Ultrasound radiofrequency-data technique assessment of carotid: a reproducibility study

Abstract

Objective To evaluate the reproducibility of quality intima-media thickness(QIMT) and quality arterial stiffness (QAS) technique in assessment of carotid under different measuring methods.Methods Between December 2012 and January 2014,carotid QIMT and QAS examinations were carried out in 30 health volunteers.QIMT and QAS indicators included IMT in QIMT and distensibility coefficient (DC),compliance coefficient(CC),stiffness index α(α),stiffness index β(β),pulse wave velocity(PWV) in QAS.The measurement employed unilateral/once,bilateral/twice,and unilateral/twice methods.Using intra observer and inter-observer variability,the reproducibility was compared between different QIMT and QAS indicators and measuring methods.Results Extremely high level of intra-observer reproducibility was found for both QIMT and QAS technique (ICC＞0.8).QIMT also showed an excellent inter observer reproducibility (ICC＞0.8).In contrast,the reproducibility of QAS technique varied in different indicators (PWV β ≈ α CC DC) and method ( ＞ bilateral/twice ＞ unilateral/twice).Conclusions QIMT measurement was highly reproducible.Whereas the reproducibility of QAS technique varied in different indicators and methods.Due to low reproducibility,the study result did not support the clinical application of DC indicator and unilateral/once method. Key words: Ultrasonography; Carotid arteries; Carotid intima-media thickness; Reproducibility of results