Ultrasound assessment of atherosclerotic vessel wall changes - Reproducibility of intima-media thickness measurements in carotid and femoral arteries

RATIONALE AND OBJECTIVES. Ultrasonography is widely used in cardiovascular research to quantify early atherosclerotic vessel wall changes. In this art icle, we examined the short- and long-term reproducibility of this techniqu e in the common carotid artery, carotid bifurcation, common femoral artery, and superficial femoral artery. Furthermore, we assessed the effect of pro gressed atherosclerosis on reproducibility. METHODS. Repeated ultrasound examinations were performed by one observer on 15 healthy individuals and 18 patients suffering from coronary heart disea se. Intima-media thickness was determined by B-mode ultrasonography. The ex aminations were repeated by the same observer after a short time interval ( short-term) and after a few weeks (long-term) and expressed as the mean dif ference between the measurements and the coefficient of variation (CV). RESULTS. The reproducibility of the intima-media thickness determination tu rned out to be best in the common carotid artery and the superficial femora l artery when performed in healthy controls (CV 5.6% and 5.5%, respectively ). Reproducibility was less in patients with clinical atherosclerosis; this especially affected the reliability of the superficial femoral artery meas urement (CV in healthy controls was 5.5%; in coronary heart disease patient s, 17.5%). The reliability of the intima-media thickness measurements in th e common carotid artery (CV in healthy controls was 5.6%; in coronary heart disease patients, 9.5%) proved to be least affected by progressed atherosc lerosis. A longer time interval between measurements did not affect the rep roducibility of intima-media thickness measurements in healthy controls, wh ereas in the patients it led to some decrease of reproducibility and to a m ajor decrease in reproducibility of the superficial femoral artery measurem ents (CV changed from 12.7% to 17.5%). CONCLUSIONS. Ultrasonography is a reliable and accurate technique to determ ine intima-media thickness in superficial arteries, In studies in which the intima-media thickness determination is used as a marker for generalized a nd coronary atherosclerosis, the common carotid artery should always be inc luded, whereas the benefit of inclusion of other arteries depends on age an d the expected extent of atherosclerosis in the individuals studied.