Angiography
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Overview
Angiography is an imaging test that lets your doctor see the inside of your blood vessels — most commonly the arteries of the heart (coronary angiography), the brain (cerebral angiography), or the limbs (peripheral angiography).
It is used to look for blockages, narrowings, aneurysms, or abnormal connections.
There are two main types: conventional invasive angiography (using a thin tube called a catheter, with dye injected directly into the vessel of interest) and CT angiography (a special CT scan with dye injected through a vein in the arm). Your doctor will recommend the right one for your situation.
What is this test?
In invasive angiography, a thin catheter is inserted into an artery — usually in the wrist (radial) or groin (femoral) — and gently guided to the target vessel under live X-ray. Contrast dye is then injected, making the artery visible on screen.
CT angiography uses a high-speed CT scanner. Dye is injected through a vein in the arm, and the scanner times its images precisely so that the contrast is in the vessels of interest when the pictures are taken.
Why your doctor may order it
- Chest pain or suspected coronary artery disease
- Before angioplasty, stenting, or bypass surgery
- After abnormal stress test, ECG, or echocardiogram
- Suspected stroke or cerebral aneurysm
- Suspected blockage in the arteries of the legs (peripheral vascular disease)
- Investigation of unexplained kidney problems where renal artery disease is suspected
- Aortic aneurysm assessment and follow-up
How long does it take?
Coronary angiography (invasive) takes 30 to 45 minutes. With recovery and post-procedure observation, plan for 4 to 8 hours at the hospital. If a stent is placed in the same session, longer.
CT angiography is a 15 to 20 minute outpatient scan with minimal recovery time.
How to prepare
- Fast for 4 to 6 hours before the procedure.
- Tell us about all medications, especially blood thinners and diabetes medicines. Some may need to be paused.
- Tell us about any allergy to contrast dye or iodine, kidney problems, asthma, or thyroid disease.
- Inform us if you might be pregnant.
- For invasive angiography, you will usually be admitted as a day-case or for an overnight stay. Bring an overnight bag, your usual medications, and personal toiletries.
- Arrange someone to accompany you and drive you home.
- Bring previous angiograms, stress tests, and echocardiogram reports.
What to expect during the test
For CT angiography: you lie on a CT table. A cannula in your arm delivers contrast dye, and the scanner takes detailed pictures. You will be asked to hold your breath briefly. The scan itself is over in minutes.
For invasive angiography: you lie on a special X-ray table. The wrist or groin is cleaned and numbed with local anaesthetic. A small tube (sheath) is inserted into the artery, through which the catheter is advanced. You are awake but lightly sedated; you may feel pressure, but not sharp pain.
Contrast dye is injected; you may feel a warm flush or a metallic taste briefly. Multiple images are taken from different angles. The cardiologist or radiologist explains what they see, often during the procedure.
At the end, the catheter is removed and pressure is applied to the puncture site to stop bleeding, or a closure device is used. You will need to keep that arm or leg still for some hours afterwards.
After the test
- After CT angiography: drink plenty of water for the rest of the day. Resume normal activity immediately.
- After invasive angiography: you rest with the wrist or leg straight for 2 to 6 hours, depending on the access site. The puncture site is checked regularly. You may be allowed home the same day or kept overnight.
- Watch for warning signs and contact us immediately if you have: heavy bleeding from the puncture site, a new bulge or swelling, severe pain, weakness in the limb, chest pain, or breathing difficulty.
- Avoid heavy lifting and strenuous activity for 2 to 3 days after invasive angiography.
- Report is typically same day for invasive, and same or next day for CT angio.
Do's and Don'ts
- Fast as instructed.
- Tell us about all allergies — particularly to iodine or contrast.
- Drink plenty of water after the procedure to help your kidneys clear the dye.
- Keep the puncture site clean and dry for 24 hours.
- Call us straight away if you have heavy bleeding, severe pain, or breathing difficulty after the procedure.
- Don't continue blood thinners unless your doctor has confirmed it is safe.
- Don't drive yourself home after invasive angiography.
- Don't lift heavy weights or do strenuous activity for 2 to 3 days afterwards.
- Don't ignore a swelling, bruise, or pain at the puncture site that gets worse.
- Don't smoke for at least 24 hours after — and ideally, take this as a reason to stop altogether.
Understanding your results
The report describes the arteries examined and any blockages, narrowings, or other findings. Coronary angiography reports typically describe the major arteries (left main, LAD, circumflex, right coronary) and the percentage of any narrowing.
If a significant blockage is found, treatment options — medical therapy, angioplasty with stent, or bypass surgery — are discussed. Each option is explained, and the right one depends on the pattern of disease and your overall situation. A second opinion is reasonable before any major decision, and we support it.
Frequently asked questions
Mostly no. The puncture site is numbed and you feel pressure rather than pain. The contrast dye can cause a brief warm flush. Most people find the test more comfortable than they expected.
Serious complications are rare in experienced hands — under 1% in most centres for diagnostic angiography. We discuss the specific risks with you before the procedure. The benefit of a clear diagnosis usually outweighs the small risk.
Not always. Some patients with mild or moderate disease are managed with medication and lifestyle changes. Significant blockages causing symptoms may need angioplasty with stenting, sometimes in the same session. The decision is made based on the findings.
For many situations, yes — particularly to rule out coronary disease in patients with mild to moderate risk. For very severe disease or where treatment will probably be needed, invasive angiography is more useful because it allows the same-session treatment.
Both invasive and CT angiography involve X-rays. The dose is higher than a standard chest X-ray but justified by the diagnostic value. We use lower-dose protocols where possible.