Is Contrast Used in — a PET-CT Scan?

No. The radioactive tracer is always given — that is the PET part. Intravenous contrast is added only when the oncologist or radiologist decides the clinical question requires it. Many scans, particularly those focused on metabolic staging or treatment response, are done without it. Your referral or the imaging protocol will confirm whether contrast is planned for your appointment.

Tell the radiographer immediately if you notice tightness in the chest, difficulty breathing, a spreading rash, or anything that worries you. Imaging centres that give intravenous contrast are equipped and staffed to respond to reactions, including severe ones. If symptoms continue or worsen after you leave the centre, go to the nearest emergency department and tell them you received intravenous contrast dye.

Kidney function is checked before contrast is given in most protocols because the contrast dye is cleared through the kidneys. Reduced kidney function affects how safely this can happen. Your oncologist and imaging team will review your results and decide whether contrast is appropriate, whether the protocol needs adjusting, or whether a plain PET-CT is the better choice. Tell your team about any kidney condition before the appointment.

Yes. Metformin interacts with intravenous contrast in certain situations, particularly when kidney function is reduced. Standard protocols may require you to hold it before or after the scan. Your team will advise what to do based on your kidney results and the specific protocol. Do not stop or change any medicine without being told to — just report that you take it.

The cannula insertion feels similar to a blood test — a brief sting. Once contrast is injected you may notice a warm flush moving through your body, a metallic taste, and sometimes a momentary sensation as though you have urinated — you have not. These are expected and pass quickly. If you feel anything beyond that, tell the radiographer straight away.

Yes, in most cases. The contrast itself, the monitoring it requires, and the additional clinical time add to the cost. The difference varies by centre and by the protocol ordered. When CION coordinates your scan with a partner imaging centre, ask at booking what the total cost includes and confirm the amount before attending. Cost figures are indicative and can change.

It depends on the clinical question. Contrast improves visibility of blood vessel anatomy and soft-tissue boundaries in some cancer types and staging situations, and in those cases adds real value to the report. In others, the metabolic information from the radioactive tracer is what matters and contrast does not change the conclusion. Your oncologist and radiologist choose the protocol based on what they specifically need to see.

Both are important to declare before any contrast injection. The imaging team and your oncologist will weigh the clinical need against your situation carefully. A plain PET-CT or a different imaging approach is sometimes the preferred choice. If you are breastfeeding, the team will advise specifically how long to pause after contrast. Always declare this before the scan, not at the last moment in the room.