affiliation: Radiology Department. University General Hospital Morales Meseguer. Murcia, Spain.
authors.forename: Maria L
authors.initials: ML
authors.lastname: Paredes Martinez
authors.affiliation: Radiology Department. University General Hospital Morales Meseguer. Murcia, Spain.
authors.forename: Ana Moreno
authors.initials: AM
authors.lastname: Pastor
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002318:Cardiovascular Diseases / Q000000981:diagnostic imaging*; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging*; D059168:Carotid Intima-Media Thickness / Q000706:statistics & numerical data*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012307:Risk Factors; D018616:Ultrasonography, Doppler, Duplex