Advanced cardiac imaging

Advanced cardiac imaging describes techniques specifically designed to assess how well your heart is working. Combined with the results of other tests where necessary, this insight allows your cardiologist to assess your risk, confirm a diagnosis, and guide treatment recommendations.

Advanced cardiac imaging

CT coronary angiography (CTCA)

CTCA is an imaging technique used to evaluate the condition of the arteries supplying your heart muscle, known as the coronary arteries. CTCA is sometimes referred to as a cardiac CT scan or coronary CT angiogram. Compared to a conventional or invasive angiogram, the CTCA is less invasive and faster while still carrying high diagnostic value when used for the right patients.

How does CTCA work?

With the use of a contrast dye injected into a vein, a CT coronary angiography scan highlights the space through your coronary arteries and allows your cardiologist to see how well blood is flowing through these vessels. This can highlight any blockages, including soft and calcified plaque, revealing the location and extent of these obstructions. A cardiac CT angiogram can also show changes to the heart muscle, the valves, the membrane surrounding the heart (pericardium), and the chest.

CTCA is very useful in identifying individuals with coronary artery disease, and can also be used to check whether a coronary bypass graft is working as expected in select cases.

A CTCA is performed as a day procedure at a radiology practice and then interpreted and reported by our cardiac imaging subspecialist. 

It may be recommended if you have:

  • A strong family history of coronary artery disease
  • Symptoms that raise the suspicion of coronary artery disease, such as breathlessness, arrhythmia, or excessive sweating
  • Stable chest pain or acute chest pain
  • Been diagnosed with heart failure or cardiomyopathy

Though the duration of the actual scan is only about 20 minutes, your appointment can take around 2-3 hours in total. The best results are obtained with a low heart rate at the time of scanning. You are advised to not consume caffeine within 24 hours of the scan, and may be advised to take pre-medication like beta blockers to slow the heart.


Coronary artery calcium (CAC) scan

Also known as a calcium score test, a CAC scan is a non-invasive computed tomography (CT) scan performed without intravenous contrast, designed to evaluate the degree of calcified plaque in your arteries. This produces a coronary calcium score score, which indicates your risk of heart attack or cardiovascular disease over the next 10 years. A calcium score test has demonstrated value in predicting heart attack risk particularly in asymptomatic individuals at an intermediate risk of cardiovascular disease.

How does the calcium score test work?

Calcified plaque in the coronary arteries is a direct marker of atherosclerosis and the hardening of these blood vessels. A CAC score can fall anywhere from zero to over 400. The higher your CAC score, the more extensive the amount of plaque and the higher your risk of coronary artery disease.

The calcium score test is a type of cardiac CT. Unlike a CT coronary angiography, a calcium score test is entirely non-invasive and does not require the use of contrast dye. 

You may be recommended to undergo CAC scoring if you:

  • Are classed as intermediate risk of coronary heart disease, and have no symptoms
  • Are over the age of 40 years old
  • Have a family history of heart disease

The results of your CAC scan give your cardiologist more guidance in tailoring a treatment plan to you. This may involve reassurance that your risk is low and preventative medicine is not required, or that intervention is needed promptly to prevent a heart attack.


Invasive coronary angiogram (ICA)

A conventional, invasive coronary angiogram provides a visual of the blood flow through your heart’s blood vessels, and is used to identify areas of narrowing or blockage that may increase your risk of a cardiac event.

How does a coronary angiogram work? 

Where CTCA injects the contrast dye via an IV line, the invasive coronary angiogram requires a catheter to be inserted into your coronary artery. Access is generally gained via either the groin or the wrist, with local anaesthetic given. Although this type of coronary angiogram is more invasive and does come with greater risks compared to CTCA, it can provide a higher level of detail and may be more accurate in detecting problems in high-risk patients. Another significant advantage of a conventional coronary angiogram is that your cardiologist can treat the narrowing or obstruction of your arteries at the same time as detecting them, reducing your need for an additional procedure.

Invasive coronary angiography can be performed by one of our interventional cardiologists. You may be recommended an ICA if:

  • You have angina
  • You have valvular heart disease and are being considered for surgery
  • You have heart failure that might be caused by coronary artery disease
  • Your previous CTCA was inconclusive or indicated significant narrowing or blockage

Cardiac magnetic resonance imaging (MRI)

A cardiac MRI scan uses magnetic fields and radio waves to create images of your heart and associated blood vessels. It is a non-invasive imaging procedure, providing structural and functional details about your heart for the evaluation of many different cardiovascular conditions.

How does a cardiac MRI work?

There is no ionising radiation used in MRI, but due to the high-powered magnets in the machine, you must remove all metal objects from your person, such as watches and jewellery. If you have a pacemaker or other implanted device, an MRI may not be appropriate for you.

Contrast dye is injected intravenously during your scan, and you will also have an ECG recorded simultaneously. 

A cardiac MRI scan may be ordered and interpreted by our cardiac imaging subspecialist, and takes about 45 minutes to an hour to complete. A cardiac MRI scan may be recommended to investigate:

  • Pericarditis and myocarditis
  • Abnormal heart thickening (hypertrophy)
  • Cardiomyopathy
  • Scarring from a heart attack
  • Congenital heart disease
  • Arrhythmia
  • Family history of sudden cardiac death (SCD)

Frequently Asked Questions

An ICA is generally considered to be safe, though it does come with a low risk of complications due to its invasive nature and catheterisation of the coronary artery. Possible complications include pain or bruising at the site the catheter is inserted or allergy to the contrast dye. Serious complications occur in less than 2% of procedures, and may include heart attack or stroke.

Both CTCA and ICA have their advantages and disadvantages, and neither is inherently better than the other. CTCA is less invasive, comes with fewer complications, and may be the most appropriate for patients with low- to intermediate-risk of coronary artery disease. However, in higher risk patients or those who are expected to also need intervention to treat an artery blockage, an invasive coronary angiogram may be more suitable.

A coronary calcium score gives your cardiologist information about the degree of calcified plaque in your coronary arteries, which relates to your future heart disease risk. You may consider getting a coronary artery calcium scan if you have risk factors for heart disease such as hypertension, diabetes, high cholesterol, or a family history of premature heart disease. A coronary calcium score can be helpful in identifying whether preventative treatment will be beneficial for you or if it is safe to simply monitor.

Comprehensive cardiac care at Harbourside Cardiology, Sydney

At Harbourside Cardiology, our team is dedicated to providing holistic, patient-centred care that aligns with the most recent clinical guidelines and research. We are with you every step of your health journey, providing continuity of care of all heart conditions from initial assessment through to treatment and recovery.

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