Analysis of internal jugular vein insufficiency--a comparison of two ultrasound methods.

Jugular venous valve insufficiency is a contributing factor to different pathologic conditions. For assessment of insufficiency, two ultrasound techniques have been developed, that are based on very different methodology (direct Doppler assessment versus air contrast ultrasound venography [ACUV]). This study was conducted to compare these two methods to improve comparability of existing studies and diagnostic accuracy in future studies. The function of 40 valves was determined in 20 individuals during a Valsalva maneuver. For direct Doppler assessment, valvular competence was assessed on basis of Doppler recordings, following recently established criteria. Valvular insufficiency in ACUV was diagnosed when reflux of an air-based echo contrast agent through the valve could be detected. With both methods, evaluation of 39 valves was accomplished (one exclusion due to hypoplasia of the corresponding vein). Both methods showed very high agreement in detection rates. All 18 valves being classified as insufficient by Doppler criteria were also insufficient in ACUV. Of 21 valves classified as competent (Doppler), one valve was rated as insufficient in ACUV due to discrete reflux of microbubbles. However, ACUV was inaccurate in evaluation of the left internal jugular vein after injection of the contrast agent into the right cubital vein. High detection rates could only be achieved when this was taken into account. This study shows that detection rates of internal jugular valve insufficiency are very similar with both methods. However, this high agreement required modification of the established protocol of ACUV.