What should you know about metal and a PET scan?

PET detects radiotracer activity, whereas CT uses X-rays to create anatomical pictures. Jewellery, belt fittings, coins, phones, removable dental work, and clothing fasteners can create streaks or shadows on CT images. Internal items such as joint replacements, surgical clips, ports, stents, or pacemakers should be described to the imaging team. They may not require cancellation, but their location and material can affect positioning, scan quality, and how the images are read.

Before arrival, ask whether you should change clothes and remove removable metal. Bring details of implants or devices if you have them, including the device card when available. Tell staff about recent surgery, metal fragments, or difficulty lying in one position. Do not remove a medical device yourself. The team will decide what can stay in place and may adjust the scan or explain any limits in the images.

During the appointment, report new pain from positioning, dizziness, breathing difficulty, or a reaction after the radiotracer injection. Seek urgent help for severe breathing difficulty or collapse. A metal-related image artefact is usually a technical issue to discuss with the radiologist or referring clinician, not a diagnosis of disease.

Ask whether your implant changes the scan plan, which removable items must come off, whether prior device records are useful, and how any CT artefact will be handled in the report.