title: Multi-examiner reliability of automated radio frequency-based ultrasound measurements of common carotid intima-media thickness in rheumatoid arthritis.
abstract: OBJECTIVE
  To assess the reliability of the automated radio frequency (RF)-based US measurement of carotid intima-media thickness (IMT) performed by rheumatologists and to evaluate the variability between this method and the conventional B-mode US measurement of carotid IMT in RA patients.
  
  
  METHODS
  Twelve rheumatologists measured in two blinded rounds the IMT of both common carotid arteries (CCAs) of seven RA patients with an automated RF-based method. At each round, a cardiologist measured both CCA-IMTs of the patients using an automated B-mode method. Inter-observer reliability for RF-based IMT measurements was evaluated by the intra-class correlation coefficient (ICC). Intra-observer reliability for RF-based IMT measurements was assessed using the root mean square coefficient of variation (RMS-CV), Bland-Altman method and ICC. Agreement between the two US methods was evaluated by the Bland-Altman method, ICC and RMS-CV.
  
  
  RESULTS
  Inter-observer ICCs for the RF-based CCA-IMT measurements were 0.85 (95% CI 0.69, 0.94) for the first round, and 0.77 (95% CI 0.55, 0.91) for the second round. RMS-CVs for the RF-based CCA-IMT measurements varied from 5.6 to 11.7%. The mean intra-observer ICC for the RF-based CCA-IMT measurements was 0.61 (95% CI 0.46, 0.71). In the Bland-Altman analysis for agreement between RF-based and B-mode CCA-IMT measurements, the mean difference varied from -0.6 to -19.7 μm. Inter-method ICCs varied from 0.57 to 0.83 for 11 rheumatologists. Inter-method RMS-CVs varied from 11.3 to 13.7%.
  
  
  CONCLUSIONS
  Our results suggest that automated RF-based CCA-IMT measurement performed by rheumatologists can be a reliable method for assessing cardiovascular risk in RA patients.
authors: Department of Rheumatology, Hospital Universitario Severo Ochoa, Madrid, Spain. enaredo@ser.es
authors: Esperanza
authors: E
authors: Naredo
authors: Ingrid
authors: I
authors: Möller
authors: Marwin
authors: M
authors: Gutiérrez
authors: David A
authors: DA
authors: Bong
authors: Tatiana
authors: T
authors: Cobo
authors: Hector
authors: H
authors: Corominas
authors: Alfonso
authors: A
authors: Corrales
authors: Luca
authors: L
authors: Di Geso
authors: Maria Luz
authors: ML
authors: Garcia-Vivar
authors: Annamaria
authors: A
authors: Iagnocco
authors: Pilar
authors: P
authors: Macarrón
authors: Teresa
authors: T
authors: Navio
authors: Jesús
authors: J
authors: Garrido
authors: Carlos
authors: C
authors: González-Juanatey
mesh_terms: D001172:Arthritis, Rheumatoid / Q000150:complications / Q000000981:diagnostic imaging*; D050197:Atherosclerosis / Q000150:complications / Q000000981:diagnostic imaging*; D001331:Automation; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011846:Radio Waves; D015203:Reproducibility of Results; D012984:Software; D017539:Tunica Intima / Q000000981:diagnostic imaging*; D017540:Tunica Media / Q000000981:diagnostic imaging*; D014463:Ultrasonography / Q000379:methods*