Renal Artery Stenosis Doppler Scan (RAS)


Renal artery stenosis Doppler ultrasound scan is a non-invasive diagnostic imaging technique used to assess blood flow in the renal arteries, which supply blood to the kidneys. The procedure involves the use of high-frequency sound waves (ultrasound) to create real-time images and detect the velocity of blood flow within the renal arteries.

The Doppler ultrasound technology allows the sonographer to analyse the blood flow patterns, including any areas of narrowing or stenosis in the renal arteries. Renal artery stenosis refers to the condition where there is a significant narrowing of one or both renal arteries, usually caused by the buildup of plaque or atherosclerosis.

During the Doppler ultrasound scan, the sonographer will examine the renal arteries for signs of stenosis, assess the velocity of blood flow, and check for any abnormalities or blockages. The test is typically considered safe, painless, and radiation-free.


• You should be fasting at least 6 hours before your ultrasound scan appointment. (Avoid drinking Tea, Coffee, Juice, Milk or Fizzy Drink Also avoid eating porridge) Still, water is Fine to drink.
• You must drink at least one liter of clear still water one hour before your appointment.
• Do not empty your bladder until after your scan.
• If you have diabetes, stick to your routine.
• If you are on any medication, please take your medicines as usual.