What a PET Scan Can Tell You

Positron emission tomography (PET) is a type of diagnostic imaging scan that is often included in diagnostic testing for cancer. If you or a loved one are scheduled for an upcoming PET scan at Excel Diagnostics & Nuclear Oncology Center in Houston, Texas, you might wonder what the scan will tell you. 

Below, Dr. Ebrahim Delpassand highlights the importance of a PET scan, what it can tell you, and how to prepare for it.

What is a PET scan?

A PET scan is a type of imaging test that reveals metabolic changes in your cells due to abnormal cell growth. The metabolic activity of your cells is important data because cancer cells have a higher metabolic rate (compared to noncancerous cells). This means that PET scans can help shed light on where cancerous cells are located in your body. 

PET scans detect high metabolic action in your cells through the use of a tracer. The tracer, which is a radioactive drug, is injected into a vein. Once the tracer is in your blood, it collects in areas of your body that have higher metabolic activity. The more concentrated areas of tracer (seen as bright spots on the scan) pinpoint the location of the disease. 

If you’re scheduled for a PET/CT scan, you receive both a PET scan and a computed tomography (CT) scan. The addition of the CT scan provides the team here at Excel Diagnostics with specific details about the cancer, including the tumor’s exact location, shape, and size.

What can a PET scan tell you?

PET scans can provide many details about cancer, including:

• The presence of cancerous tumors
• How far the cancer has spread 
• The location of solid tumors in your brain, thyroid, lungs, cervix, breast, esophagus, head and neck, lymphatic system, skin, colon, pancreas, and prostate

PET scans can also be used to evaluate how well your body is responding to current treatments. Although PET scans are most often associated with cancer diagnosis, PET scans can be used to evaluate brain and heart disorders. 

Preparing for a PET Scan

PET scans don’t require an overnight hospital day, but they do require a little bit of preparation, including the administration of the radioactive tracer. All prep included, the entire process can take up to two hours. We provide you with specific preparation instructions, but in general, you can expect to:

• Follow a specific diet before the scan, e.g. a high-protein, low carb diet 
• Refrain from eating six hours prior to the scan
• Refrain from exercise for a 24-hour period before the scan
• Monitor your sugar levels prior to the scan (blood sugar should be 180 or lower) 

In addition, if you have diabetes or take any medications, we may provide additional instructions. 

When you arrive for your PET scan, we provide a gown for you to wear. You will also be asked to empty your bladder. Once you’re ready for the scan, we administer the tracer, which can take up to 60 minutes to take effect. The tracer is injected into your vein, and once that is over, the PET scan is painless.  Simply lay on a padded bed while the scanner, which looks like a donut, takes the required images. 

After your PET scan, we encourage you to drink plenty of water to flush the tracer from your body.

We understand that preparing for diagnostic imaging tests can be unnerving, but know that a PET scan, like other imaging tests, can play a big role in shaping your treatment plan and assessing how well treatments work. That’s why our team is here to guide you through every step of your journey with diagnostic imaging. 

To learn more about the diagnostic benefits of a PET scan, schedule an appointment at our Houston, Texas, office through our online form. You can also reach Excel Diagnostics & Nuclear Oncology Center at 713-781-6200.