What you need to know about PET/CT scans

Published: Tuesday, June 4, 2024
Justin Woodsmall CNMT, BS
Nuclear Medicine Lead Technologist

Understanding medical procedures can be a bit overwhelming, especially if you don’t have a medical background. If you or a loved one is scheduled for a PET/CT scan, you might have questions about what it is and what to expect. Let’s break it down into simple terms.

What is a PET/CT scan?

PET/CT stands for Positron Emission Tomography with Computed Tomography. A PET/CT scan is a special type of medical test that helps doctors see what’s happening inside your body. It combines two different scans.

  • PET – looking at physiology. This part of the test uses a small amount of a radioactive substance, called a tracer, to highlight areas in your body that might be sick, like cancer.
  • CT – looking at anatomy. This part uses X-rays to take detailed pictures of your body’s organs and structures.

With PET we are looking for an uptake region, or “hot spots”, that would indicate increased metabolic activity, such as cancer or infection. PET/CT can also look at metabolic function of the brain to include Alzheimer’s and Dementia.

Together, these scans give doctors a complete picture of your health, showing both how your body is working and what it looks like inside.

Why do doctors use PET/CT scans?

PET/CT scans are very useful for many reasons:

  • Finding Cancer: These scans can help find cancer, see how big it is, and check if it has spread.
  • Checking Treatment: They can show if cancer treatments are working.
  • Heart Health: PET/CT scans can check for heart problems by showing areas where your heart might not be getting enough blood.
  • Brain Disorders: These scans can help diagnose brain problems like Alzheimer’s disease and epilepsy.

How does a PET/CT scan work?

These images are done on one camera, with the patient in the same position for both image sets, so that the images can overlay each other. When physiology and anatomy are put together it gives a doctor who specializes in reading these scans, called a radiologist, a better view of what is going on with a patient.

Here’s what you might expect when getting a PET/CT scan:

  • Preparation: You might need to avoid eating for several hours before the scan. Drink water and follow any specific instructions from your doctor.
  • Tracer Injection: PET/CT uses radioactive isotopes that we inject into a vein. The injections take from 30min to 90min to uptake into the patient’s body. During that uptake time at NGMC, the patient sits alone in a quiet room that is specifically designed for the wait period. The patient will have a large comfortable reclining chair in a dimly lit room that help the patient to relax during the wait time. The patient also receives a warm blanket and pillow if they would like it to help them relax during this waiting period.
  • Scan: The patient will lay down on their back for the PET/CT scan. The CT scan is done first prior to the PET scan and is used to align the region of images that are to be taken. The scanner is quiet because the PET part uses a detector that receives radiation from the injected tracer to create images.
  • Results: A radiologist will look at the images and send a report to your doctor.

Learn more

A PET/CT scan is a powerful tool that helps doctors understand what’s happening inside your body. It’s especially helpful for detecting and monitoring diseases like cancer, heart conditions, and brain disorders. If you have any concerns or questions, talk to your healthcare provider—they’re there to help you understand and feel comfortable with the process.

PET/CT scans are offered in Medical Plaza 1 in Braselton and Medical Park 1 in Gainesville. For more information about imaging services at NGMC, click here.