A PET-CT scan takes images of a targeted area or a particular organ in the body. It is a combined scan using Positron Emission Tomography (PET) and Computed Tomography (CT). During the scan, the patient is injected with glucose containing a small dose of a radioactive agent.
The scan reveals parts of the body that consume more glucose. Areas with a high glucose intake mean that cells are growing at a high rate, which could be indicative of cancer. PET-CT scanning also determines the grade of the tumour, indicating how fast it can grow and spread to other areas. It also reveals whether the tumour has spread already and where. Doctors also use this imaging technique to monitor the efficacy of your treatment plan.
A PET-CT scan usually takes 30-40 minutes but the entire procedure can last from 2-3 hours. After you change into a hospital gown, you will be intravenously given a dose of glucose. Then you will be asked to wait in an isolation room for 1½ hours for the glucose to circulate throughout your body. During the wait, you will be asked to drink 3-4 glasses of water. Depending on your clinical findings, the water may contain some medication.
The scanning machine is noiseless and has a tunnel-shaped scanner. You will lie on an examination table, which will slide under the scanner. The scanner will take images of your body from different angles. The doctor will then verify the quality of the images and you will be allowed to leave.
Your doctor will give you specific instructions prior to the scan, which has to done on an empty stomach. You cannot have metal objects, including watch and jewellery, on your person during the scan. Please feel free to ask your doctor about any concerns you may have.