EVALUATION OF REPRODUCIBILITY OF A VESSEL WALL MOVEMENT DETECTOR SYSTEM FOR ASSESSMENT OF LARGE ARTERY PROPERTIES

Objective: Arterial distensibility (DC) and compliance (CC) are vessel wall properties of large arteries that can be measured non-invasively with a custom made vessel wall movement detector system (VWMDS). This study investigated the reproducibility of this device in 10 volunteer s. Methods: To investigate intraobserver intrasession and intraobserve r intersession variability, arterial diameter (D) and relative change in diameter during the heart cycle (Delta D/D) were measured in the el astic common carotid artery, and in the muscular femoral and brachial arteries. Interobserver intrasession variability was examined in commo n carotid artery by two observers, while interobserver variability on the same image was assessed for common carotid and femoral arteries. V ariability was expressed as the coefficient of variation. Results: For common carotid artery, intraobserver intrasession variability was 7.9 (SEM 1.6)% (Delta D/D), 4.5(1.1)% (D), 8.3(1.3)% (DC), and 9.1(2.6)% ( CC), respectively. In femoral artery it was 12.4(2.2)% (Delta D/D), 2. 7(0.6)% (D), 13.4(2.2)% (DC), and 12.5(2.1)% (CC). For brachial artery it was 13.4(2.8)% (Delta D/D), 2.5(0.5)% (D), 16.1(2.5)% (DC), and 15 .6(2.6)% (CC). Intraobserver intersession variability was comparable t o intraobserver intrasession variability for all vessels. Interobserve r intrasession variability for common carotid artery was 11.3(2.6)% (D elta D/D) and 8.6(1.9)% (D), but was larger for DC and CC. Interobserv er variability on the same image was <5% for common carotid and femora l arteries. Conclusions: In conclusion, the vessel wall movement detec tor system has a good technical reproducibility. Intraobserver intrase ssion and intersession variability are comparable, and are larger in m uscular arteries. This might be due to a larger variation in tone of t hese arteries, which are under permanent neurohumoral control. Interob server intrasession variability was larger than intraobserver variabil ity and might be influenced by differences in observers' skill and spo ntaneous variation in vessel wall properties.