How are DVT and PE diagnosed?

Legs on the beach

Find out what to expect when you are being diagnosed

D-dimer test for DVT diagnosis

This blood test detects the by-products of a blood clot and helps doctors identify if someone has DVT. It is possible for a D-dimer test to come back positive because it detects blood clot fragments from another injury, such as a cut or scrape. Therefore further tests are needed to fully verify a DVT diagnosis.

Ultrasound for DVT diagnosis

Most of us know ultrasound from pregnancy examinations but they are often used for other purposes like diagnosing DVT. This procedure is non-invasive; a health professional will move a hand-held device up and down your legs and watch the screen to see if a thrombus (blood clot) is evident.

Venogram for DVT diagnosis

If your doctor does not have a clear result after performing a D-dimer test and/or ultrasound, he or she may use a venogram test. In this procedure, a special dye will be injected into a vein in your foot and then an X-ray is used to take images of your leg. If you have DVT, the X-rays will show the dye gathered around the clot.

Computerised Tomography (CT) scan for PE diagnosis

A CT scan provides your doctors with a 2-dimensional image of your organs. To find out whether you have pulmonary embolism (PE), your doctor will inject a special dye into your blood. Images from the CT scan make it possible to see the blood vessels in your lungs, and identify if there is a clot.

Doctor preparing a woman for a CT check

Lung scan or Ventilation Perfusion Scan (V/Q scan) for PE diagnosis

A V/Q scan shows the flow of air through your lungs and in doing so will help your doctors identify if you have PE. With this procedure, you will inhale a special gas; the V/Q scan will then highlight how the gas flows through your lungs. At the same time, you will receive an injection that shows how blood is flowing through your lungs. Your doctor can identify PE when the scan shows that part of your lungs has air flowing through but not blood.


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