Is manual ultrasonographic measurement of carotid intima-media thickness a reproducible cardiovascular biomarker?

To establish the ability of a potential biomarker to discriminate between diseased and healthy subjects, it is essential to know the intrinsic variability of the methods used to measure the biomarker. This aspect is especially important in the ultrasonographic measurement of carotid intima-media thickness, where submillimetric variations due largely to the unrecognized lack of precision in the ultrasonographic technique can have a significant clinical impact on the classification of cardiovascular risk. This article aims to present the evidence about the reproducibility of carotid intima-media thickness measured by ultrasonography to discuss whether the variability inherent in the technique can influence the potential of this parameter as a biomarker.