What should you know about a fluorodeoxyglucose PET scan?

FDG behaves in a similar way to glucose, so tissues that use more glucose can appear more active on the scan. A PET-CT Scanner combines this activity map with CT images that show anatomy. Doctors may use the result to help locate a tumour, assess lymph nodes or look for disease elsewhere. Increased activity is not specific to cancer; infection, inflammation and normal organs can also take up FDG. The scan is interpreted alongside your symptoms, examination and other tests.

Follow the imaging centre's fasting instructions and tell the team about diabetes, medicines, pregnancy or breastfeeding. Avoid strenuous exercise before the appointment if instructed, because active muscles can affect the images. After the tracer is given, you usually rest quietly while it travels through the body, then lie still during imaging. Drink fluids afterward if your team recommends this. Results may be discussed with you after a radiologist reviews the images; an FDG PET scan alone does not establish a diagnosis.

Contact the imaging team promptly if you develop marked swelling, spreading redness or worsening pain where the tracer or an intravenous line was given. Seek urgent medical help for trouble breathing, facial swelling, fainting or severe weakness. If you have diabetes, ask how to manage food and medicines around the appointment, since fasting can affect glucose control.

Ask what the scan is intended to answer, whether you need to fast, how diabetes medicines should be handled, when results will be available, and which follow-up test will clarify an abnormal area.