P1.07 Measurement of Carotid Intima-Media Thickness in Healthy Persons and Patients with Type 2 Diabetes - A Reproducibility Study

Abstract

Background

Carotid intima-media thickness (IMT) measured by B-mode ultrasound is a sensitive and non-invasive method for detection of subclinical cardiovascular disease (CVD) and is often used as primary outcome measure in clinical trials as a surrogate marker of CVD. The purpose of the present study was to quantify the repeatability of this method between and within sonographers and readers. Furthermore we studied the day-to-day variation.

Methods:

We used B-mode ultrasound and a computerized software programme (MIA vascular tools) for analysis of Carotid IMT (far wall of the common carotid artery). Measurement of Carotid IMT was done for 30 healthy persons and 28 T2D patients by two different sonographers and two different readers on two separate days.

Results:

Comparisons of Carotid IMT between readers assessing the same picture (reader variability) resulted in limits of agreement on the relative scale from 0.92 to 1.07, i.e. there is a 95% probability that the reading of a given picture by a second reader gives a thickness between 0.92 and 1.07 of the first reading. Comparing different sonographers resulted in limits of agreement from 0.83 to 1.22

We found no differences between healthy persons and patients with T2D.

Conclusion:

Measurement of carotid IMT has the same accuracy in both healthy persons and patients with T2D. The major sources of variation are the differences between sonographers and the day-to-day variation whereas the following reading of the recording using computerized software shows very little variation.