Whether you’ve been referred for a PET CT scan or are simply curious about what it involves, this guide covers the essentials: what a PET CT scan is, how it works, and what to expect during the procedure.
What Is a PET CT Scan?
A PET CT scan combines two types of imaging:
- Positron Emission Tomography (PET): This technique detects metabolic activity within tissues using a small amount of radioactive material (called a tracer).
- Computed Tomography (CT): This provides detailed anatomical images using X-rays.
By combining these two scans, doctors can see both the structure of organs and tissues and how they’re functioning, offering a comprehensive picture in one procedure.
Why Is a PET CT Scan Done?
PET CT scans are most commonly used for:
- Cancer diagnosis and monitoring: To detect tumors, evaluate the spread (staging), or assess response to treatment.
- Heart disease: To evaluate blood flow and detect damaged heart tissue.
- Brain disorders: To study conditions like epilepsy, Alzheimer’s disease, or brain tumors.
This hybrid imaging technique helps doctors pinpoint abnormalities more precisely and choose the best treatment options.
How Does the Procedure Work?
- Tracer Injection: A radioactive tracer, often a form of glucose (FDG), is injected into a vein. Cancerous or diseased cells absorb more of this substance because they are more metabolically active.
- Waiting Period: After the injection, you’ll wait around 30–60 minutes to allow the tracer to circulate and be absorbed.
- Scanning: You’ll lie on a table that slides into a large machine resembling a tunnel. The scan typically takes 20–45 minutes.
- Aftercare: There’s no recovery time, and you can usually resume normal activities right after the scan. Drinking plenty of water helps flush the tracer from your body.
Is It Safe?
Yes, PET CT scans are considered safe for most people. The amount of radiation used is low and carefully controlled. However, always inform your doctor if you are:
- Pregnant or breastfeeding
- Diabetic (as this can affect the tracer uptake)
- Allergic to contrast materials (if a contrast-enhanced CT is needed)
Preparing for a PET CT Scan
To get the most accurate results:
- Fast for 4–6 hours before the test
- Avoid strenuous exercise for 24 hours prior
- Wear comfortable clothing without metal zippers or buttons
- Follow any specific instructions from your healthcare provider
Final Thoughts
A PET CT scan can be a critical step in accurately diagnosing and managing complex health conditions. While the idea of radioactive tracers and large machines might sound intimidating, the procedure is non-invasive, relatively quick, and incredibly informative.
If your doctor has recommended a PET CT scan, understanding the process can ease any anxiety and help you prepare effectively.