Doppler ultrasound

What is a Doppler ultrasound?

A Doppler ultrasound is a non-invasive imaging test that uses high-frequency sound waves to produce images of blood moving through blood vessels. The images can highlight the direction and speed that blood flows through your arteries, veins and heart.  

A Doppler ultrasound can be a beneficial investigative test if doctors suspect you may have a disorder affecting your blood vessels, such as aneurysms, carotid artery disease, poor leg circulation, varicose veins, or deep vein thrombosis. It can also help to check your blood flow, particularly if you’ve had major surgery or are undergoing specific treatments.  

At Royal Brompton and Harefield hospitals, our vascular surgeons are pioneers in minimally invasive procedures for vascular diseases (blood vessel disorders). They can provide a fast and accurate diagnosis for a range of vascular conditions, as well as the most effective treatment.

What does a Doppler ultrasound show?

A Doppler ultrasound is a safe, painless scan that uses sound waves to show how blood is flowing through your blood vessels. We can use it to diagnose many different health conditions, such as:  

• narrowed arteries or veins 
• varicose veins 
• carotid artery disease 
• blood clots 
• valvular heart disease 
• deep vein thrombosis (DVT) – where a blood clot forms in a deep vein, typically in your leg, arm or pelvis 
• heart valve defect 
• congenital heart disease 
• poorly functioning heart valves 
• poor circulation in your legs

It can also be used to evaluate the blood supply to a transplanted organ, like a kidney or liver.

Types of Doppler ultrasound we offer

There are several types of Doppler ultrasound that our consultants may recommend, including: 

• colour Doppler – uses a special computer to convert sound waves into colours, showing the speed and direction of blood flow
• spectral Doppler – shows a graphical representation of blood flow
• duplex Doppler – combines a traditional ultrasound with a Doppler ultrasound
• carotid Doppler – detects possible blockages in the carotid arteries on either side of your neck supplying blood to the brain
• power Doppler – shows slow blood flow, not direction, and is most commonly used to reveal blood flow inside organs
• transcranial Doppler – examines blood flow in the brain to detect strokes or haemorrhages

If you’re unsure which doppler ultrasound is right for you, contact our team to arrange an appointment and a specialist will discuss them with you.

We’ll confirm which Doppler is ideal for you during your consultation so you can know what to expect at your appointment. 

If you are concerned about vascular disease, our consultants are here to help. Contact our team to arrange an appointment at a time that suits you. 

How to prepare for a Doppler ultrasound 

Before your Doppler ultrasound, we may advise you to fast (stop eating and drinking) a certain number of hours before your test.  

We might also ask you to quit smoking or avoid nicotine products for at least 2 hours beforehand. Nicotine narrows your blood vessels, which may lead to inaccurate results.  

We’ll explain any specific preparations you must make before your Doppler ultrasound so you can confidently arrive at your appointment.

How is a Doppler ultrasound performed?

Our expert sonographers perform a Doppler ultrasound by placing an ultrasound probe over specific body areas. They’ll apply some gel to your skin to help the probe glide smoothly and enhance the sound waves to travel.  

The sound waves that the probe emits enter your body and return to the probe. A special computer translates the echoes into images showing the direction and speed of your blood flow.  

Sometimes, you must wear a blood pressure cuff while we perform the test. The sonographer will inflate the cuff to record your blood pressure and slowly let it down again as the probe detects blood flow.  

Your sonographer will explain the process before your Doppler ultrasound so you know what to expect.

If you would like to speak to one of our consultant about the Doppler ultrasound in more detail and discuss which option is right for you, contact us to book an appointment. 

How long does a Doppler ultrasound take?

A Doppler ultrasound scan can take up to 60 minutes, but on average, they usually take 30 minutes. You can expect to go home soon after your scan, as no hospital stay is required.

Are there any side effects with a Doppler ultrasound?

A Doppler ultrasound has no side effects because the test is non-invasive and the sound waves are not harmful or painful. It also uses no radiation either. 

Doppler ultrasounds are safe for pregnant women too, and are not too dissimilar to a standard pregnancy scan.  

Results

Your results won’t be ready immediately because our consultant must assess them. It can take up to 1 week for your results to be prepared.  

Depending on your results, you may need to return to the hospital to talk them through. We’ll also discuss a personalised treatment plan based on your results at your follow-up appointment.