Vascular Ultrasound
Preparing for your DVT leg vein scan
Quick reference
Scan type
Ultrasound
Duration
20-30 minutes
Preparation
No special preparation usually required
Bring
Referral letter
What is a DVT ultrasound
A DVT (deep vein thrombosis) ultrasound - also called a venous duplex scan or lower limb venous ultrasound - uses sound waves and Doppler technology to assess blood flow in the veins of the leg. It can identify clots (thrombi) in the deep veins.
Why might it be requested
This scan may be requested when a patient has leg swelling, pain, redness or warmth that may suggest a deep vein thrombosis. It is also used to follow up a previously detected DVT.
How should I prepare
No special preparation is usually needed for a leg vein ultrasound. Avoid wearing tight clothing, compression bandages or tight socks on the legs if possible, as these can interfere with the scan. Follow the instructions given by your clinic.
What should I wear
Wear loose-fitting trousers or shorts that can be easily rolled up, or be prepared to wear a gown.
What happens during the scan
Gel is applied along the length of the leg veins. The sonographer moves a probe along the leg to assess the veins. You may be asked to take deep breaths or squeeze your calf muscle to help assess blood flow. You will hear a pulsed sound as blood flow is measured. The scan is performed with you lying on a couch.
Will it hurt
The scan should not be painful. The sonographer may apply gentle pressure with the probe over the vein.
How long does it take
Approximately 20 to 30 minutes.
When will I get results
Given that DVT scans are often clinically urgent, results may be available quickly and communicated to your referring clinician promptly. Ask your imaging centre or referring clinician about expected timescales.
When should I contact the clinic
If your symptoms worsen significantly - particularly if you develop chest pain, shortness of breath, you cough up blood, or you become very short of breath - seek emergency medical help (call 999) immediately rather than waiting for a scan. These could indicate a pulmonary embolism, which is a medical emergency.
Always follow your clinic specific instructions. The information here is general guidance only. Your clinic may have different requirements.