PET scan for the liver: what to know

For a PET-CT, an FDG radiotracer is injected and allowed time to circulate before imaging. The CT component shows the liver's shape and nearby structures; the PET component shows areas using more tracer. Activity can occur with cancer, infection or inflammation, so the scan does not identify the cause on its own.

The liver may be assessed as part of a wider scan, including nearby lymph nodes and distant organs. Doctors compare the images with CT or MRI findings, symptoms, examination and laboratory results. A PET-CT can help locate a suitable area for further assessment, but the next step depends on the whole clinical picture.

Follow the centre's instructions about fasting, water, medicines and diabetes. Tell staff about pregnancy, breastfeeding, kidney problems, diabetes or previous reactions to injections. Stay warm and relaxed during the uptake period, and avoid strenuous activity if instructed because muscle activity can affect image interpretation.

Bring earlier imaging and relevant reports. Ask when and how the result will be explained. Depending on the findings, your team may recommend another scan, a biopsy, or evaluation for a condition such as lymphoma or cancer of unknown primary. Do not interpret a single bright spot without the report and clinical context.

Tell the imaging team immediately about breathing difficulty, facial swelling, widespread rash or feeling faint after the injection. Seek urgent care for severe abdominal pain with vomiting, yellowing of the skin with confusion, chest pain or trouble breathing. Contact your treating team if new jaundice, persistent vomiting or worsening abdominal swelling develops while the cause is being investigated.

Ask why PET-CT is being recommended, whether fasting or medicine changes apply, what the CT and PET parts can clarify, and whether another imaging test or tissue sample may be needed. Ask which symptoms should prompt a call and when the final report will be reviewed with you.