What can a PET scan show?

After FDG Radiotracer enters the body, tissues that use more glucose may appear more active. A PET-CT Scanner places that activity beside detailed CT images, so the radiologist can relate a finding to an organ, lymph node or other structure.

The scan may help assess a known tumour, look for spread, compare activity before and after treatment, or investigate unexplained findings. Infection, inflammation, recent surgery and some normal organs can also appear active. A quiet area can be useful information, but it does not answer every clinical question.

Your doctor reviews the report with examination findings, blood tests and any biopsy or earlier imaging. Preparation commonly includes fasting as directed and avoiding strenuous activity before the appointment. Keep a record of medicines and tell the team about diabetes, pregnancy, breastfeeding or recent treatment, because these details can affect preparation or interpretation.

Ask for prompt advice if you feel unwell during preparation or after the tracer, or if you cannot complete the scan. Get urgent care for severe breathing difficulty, collapse, or swelling around the mouth or throat. A worrying phrase in a report needs timely discussion, but it should not be read as a diagnosis without the clinical context.

Ask what the scan was intended to assess, which findings are expected, whether another test is needed, and when the full report will be discussed with you.