Doppler ultrasound is a non-invasive imaging test that uses high-frequency waves to estimate the amount of blood flowing via arteries and veins, those that supply blood to the arms and legs. Vascular flow studies also known as blood flow studies can monitor abnormal flow within an artery or blood vessels. This test helps to diagnose and treat several conditions including blood clots and poor circulation. A doppler ultrasound can be applied as part of a blood flow study. It is a pain-free procedure that needs minimal preparation. The results provide the doctor with information about blood flow and reveal any blocked or reduced blood flow in the arteries, which would ultimately lead to a stroke.
Why Doppler Ultrasound Is Performed?
The doctor may recommend an ultrasound if a person shows any signs of reduced blood flow in the arteries or veins of the legs, arms, or neck. Some of the conditions where the blood flow is reduced include:
Deep Vein Thrombosis (DVT) is a condition that develops when a blood clot is formed in one or more veins in the body (usually legs).
Superficial thrombophlebitis is an inflammation of the veins due to a clot in a vein beneath the skin’s surface.
Arteriosclerosis is a condition where the arteries that supply blood to the legs and feet are narrowed
Vascular tumours in arms or legs
This procedure also determines the blood pressure within arteries. It also shows how much blood is flowing via arteries and veins.
What Happens During A Doppler Ultrasound?
The test does not expose a person to harmful radiation and there are no risks associated with it and most people feel no discomfort. It is performed in the radiology department or peripheral vascular department of a hospital. The patient must remove clothing, any metal or jewellery and other objects from the area that has to be studied.
During the procedure, the person must lie down on an examination table and the doctor will place a water-soluble gel on a handheld device called a transducer, which sends high-frequency sound waves into arteries or veins. Blood pressure cuffs are placed around several regions of the body such as thigh, calf, ankle or different points along the arm and compare the blood pressure in different parts of the leg or arm.
Images are produced as the transducer is pressed against the skin and moved along the arm or leg. The transducer sends sound waves via the skin and other body tissues to the blood vessels. The sound waves echo off blood vessels and send the information to a computer to be processed and recorded. The computer produces graphs or pictures that show the flow of blood via the arteries and veins. The doctor will look for any narrowing of the blood’s vessels in the leg’s arteries and veins. This condition may lead to skin discolouration, pain when you walk or at rest and ulcers on the foot or ankle. It may take an hour to complete the test and based on person signs and symptoms they may be asked to do some mild exercises after the procedure.
After The Procedure
There are no specific instructions to be followed after a doppler ultrasound, the person may carry normal activities right away.
What To Expect?
Normal studies indicate that person has no blockages in the arteries and blood pressure is normal. Abnormal blood flow including narrowing or closing of the arteries can indicate:
Any blockage in the arteries due to build-up of cholesterol
Blood clots in a vein or artery
Poor circulation due to damaged blood vessels
Spastic arterial disease- a condition where the arteries contract due to stress or extreme climatic condition
Blockage in an artificial bypass graft
Some factors that may interfere with results and tests will need to be done again, these include:
Smoking less than 60 minutes before the test
Irregular heart rhythms
The test results will be sent to the doctor, if any abnormalities are found, then the doctor may suggest additional tests or treatment based on the patients need.