What to expect after a PET-CT scan

Drink fluids if you have not been told to restrict them, empty your bladder regularly and keep the written discharge advice. The radiographer does not usually give a full interpretation immediately; a specialist reviews the images and sends a report to the clinician who requested the test.

PET-CT combines information about tissue activity with detailed body images. A commonly used FDG radiotracer behaves similarly to glucose, so areas using more glucose may appear more active. Activity is not automatically cancer: inflammation, infection, normal organs and healing tissue can also take up tracer.

The final report is interpreted alongside your history, examination and other tests. It may describe areas that need comparison, follow-up imaging or a biopsy rather than giving a diagnosis on its own.

Follow the centre’s advice about close contact with pregnant people and young children because recommendations depend on the tracer and local protocol. If you were given a sedative, contrast material or medicine to alter blood glucose, use the additional discharge instructions and arrange help getting home when directed.

Confirm who will discuss the result and when. Continue prescribed medicines unless the imaging team gave different instructions, and tell the referring clinician about any symptoms that have changed since the scan was booked.

Seek urgent care for trouble breathing, swelling of the face or throat, collapse, or a rapidly spreading rash after an injection. Contact the imaging centre or a clinician for persistent pain, redness or swelling around the injection site, repeated vomiting, or any symptom specifically highlighted in your discharge instructions.

The small puncture site can be tender or bruised, but increasing warmth, drainage or worsening swelling deserves assessment. Mention kidney disease, diabetes or fluid restriction when asking for advice, because generic hydration guidance may not fit your situation.

Ask what the scan was designed to clarify, whether the findings match earlier imaging, and whether any active area could have a non-cancer explanation. Also clarify whether you need another scan, tissue sampling, a change in treatment or no immediate action.