Cardiac sarcoid PET scan: what it shows

Sarcoidosis is an inflammatory condition that can affect several organs, including the heart. The scan commonly uses FDG, a radiotracer taken up by active cells. Preparation aims to reduce normal glucose use by the heart so abnormal uptake is easier to see. The PET images show metabolic activity, while the CT part helps locate that activity in the body.

Areas of uptake can have more than one explanation, so a scan is not interpreted alone and does not prove cancer. A clinician combines the images with symptoms, an ECG, heart imaging, blood tests, and medical history. The scan may help assess suspected cardiac involvement or monitor inflammatory activity after treatment.

Follow the centre’s exact preparation instructions. They may include a special low-carbohydrate meal plan, fasting, and avoiding strenuous exercise before the scan. Tell the team about diabetes, medicines, pregnancy or breastfeeding, and any difficulty following the diet. You will receive the tracer through a vein, rest quietly while it circulates, and then lie still while images are taken.

The appointment can take several hours because preparation and uptake time are part of the examination. Afterward, follow the department’s advice about fluids, activity, and close contact with young children or pregnant people. The tracer leaves the body naturally, but your centre’s instructions take priority.

Seek urgent medical help for fainting, severe chest discomfort, sudden breathlessness, or a sustained racing or irregular heartbeat. These symptoms can need immediate assessment and should not wait for a scan report. Contact the imaging team about increasing redness, swelling, or pain at the injection site, or any unexpected reaction after the appointment.

Ask what the scan is intended to answer, how the preparation will be adapted if you have diabetes, and whether any medicines need to be paused. Ask how the PET findings will be combined with your heart tests and when the result will guide the next decision.