Does reproducibility software improve the inter- and intra-observer reproducibility of common carotid artery wall thickness measurement by B-mode imaging in human subjects?
The use of reproducibility software to reposition the ultrasound beam improves the intra- and inter-observer reproducibility of carotid intima-media thickness measurements.
METHODOLOGY: High-resolution B-mode imaging is a reliable, easily performed and non-invasive means of studying atherosclerosis in superficial blood vessels. Recently it has been used for in vivo studies on the thickness of the common carotid artery wall. It is very sensitive, although the results of practical investigations are highly dependent on both the operator and the direction and angle of ultrasound beams directed towards the vessel. PROTOCOL: We have assessed inter- and intra-observer reproducibility of the measurement of common carotid artery wall thickness in 13 subjects, using two procedures. The first was a standard echographical investigation. In the second procedure, the principal parameters recorded from the first investigation were used to reposition the beam with the same incident angle. RESULTS: Intra-observer variability (correlation coefficient, r = 0.61 for procedure 1 and r = 0.77 for procedure 2) and inter-observer variation (r = 0.58 for procedure 1 and r = 0.71 for procedure 2) were reduced when the second investigation was assisted by reproducibility software. CONCLUSIONS: The proposed method is a reliable and reproducible way of assessing combined intimal and medial wall thickness in the common carotid artery. It may be possible to improve reproducibility using specific software to aid the operator. Since the intimal and medial thickness of the common carotid artery appears to be a sensitive marker of vascular risk, the proposed standardized method of measuring these parameter may allow early detection and assessment of changes.
Touboul et al. (Wed,) studied this question.