What is PET-CT?

Positron Emission Tomography (PET) is an imaging technique which can provide information about cellular function. 18F-deoxyglucose (FDG) is a glucose analogue labelled with positron emitting fluorine. It is injected into the patient and because malignant tumours have a higher glucose metabolism, the tumour cells take up more FDG than the surrounding normal tissue and therefore emit greater numbers of positrons. The malignant cells show up as increased activity on the scan. CT is fused with PET (PET/-CT) to allow the exact site of the tumour to be identified. FDG is made in a cyclotron and ordered specially for each patient and transported to the unit on the day of the scan. The FDG has a short half life (110 minutes) and is dispatched for delivery immediately after production. Once delivered, it is administered at a calculated time ensuring the correct dosage. It is imperative that the patient arrives at the unit punctually.