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The Sydney Vascular Laboratory provides a full range of noninvasive diagnostic ultrasound testing for assessment of the arterial and venous systems of the neck, chest, abdomen, upper and lower extremities. Physiologic non-imaging examinations are also used to provide necessary diagnostic information.
Please refer to our Request Form for a full list of the diagnostic tests available at
Sydney Vascular Laboratory.
FAQ's
What is ultrasound?
What happens in an ultrasound examination?
Why do we do these tests?
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What is Ultrasound?
An ultrasound is a procedure that uses high frequency sound waves to produce images of structures within the body.
Ultrasound uses the principles of sonar which was initially developed to track submarines during World War 1.
The examination is performed by an individual who specializes in ultrasound imaging (sonographer). At SVL we use state of the art ultrasound equipment called a Duplex Scanner and only have specialist vascular and cardiac sonographer's performing these tests.
Doppler ultrasound measures the direction and speed of blood cells as they move through vessels, including the body’s major arteries and veins in the neck, limbs and abdomen. The sounds are processed through the computer and displayed as graphs that represent flow of blood through these vessels. These images assist with the diagnosis of blockages to blood flow and narrowing of vessels.
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The Duplex Scanner is an ultrasound machine combining real-time imaging and Doppler capabilities in the one unit. This enables the sonographer to image the blood vessel and listen to its flow.
The diagram to the left demonstrates the 2 dimensional image with flow in the vessel shown in colour. The graph on the bottom is called a spectral image and signifies the velocity of the red blood cells flowing within the center of the vessel.
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What happens in an ultrasound examination?
During the examination coupling gel is applied to your skin which eliminates pockets of air forming between the skin and the hand-held device (transducer) which generates and receives the sound waves. Air impedes the ultrasound transmission. The sonographer presses the transducer over the areas of the body being examined and the procedure is usually painless. Sometimes a significant amount of pressure may be required if there is a large amount of tissue for the sound waves to travel through. This pressure may cause mild discomfort.
Crystals within the transducer emit pulses of sound waves that travel through your body. These high frequency sound waves are inaudible to the human ear. The sound waves bounce off the internal organs, fluids and tissues back to the transducer. This information is then sent to a computer which processes the information and creates a detailed image on the screen.
These images are reviewed and a detailed report of the findings is sent to your referring doctor. A provisional report is available on completion of the examination.
A typical ultrasound will take from 30 minutes to an hour depending on the type of examination required. Most ultrasounds require no preparation. Ultrasounds on the abdomen require you to fast for 12 hours prior to the procedure. You will be provided with any necessary instructions when your ultrasound appointment is made.
Diagnostic ultrasound is a safe procedure with no known harmful effects.
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Why do we do these tests?
Firstly ultrasound is non-invasive and painless. Secondly depending on the area imaged it provides the investigator with the information needed to make informed decisions in the treatment of your condition.
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In particular, investigation for cerebrovascular disease assesses blockages (occlusions) and narrowings (stenoses) in the arteries that supply blood to the brain (carotid arteries). Disease in these vessels can increase the risk of Stroke.
The image on the right demonstrates the internal jugular vein on top of the carotid artery bifurcation. Of particular note, the ulcerated plaque can be seen at the bifurcation causing severe narrowing of the vessel and the cause of a stroke in this patient. |
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When assessing the leg and arm arteries (peripheral arterial disease) we are looking for stenoses and occlusions that can cause claudication, rest pain, ulcers and gangrene.
The venous system has two major reasons for performing an ultrasound, venous thrombosis and venous incompetence. Blood clots in the veins can have the potential to dislodge and travel to the lungs and venous incompetence can cause varicose veins and eventually venous ulcers.
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This image identifies the common femoral vein and the saphenofemoral junction. This is where the long saphenous vein joins the common femoral vein in the groin and is a common place for venous incompetence.
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This image demonstrates the blood flowing backwards into the long saphenous vein at the saphenofemoral junction. If there is back flow of greater than 0.5 seconds, the vein is considered incompetent at that level.
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Ultrasound can diagnose enlargement of blood vessels called aneurysms. These can occur anywhere in the vascular tree and when they increase to large sizes can rupture and cause death. Typical examples are abdominal aortic aneurysms, popliteal artery aneurysms, renal artery aneurysms, carotid artery aneurysms as well as others.
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An image of an abdominal aortic aneurysm after it has been treated successfully with an endoluminal stent-graft.
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This ultrasound image demonstrates the successful treatment of a common iliac artery aneurysm that has been stent-grafted.
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Renal artery disease can lead to disorders that cause high blood pressure and kidney failure. These can be diagnosed relatively easily with the use of duplex ultrasound.
Stenoses and occlusions of the arteries of the intestines is referred to as mesenteric artery disease. This can be the cause of abdominal pain, especially when it has a relationship to food ingestion and can lead to severe weight loss.
Echocardiography is the ultrasound assessment of the heart and this can be done through the chest wall (trans-thoracic) or by internal means (trans-oesophageal). This is able to detect problems in the structure and function of the heart as well as possible clot with in the heart that can cause strokes and emboli to all parts of the body.
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