Digital Subtraction Angiography (DSA)

What is digital subtraction angiography (DSA)?

Digital subtraction angiography (DSA) is a diagnostic procedure to view the inner surface of blood vessels (also known as lumen). It can be used to view arteries, veins and heart chambers.

DSA is a fluoroscopic technique (a technique that captures continuous images) that uses complex, computerised X-ray machines. A special contrast medium or 'dye' is injected into your blood to make the blood vessels easier to see.

Images are taken before and after the contrast dye is injected. To highlight the blood vessels, software is used to digitally 'subtract' the first image from the second.

Why do you need digital subtraction angiography (DSA)?

DSA is used to diagnose:

• Abnormal connections between arteries and veins
• Blood vessel diseases, including obstructive vascular diseases that are caused by blocks or narrowing in the lumen (inside) of arteries and veins
• Brain aneurysms (especially intracranial aneurysms)
• Bleeding vessels

It may also be used to:

• Assess the blood vessel systems of cancerous tumours.
• Provide a visual guide for interventional procedures such as angioplasty (ballooning) and vessel stenting.

Who should not undergo digital subtraction angiography (DSA)?

This procedure may not be suitable if you:

• Have poor kidney functions
• Are hypersensitive to the iodinated contrast medium

What are the risks and complications of digital subtraction angiography (DSA)?

DSA is a relatively safe procedure. Complications are rare and may include:

• Allergy to the contrast medium
• Bleeding from the puncture site
• Harmful effects of the contrast medium on other organs (e.g. kidney)

How do you prepare for digital subtraction angiography (DSA)?

Before recommending DSA, your doctor will assess the following to decide if the procedure is suitable for you:

• Your medical history. Your doctor will look out for atherosclerotic diseases (e.g. heart attack or stroke), diabetes or poor kidney function.
• Medications you are currently taking.
• Allergies, if any.
• Previous surgeries, especially vascular ones.
• Previous reports of angiograms or vascular imaging studies relevant to the procedure.
• Any other health condition that could potentially cause complications.

What can you expect in digital subtraction angiography (DSA)?

DSA is done under local anaesthesia.

Estimated duration

The procedure takes about 30 minutes – 1 hour.

Before the procedure

You will be asked to lie down on the angiography table and given local anaesthesia.

During the procedure

During the procedure, your doctor will:

• Make a small incision in your leg
• Insert a catheter into the artery in the leg
• Inject a contrast medium, or dye, into the catheter to produce clear images of the blood vessels
• View the images on an X-ray machine to track the flow of the contrast medium through the artery

After the procedure

You will rest in a recovery area, where the medical team will observe you for any complications. During your recovery period, you should drink lots of water to flush out the contrast dye.