Positron emission tomography (PET) scans have become commonplace in the medical field in recent years. This type of imaging test essentially measures the metabolic activity of your cells. Excessive metabolic activity is harmful to the cells and a likely indicator of DNA damage, cancer or other serious diseases. PET body scans help doctors discover these imbalances and diagnose individuals accurately to provide appropriate care. Below, you’ll learn how PET scans work and what doctors use them for.
How Do PET Scans Work?
A PET scan measures metabolic activity in the body tissue’s cells. First, a small dose of radioactive glucose, a type of sugar referred to as the radiotracer, is administered intravenously, usually within your hand or arm. The PET scanner then takes images of where the glucose collects in the brain because it accumulates around malignant cells.
The PET scanner can detect malignant lesions that magnetic resonance imaging (MRI), computerized tomography (CT) scans or X-rays missed, allowing medical professionals to provide an accurate diagnosis. PET scans help doctors see biochemical changes within the body, such as the metabolism in body tissues or areas where cells are more active than usual. While PET scans work similarly to CT scans, PET functions in real time, allowing radiographers to detect cellular changes earlier than other methods.
Sometimes, PET scans are combined with CT scans, called PET-CT scans. Combining the two scans allows for more detailed imaging for accurate diagnosis. If you’re going in for a PET scan, you can expect the exam to last between 45 and 60 minutes so the radiographer can take all the necessary images. You’ll likely need to be in the department an hour beforehand to receive a radiotracer injection or the radioactive glucose required for the scan.
What Are PET Scans Used For?
PET body scans help doctors identify active areas such as the heart and brain, looking for conditions or signs of conditions that may be present. These scans will also measure oxygen intake, blood flow and the metabolism of tissues or organs:
- Heart problems: PET scans are ideal for revealing decreased blood flow in the heart vessels. Unhealthy heart tissue won’t take in as much of the radiotracer, making them easy to identify. Varying colors and brightness levels help doctors identify different levels of tissue function, allowing you and a medical professional to make informed decisions when moving forward with your treatment.
- Brain disorders: The radiotracer will be more active in specific parts of the brain than others, allowing doctors to identify various central nervous system (CNS) conditions, such as epilepsy and Alzheimer’s disease. PET scans can also help determine the severity of these conditions, assisting with the next steps for treatment.
PET scans diagnose numerous conditions but are primarily used with cancer patients. Now a leading practice in oncology, PET scans are used in a variety of applications, including staging, assessment, restaging and surveillance. PET scans help radiographers and doctors by:
- Depicting the effectiveness of current treatment
- Identifying the best place in the body for a biopsy
- Checking for new cancer growth, both after treatment and during followups
- Determining the best course of action for radiation therapy
- Restaging a cancer diagnosis
PET scans are a vital tool to help medical professionals discover different conditions in patients and find the best form of treatment to garner the most success. PET scans are particularly successful at determining whether a tumor is malignant or benign, especially when combined with CT scans, helping doctors decide which treatment best suits each individual.
PET scans detect most types of solid tumors that can develop into cancer. In detectable tumors, cancer cells appear on PET scans as bright spots, indicating a higher metabolic rate than normal cells. PET scans can find these calls in many types of cancer, including:
- Brain
- Breast
- Lung
- Prostate
- Pancreatic
- Skin
- Lymphatic
- Thyroid
- Cervical
- Esophageal
- Head and neck
- Colorectal
How to Prepare for a PET Scan
Preparing for a PET scan can limit surprises and ensure you’re comfortable throughout the exam. You should take different steps before, during and after the scan, which we outline below.
Before the Scan
Before the scan, avoid eating for four to six hours, limiting yourself to unflavored water. If you have diabetes and not eating is a problem, call your doctor to determine if you need to adapt your diet before the scan. Your doctor may also ask you to avoid strenuous exercise for up to 24 hours before your appointment.
Other ways you’ll need to prepare for the scan include:
- Dressing accordingly: A technologist may ask you to change into a medical gown during your scan, so you’ll want to wear loose-fitting clothing that’s easy to change. If you’re not required to change, wearing loose clothing will help keep you comfortable. You’ll need to remove any jewelry, piercings or other metal items, so they don’t interfere with the scan. If you have any metal implants, let your doctor know ahead of time.
- Bringing your medical records: Your medical history is essential before performing any exam, including PET scans. Bring your medical records or be aware of what you’ve done in the past, as your technologist will likely ask you questions about your history, including other scans or surgeries you may have had. You’ll also want to mention what medications you’re taking and what you’re using them for.
- Reviewing your instructions: You’ll likely receive instructions letting you know what you can eat and drink before the procedure. Review these instructions carefully to ensure you don’t miss anything before the exam.
- Allotting plenty of time: You’ll likely be at your appointment between one to three hours since a doctor will need to give you the radiotracer, giving it up to 90 minutes to travel through your body. The scan could take up to an hour. You’ll want to plan your day so you have plenty of time to complete the exam and the rest of your daily activities.
- Leaning on family or friends: If you’re anxious about your scan, talking with friends or family members can help you feel more comfortable. You may also be able to bring support into the facility with you if they approve of guests.
During the Scan
Be prepared to have an injection for the radiotracer. After the tracer is injected, you will be asked to rest for 30 to 60 minutes. You should also be prepared to lie on a surface that slides into a large machine with a doughnut shape in the middle. At specific points during the scan, the technician may ask you to hold your breath for a few seconds to get clear images, as moving too much can cause the images to be inaccurate.
If you’re anxious about your exam, talk to your technician. They can help you be more comfortable, making potential accommodations as necessary to help get the images needed for your future treatment. Be sure to inform your radiographer if you feel uncomfortable at any point during the exam — they will do what they can to make the process easier.
After the Scan
Once the scan is complete, you can continue eating, drinking and exercising as usual. It’s a good idea to drink more water shortly after the exam to flush out the dye or radioactive sugar. You’re free to go about your day when the scan is done. Doctors advise you to:
- Avoid contact with pregnant women, babies and children for 6 hours after the scan.
- Wait one day before operating a vehicle.
- Carry your appointment letter if traveling within the week.
Trust Impression Imaging as Your PET Scan Expert
Impression Imaging utilizes advanced PET scanners to help doctors diagnose and monitor different conditions. Once we perform our scans, we send the necessary information to your doctor to ensure they have everything they need to coordinate your care. We aim to make the process as easy as possible for our patients, providing quick scheduling and quality customer service.
If you’re interested in our imaging services, fill out our contact form to get in touch today!
