Venous Thrombus Investigation With Contrast Enhanced Ultrasound Imaging

Background:

During the repair process of deep venous thrombosis, capillary formation is seen from day 18 to day 25. Contrast agent investigation is well known to detect small vessels in arterial disease. We intend to use this method to detect early vascularisation in the thrombus, in order to get more information about the evolution of the thrombosis in vivo.

Aims of the study:

Investigation of a newly diagnosed occluding venous thrombus with duplexsonography, using contrast agent and compare the degree of vascularization in the same patient after 3 weeks and 3 months. The relative signal intensity difference (baseline to peak) of the time intensity curve (TIC) is measured in defined region of interests (ROI). Comparison of the visibility of revascularisation between color duplexsonography, power mode and contrast agent will be done.

Method:

Patients with venous thrombosis of the proximal limb veins (femoral or popliteal vein) will be investigated with ultrasound agent in supine position. 5 ml of the contrast agent sulfur hexafluoride is given intravenously into a vein of the dorsal foot. The measurements are done in a defined area, where the thrombus is fully occluding in color Doppler investigation. The regions of interest will be the vessel walls and the centre of the thrombus in cross section view. The signal intensities are measured at baseline and peak (in decibel) in the centre and in the peripheral part of the vein. 20 patients with acute deep venous thrombosis will be included in this pilot study and investigated at baseline, after 3 weeks and 3 months.

Previously (before contrast agent application), the veins are investigated with color - and power Doppler to test visibility in comparison to the contrast agent investigation.