A cardiac positron emission tomography (PET) scan is an imaging technique that uses radioactive tracers to evaluate the blood flow to the heart. The scan provides information about the working of the heart and its tissues at the cellular level. It is also used to assess the extent of heart damage due to heart attack and diagnose coronary artery disease.

How is Cardiac PET Scan performed? :

An IV (intravenous) line is connected to the patient’s arm, and a radioactive tracer is injected via this. Natural body compounds like glucose or water labeled with a small amount of radioactive material (rubidium-82) are commonly used as tracers for PET scans.

The patient is then asked to wait for an hour to ensure that the tracer gets absorbed by the organs and tissues. During this time, electrodes are attached to the patient’s chest to record the electrocardiogram (ECG). After this period, the patient will lie on a narrow table that slides into the tunnel-shaped PET scanner.

The patient is instructed to be completely still during the scan. A gamma-ray camera that detects the gamma rays emitted by the tracer is used to produce images of the heart from all directions and angles. The 3 – dimensional (3D) images of the heart are then created by a computer and viewed by the doctor. The technician generally takes a baseline picture of the heart before injecting the tracer.

This scan can also be done in conjugation with a nuclear chemical stress test. In such cases, the images of the heart are captured both before and after the test to examine how well the heart takes up the tracer.  

Single Photon Emission Computed Tomography (SPECT):

 A SPECT scan of the heart is also a nuclear imaging test that follows the same procedure as a PET scan. The radioactive tracer used in this scan is Technetium-99m. SPECT scans are generally less popular than PET scans; as they produce low-resolution images that do not provide a quantifiable estimate of blood flow.

Are there any risks involved in it? :

  It is a relatively safe test as a small amount of radioactive tracer is only used. Women- pregnant or breastfeeding should consult with the doctor beforehand as the radiations may harm the baby.

FAQs: Cardiac PET Scan

What are preparations required from the patient? The patient must fast for 4 to 6 hours before the test. All caffeinated products must be avoided for 24 hours before the test. The patient must notify the doctor if he/she is diabetic and takes insulin.  

How long does it take?  It takes 1 to 3 hours to complete this test.

Who performs it? This scan is performed by a PET/CT technologist.

How much does it cost? The cost of a PET scan ranges from Rs. 15K to 27K.

When can I go home after the procedure? The patient can resume his normal activities and go home immediately after the test.

References:

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