A comparative study on internal jugular vein valve insufficiency by colour Doppler ultrasound and contrastenhanced ultrasound

Abstract

Objective To explore the ultrasonographic characteristics of internal jugular vein(IJV) valve insufficiency and reflux.Methods 40 healthy volunteers' bilateral IJVs were study subjects.The inner diameter,valve morphological feature,reflux distance and hemodynamic parameters in IJV were detected by color Doppler ultrasound (CDU),the contrast agents transvalvular regurgitation in IJV was monitored by contrast-enhanced ultrasound (CEUS) (with low mechanical index,MI 0.10),then analyse the results of two methods.Results Of 80 investigated IJVs,1 vein was excluded due to absence of its left valve,so 79 veins were evaluated in the study.The IJV's inner diameter on the right side was larger than on the left side,but there was no significant difference (P ＞0.05).The detection rate of IJV valve insufficiency was 31.6％ (25/79),which was higher on the right than that on the left,but without significant difference (P ＞ 0.05).The detection rate of IJV valve insufficiency was significantly higher in the group of greater than or equal to 50 years old than that in less than 50 years old(P ＜0.05).The reflux distance in IJV displayed by CDU was associated with IJV valve's function.Compaired with sufficient valves,the reflux duration time in insufficient valves during quiet respiration showed no significant difference (P ＞0.05).During Valsalvalike manoeuvres and quiet respiration,the reflux duration time in sufficient valves showed no significant difference (P ＞ 0.05).The reflux duration time in insufficient valves during Valsalva-like manoeuvres showed significantly higher than that during quiet respiration (P ＜0.01).Compaired with sufficient valves,the peak flow velocity of reflux flow in insufficient valves was significantly prolonged during quiet respiration and Valsalva-like manoeuvres (P ＜0.05,P ＜0.01,respectively).Conclusions The incidence rate of IJV valve insufficiency and reflux is high in healthy individuals.During quiet respiration and/or Valsalva-like manoeuvres,detecting the reflux distance,reflux duration time and peak flow velocity of reflux flow by CDU are valuable in evaluating IJV valve insufficiency and the degree of IJV reflux. Key words: Ultrasonography ; Microbubbles; Jugular veins ; Valve insufficiency