Is a PET scan the same as a CT scan?

CT uses X-rays to create cross-sectional pictures of organs, bones and other tissues. PET uses a small amount of FDG Radiotracer, which collects in areas using more glucose than nearby tissue. A PET-CT Scanner combines the activity map with CT anatomy, helping the team see where an active area is located.

In oncology, this combination can help assess a known cancer, look for disease elsewhere, or investigate cancer when its primary site is not clear. Increased activity is not a diagnosis by itself; inflammation and healing can also change the scan appearance.

Follow the imaging centre's instructions about eating, drinking, medicines and blood glucose. Tell the team if you are pregnant, breastfeeding, diabetic, or unable to lie still. During the visit, the tracer is given, you rest quietly, and then images are taken while you remain still. Ask when normal activities and close contact with children or pregnant people are appropriate after the scan.

Contact the imaging team promptly if you develop unexpected symptoms after the appointment, or if you could not follow the preparation instructions. Seek urgent help for severe breathing trouble, fainting, or swelling of the face or throat. The report should be interpreted alongside your symptoms, examination and other tests.

Ask which part of the scan is answering your clinical question, whether a PET-CT is needed instead of one scan, and what an area of increased or reduced activity could represent.