Comparison between automated and manual measurements of carotid intima-media thickness in clinical practice.
OBJECTIVE
The measurement of carotid intima-media thickness (cIMT) has been used as a marker of arterial wall disease. Manual measurements have been performed in most epidemiological studies, but, due to the introduction of new technologies, automated software has been increasingly used. This study aimed to compare manual versus automated cIMT measurements in common carotid (CC), bifurcation (BIF), and internal carotid (IC).


METHODS
Automated and manual cIMT measurements were performed online in 43 middle-aged females. Carotid segment measurements were compared by Bland-Altman plot and the variation and repeatability coefficients between observers were also determined for comparison.


RESULTS
The average timespan for manual measurements (57.30 s) were significantly higher than for automated measurements (2.52 s). There were no systematic errors between methods in any carotid segments. The variation coefficient was 5.54% to 6.34% for CC and BIF, 9.76% for IC, and absolute differences were 85% below 0.1 mm and 70% below 0.05 mm. Interobserver agreement showed no systematic error. The variation and the repeatability coefficients were better for the automated than manual measures.


CONCLUSIONS
Although both methods are reliable for cIMT measurements, the automated technique allows faster evaluation with lesser variability for all carotid segments currently used in atherosclerosis research.
Freire
Cláudia Maria Vilas
CM
Department of Internal Medicine, School of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil.
Ribeiro
Antonio Luiz Pinho
AL
Barbosa
Felipe Batista Lima
FB
Nogueira
Anelise Impelisiere
AI
de Almeida
Maria Cristina Costa
MC
Barbosa
Márcia Melo
MM
Lana
Angela Maria Quintão
AM
e Silva
Ana Cristina Simões
AC
Ribeiro-Oliveira
Antônio
A
D000328:Adult; D057205:Automation, Laboratory; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D017539:Tunica Intima / Q000648:ultrastructure*; D017540:Tunica Media / Q000000981:diagnostic imaging*; D014463:Ultrasonography