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The overlay of color onto the Doppler information lets these images be seen more clearly. [8] The choice of a probe will depend on the depth needed to be studied. For example, the superficial venous system (SVS) can be very well examined using a high-frequency probe of 12 MHz.
Unlike arterial ultrasonography, venous ultrasonography is carried out with the probe in a transversal position, (perpendicular to the vein axis), displaying cross-sections of the veins. [4] All collateral veins are better detected this way, including perforator veins, but of most importance is the detection of venous thrombosis.
Absence of the portal system in a first trimester case associated with hygroma and aorto-umbilical fistula. (A): Transverse plane of the upper abdomen with color Doppler applied, showing umbilical cord insertion, stomach, the prominent hepatic artery and no afferent liver venous perfusion; (B): midsagittal plane reconstructed from a three-dimensional volume acquisition were the crown-rump ...
Medical ultrasound includes diagnostic techniques (mainly imaging techniques) using ultrasound, as well as therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal body structures such as tendons, muscles, joints, blood vessels, and internal organs, to measure some characteristics (e.g., distances and velocities) or to generate an informative audible sound.
A lower limbs venous ultrasonography may refer to: Ultrasonography of chronic insufficiency of the legs; Ultrasonography of deep venous thrombosis
The most common cause of chronic venous insufficiency is reflux of the venous valves of superficial veins. [2] This may in turn be caused by several conditions: Deep vein thrombosis (DVT), that is, blood clots in the deep veins. Chronic venous insufficiency caused by DVT may be described as postthrombotic syndrome. DVT triggers an inflammatory ...
Lower limb venography is indicated in deep vein thrombosis, oedema with unknown cause, and congenital abnormality of the venous system. Less frequently it is used to demonstrate the incompetent valves of perforating veins. Doppler ultrasound is preferable rather than venography to access the competence of the veins.
Laser Doppler imaging (LDI) is an imaging method that uses a laser beam to image live tissue. When the laser light reaches the tissue, the moving blood cells generate Doppler components in the reflected (backscattered) light. The light that comes back is detected using a photodiode that converts it into an electrical signal.