Cardiac Imaging

A Myocardial Perfusion Scan images the blood supply (perfusion) to the heart muscle using a gamma camera. The blood supply is made visible to the camera by the introduction of a small amount of radioactive tracer (radiopharmaceutical or MIBI) injected into an arm vein.  Occasionally an alternative tracer called Thallium is used. Depending on the exact heart condition in question, the procedure may be performed at rest, with the heart under stress or, most commonly, both. There are two types of myocardial perfusion, Exercise and Pharmaceutical.

Myocardial scans give information useful in diagnosing and managing conditions such as coronary artery disease, dead tissue resulting from a lack of blood supply (infarcts) and diseases of the heart muscle (cardiomyopathy).

EXERCISE
An Exercise Stress Myocardial Perfusion Scan examines the blood supply (perfusion) to the heart muscle using a gamma camera.  The blood supply is made visible to the camera by the introduction of a small amount of radioactive tracer, (radiopharmaceutical or MIBI) injected into an arm vein.  The injection is given during stress exercise on a treadmill, then again while resting later on. 

PHARMACEUTICAL
A Pharmaceutical Stress Myocardial Perfusion Scan examines the blood supply (perfusion) to the heart muscle using a gamma camera.  The blood supply is made visible to the camera by the introduction of a small amount of radioactive tracer, (radiopharmaceutical or MIBI) injected into an arm vein.  The injection is given during stress, then again while resting later on. The heart is subjected to a stress test using a pharmaceutical called persantin, as an alternative to exercising. 

You will need to bring:

• Your referral form
• Any relevant previous imaging
• Your Medicare card and any concession cards
• All of your current medications in their containers

A referral from your doctor or medical specialist, and an appointment is required for this examination.

Before you attend your appointment, please read and follow the printed instructions exactly.

During the 24 hours before your appointment time:

• DO NOT drink any tea, coffee, chocolate or cola drinks (even small amounts).
• DO NOT eat anything containing caffeine (even small amounts).
• DO NOT eat chocolate.
• DO eat a light breakfast on the day of your appointment.
• DO ADVISE us before the appointment if you are diabetic and follow the printed instructions for diabetics.
• CHECK the list of medications which may interfere with the test and cease any of these if you have been instructed to do so by your referring doctor or medical specialist.
• If you are pregnant, breastfeeding, or caring for a small child on the appointment day, please notify us in advance to receive special instructions.
• WEAR loose, comfortable clothes and suitable footwear for the stress test

Please call Lake Imaging immediately if you have any further questions or need any clarification.

When you attend your appointment at Lake Imaging you will be asked to answer a few safety questions, remove any jewellery, watches etc.

At Lake Imaging your stress test procedure will be carried out by a Nuclear Medicine Technologist who has a degree in Medical Radiation Science and is accredited by AHPRA.

A nurse will explain and prepare you for the stress test, which includes introducing an intravenous cannula (a small tube for taking blood samples and administering medicines) and electrocardiogram (ECG) monitoring during the treadmill exercise. A doctor will then speak to you before you start the exercise process. If exercise presents problems for you the doctor may suggest either trying gently exercising on the treadmill or an alternative stress method using a pharmaceutical.

After each injection, a gamma camera placed over the chest images (maps) the pattern of tracer accumulated in the heart’s left ventricle, giving information useful in diagnosing and managing conditions such as coronary artery disease, infarcts and diseases of the heart muscle (cardiomyopathy).

The images are usually combined with a low dose CT (Computed Tomography) scan performed at the same time on the same scanner. This combined SPECT/CT scan improves the accuracy of the information obtained, and adds only a few minutes to the duration of the procedure.

After the first scan is completed, the technologist will inject more MIBI, and ask you to wait, resting from 30 to 60 minutes before repeating the scan to show the heart perfusion at rest.

Please allow up to four hours for the entire procedure.

Radiation from the injected isotope diminishes to a very low level a short time after the procedure, and you are free to resume normal activities. If you are caring for a small child, or breastfeeding, we may ask to take some minor precautions.

If your results are needed urgently, or you have an appointment straight after your scan with your referring doctor or health care provider, Lake Imaging will arrange to have your results available immediately. Otherwise your referring doctor or health care provider will receive your report within 48 hours of your examination.

Please ensure that you make a follow up appointment with your referring doctor or health care provider to discuss your results.

Nuclear medicine examinations are considered very safe with almost no reported adverse reactions attributable to the radiopharmaceuticals used in these examinations.

Nuclear Medicine studies require very small doses of gamma radiation and are only performed where the benefits of the examination are deemed to outweigh any potential risks. At Lake Imaging you can be assured that using the latest technology and with staff trained in radiation reduction techniques, radiation doses are kept as low as reasonably possible.

If you are worried or concerned about your examination you should discuss this with your referring doctor or medical specialist before coming for your examination.