Patient Information

What is PET-CT?

There are two parts to a PET CT scan, both are performed on the same scanner at the same time. Positron Emission Tomography, or PET, uses small amounts of radioactive tracers to provide functional information and the CT (computed tomography) scan provides detailed anatomical/structural information. Both PET and CT scan information is displayed in the form of images and then combined or fused to form the PET CT. A specialist doctor will report on the PET CT images to diagnose, locate and assess a wide range of conditions in specific areas or the whole body. 

What are the alternatives?

Imaging with PET may detect early onset of disease or assess response to therapies earlier than conventional imaging such as ultrasound, a CT scan on its own, X-ray or a magnetic resonance imaging (MRI) scan. Other ways of looking inside the body include endoscopy or surgery. Your doctor will talk to you about your options and explain the benefits and risks of having a PET CT scan.

What to expect – Preparation

Our team will inform you of the exact preparation that you will need for the scan. It is very important to follow the preparation instructions, failure to do so could result in the scan being postponed or cancelled. 

Please NOTE: It is important to tell our team if you are pregnant or breastfeeding.

What to expect – During

A nuclear medicine technologist (a healthcare professional trained to handle isotopes) will administer an individually tailored injection into a vein (usually in your arm). Following this injection, you will be asked to rest quietly in your own uptake room - feel free to bring a book or tablet to occupy yourself as relatives and friends will be asked to wait in the waiting area. The scan time takes between 15-40 minutes (the exact scan time will be given before we start), please let the technologist know if you are not comfortable before the scanning starts to ensure we make you comfortable. 

What to expect – Afterwards 

The technologist will tell you if there are any special instructions you need to follow after the scan. In most cases you will be able to leave straight away, then eat and drink as normal. The isotope loses its radioactivity over time and will pass naturally out of your body. To assist passing the isotope out of your body, we encourage you to drink plenty of liquid and empty your bladder regularly. The amount of radiation in your body after the scan will be very small, if you have any concerns about exposure to radiation, please discuss this with one of our team. 

Getting the results 

The PET CT images will be electronically sent following the scan. A written report will be sent to the doctor who has requested your scan (usually within 48 hours), please inform us if you would like a copy of the report to be sent to your GP. Your doctor will be able to discuss the results with you at your next appointment. 

Pregnancy and breastfeeding

As a general rule, administration of any drug to a pregnant woman, including contrast media, needs to be carefully considered. It is important to tell our team if you are pregnant or breastfeeding.

18F-FDG

18F-FDG is a radioactive sugar that is absorbed into high-glucose-using cells. 18F-FDG is comprised of two components; a radioactive isotope of fluorine (18F) and a glucose (sugar) base tracer of fluorodeoxyglucose (FDG). Adverse reactions are extremely rare and the radiation exposure is comparable to a conventional CT scan. If you have any additional questions please feel free to talk about them with your doctor or one of our team before the scan.

18F-FDG PET CT is commonly used in the evaluation and management of many types of cancer including tumour diagnosis, staging, restaging, treatment monitoring, and radiation therapy planning. It is also used in the evaluation of myocardial viability, sarcoidosis, infection and assessment of neurological conditions including epilepsy and dementia. 

18F-NaF

18F-NaF is bone-seeking tracer used to image skeletal abnormalities. 18F-NaF is comprised of two components; a radioactive isotope of fluorine (18F) and base tracer of Sodium Fluoride (NaF). Adverse reactions are extremely rare and the radiation exposure is comparable to a conventional CT scan. If you have any additional questions please feel free to talk about them with your doctor or one of our team before the scan.

18F-NaF PET CT is commonly used in the evaluation and management for back pain, unexplained bone pain, abnormal radiographic or laboratory findings, osteomyelitis, trauma, inflammatory and degenerative arthritis, avascular necrosis, osteonecrosis of the mandible, condylar hyperplasia, metabolic bone disease, Paget’s disease, NAI, bone graft viability, complications of prosthetic joints, reflex sympathetic dystrophy and distribution of osteoblastic activity prior to administration of therapeutic radiopharmaceuticals for treating bone pain.

18F-PSMA

18F-PSMA is a prostate-specific membrane antigen (PSMA) and a recognized target for imaging prostate cancer. 18F-PSMA is comprised of two components; a radioactive isotope of fluorine (18F) and base tracer of DCFPyL (PSMA or PSR). Adverse reactions are extremely rare and the radiation exposure is comparable to a conventional CT scan. If you have any additional questions please feel free to talk about them with your doctor or one of our team before the scan. 

18F-PSMA PET CT is used for staging and re-staging prostate cancer. 18F-PSMA is the newest molecular imaging technique in New Zealand and we are proud to offer this service at Midland PET CT.