P128 RADIAL INTIMA-MEDIA THICKNESS ASSESSMENT BY ULTRA-HIGH FREQUENCY ULTRASOUND AND AUTOMATED IMAGE-ANALYSIS IN HEALTHY VOLUNTEERS

Abstract

Background: Ultrahigh-frequency ultrasound may represent a powerful tool for investigating the arterial properties of medium and small-size arteries. Aim of this study was: 1) to evaluate intra- and inter-operator reproducibility of radial artery vascular parameters (intima-media thickness –IMT- and diastolic diameter -DD), obtained both with a manual and an automatic approach; 2) to identify physiological correlates of radial IMT. Methods: 40 healthy subjects were examined by Vevo MD (FUJIFILM, VisualSonics, Toronto, Canada); in 11 volunteers two B-mode clips (longitudinal view) of the radial artery were acquired for each subject by two skilled operators. IMT DD were measured manually and using an automatic software (Cardiovascular Suite, QUIPU, Pisa, Italy). Coefficient of variations (CV) and Bland-Altman analysis were employed. Results: The manual approach provided intra-operator CV of 6.6% and 3.9% for DD and 6.5% and 6.6% for IMT (first and second operator). The automatic approach provided CV equal to 6.6%, 5.4%, 4.5% and 3%, respectively. Inter-operator CV were 11.3% for DD and 3.9% for IMT (manual), and 10.9% and 5.8% (automatic). Bland-Altman analysis provided non-significant bias for both IMT and DD measurements comparing manual and automatic approach. In the whole population, radial IMT was correlated with age (r = 0.35, p = 0.02) and pulse pressure (r = 0.41, p = 0.008), not with BMI (r = 0.05, p = 0.76) and mean blood pressure (r = 0.17, p = 0.28). No sex differences were observed. Conclusions: We obtained good CV values for both the intra- and inter-operator reproducibility; furthermore, the manual and the automatic approach provided similar results. Radial IMT increases with age and pulse pressure.