If venous thrombosis is suspected, the following investigations are performed to confirm the diagnosis.



Duplex Ultrasound

This is a combination of ultrasound and Doppler (hence ‘duplex’) technology to assess the blood flow. The ultrasound waves travel through the tissue and back, enabling a computer to transform them into a moving image. Duplex ultrasound is the most popular method for diagnosing superfitial thrombophlebitis (STP) or deep vein thrombosis (DVT); it is painless, non-invasive and relatively easy to perform. At Phlebology Vascular Lab we use the latest duplex ultrasound systems following strict and detailed protocols to diagnose DVT.



Venography involves the injection of a dye into a large vein in the foot or ankle. An X-ray image is then taken to reveal the location of possible blood clots. Venography is one of the most accurate ways to identify deep vein thrombosis, but it may be uncomfortable. Occasionally it may cause phlebitis, an inflammation of the superficial veins. For these reasons,venography is no longer used routinely for DVT diagnosis.


Magnetic Resonance Imaging (MRI)

MRI uses a strong magnet to create a clear, high quality image of the body’s internal structures. It can be very effective in diagnosing DVT, especially in the thigh and pelvic areas. However, it is an expensive procedure and is only used in special circumstances.


Diagnosing Pulmonary Embolism

The symptoms of pulmonary embolism (PE) are not very specific, and can be present with many other conditions. Up to 75 per cent of patients suspected of having PE do not actually have this condition.

Special diagnostic tests, therefore, need to be performed. The three tests currently used to diagnose PE are pulmonary angiography, nuclear medicine lung scans and spiral CT scans.


Occasionally certain blood tests, such as D-dimer, are performed to confirm the diagnosis of DVT. Once the diagnosis is established, other blood tests, such as a thrombophilia screen, may be done to look for underlying tendencies to clotting. Certain other advanced tests such as Factor Xa Clotting Time (XACT), Rotational Thromboelastometry (ROTEM) and platelet function studies (MULTIPLATE) can be done in-house at the Phlebology Research Lab.