What Is a PET Scan?

what is a pet scan

A PET scan is an advanced diagnostic test that detects the blood, oxygen and sugar used throughout the body. The procedure uses a radioactive tracer that helps the scanner find positrons in the body to diagnose or treat specific diseases. This guide will help you prepare for your upcoming PET scan so you can discuss any concerns with your doctor.

What Does a PET Scan Entail?

Before getting a PET scan, you will receive radioactive tracers to measure the sugar, blood and oxygen in your body. Depending on the examined body part, you’ll swallow, inhale or receive an injection of the tracers. The PET scanner uses these to analyze organ and tissue functionality.

Since the tracer groups together in parts with higher chemical activity, it can highlight specific illnesses. These will appear brighter on the PET scan than other organs and structures. Instead of a stand-alone PET scan, your doctor may recommend combining a PET scan with a computed tomography scan. A PET/CT scan allows physicians to assess metabolic and anatomic information in one test.

What Is a PET Scan Used For?

Physicians use PET scans to diagnose medical conditions and assess their patients’ responses to treatment. A doctor may recommend a PET scan to analyze your oxygen intake, blood flow and organ and tissue activity. With the sophisticated technology involved in a PET scan, a doctor can detect complex medical conditions on a cellular level. Physicians often prescribe PET scans to diagnose or treat the following diseases.

  • Cancer: Since cancerous cells have a higher rate of metabolic activity than noncancerous ones, they will appear on a PET scan in bright spots. A doctor can use this diagnostic imaging test to discover whether cancer has spread or if a specific treatment is effective. They can also determine whether cancer is recurring in a patient.
  • Heart problems: A PET scan can detect healthy tissue and parts with decreased blood flow throughout the heart. The areas with reduced blood flow show up in distinct colors and brightness levels. A doctor can use a PET scan to diagnose heart issues and develop possible treatment plans.
  • Brain disorders: A PET scan involves tracers attaching to glucose and other compounds in the body. The diagnostic testing detects which parts of the brain use more glucose for energy. A doctor can check for brain functionality and diagnose any abnormalities.

What Is the Prep for a PET Scan?

If you need a PET scan, your doctor will give you a set of instructions for how you should prepare for your specific diagnostic test. During this time, it is helpful for your doctor to know what medications you are currently taking.

Follow these tips for preparing for your PET scan.

  • Avoid strenuous activity: Since a PET scan uses glucose, you may need to stop engaging in strenuous physical activity or exercise a few days before the test. Exercise raises glucose uptake in skeletal muscles and might affect your test results.
  • Go on a low-carb and no-sugar diet: The day before your PET scan, at least 12 hours before your examination, your doctor will ask you to avoid foods and beverages with carbohydrates and sugar, which both elevate glucose levels in the body. You can eat a high-protein diet before your procedure, including non-starchy vegetables, meat, nuts and tofu. Eating sugar could skew the scan’s results because a PET scan detects your sugar metabolism.
  • Fast before the scan: If you are undergoing anesthesia for the procedure, you will need to avoid eating for several hours beforehand. Fasting lowers your blood sugar levels so the tracers can work efficiently. You cannot chew gum or suck on mints, hard candy or cough drops. However, you can drink water and take your prescribed medications.
  • Wear the proper clothes: The radiology technologist may ask you to change into a hospital gown. You will also need to take off any jewelry, including body piercings, because metal can affect the testing equipment.
  • Consider your medical devices and implants: Discuss any medical devices or implants you have. Pacemakers and artificial hips will not influence your PET-CT scan results. However, you should not have a PET-MRI if you have nonapproved medical devices or metal implants.
  • Tell your doctor if you are pregnant: Let your doctor know if you are pregnant or think you could be pregnant. The radiation from the PET scan is unsafe for your developing baby.
  • Pump and store your breast milk: You can pass the radiation from the PET scan to your nursing baby. If you are breastfeeding, you will need to pump and store your milk the day before the procedure. You shouldn’t breastfeed for 24 hours after the test.
  • Talk to your doctor about your diabetes: Your doctor will give you specific preparation directions if you have diabetes. Fasting before your test could affect your blood sugar levels. You can probably take your insulin as usual and have a small meal a few hours before your PET scan.

Is a PET Scan Safe?

A PET scan is safe and painless. Even though the procedure uses radioactive tracers, the exposure is minimal. Since the tracer contains glucose with a small amount of radioactive material, your body can quickly process and eliminate it. You can speak with your doctor if you have any concerns you may have. Remember, this test’s diagnostic benefits far outweigh any risks.

It is helpful to consider the possible side effects if you have some medical conditions.

  • Allergies: You may have an allergic reaction to the tracer, especially if you are allergic to saccharin, iodine or aspartame. The physician may prescribe you something different instead.
  • Pregnancy: You should not get a PET scan if you are pregnant or think you might be pregnant. The radiation involved in the procedure is unsafe for a growing fetus.
  • Claustrophobia or fear of needles: The test may be uncomfortable for you if you are afraid of enclosed spaces or needles. Discuss your options with your doctor to make your procedure more pleasant for you.

You may also have swelling, bleeding or bruising from the injection.

Schedule Your PET Scan With Impression Imaging

You can complete your prescribed PET scan at Impression Imaging in South Florida. Our specialized team of radiologists strives to give you the highest-quality care during your procedure. Request an appointment online or call (954) 580-2780 for more information.

Meet Our Radiologists

Michael Fagian, MD

Michael Fagien, MD

Nuclear Radiologist

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David Clayman, MD

David Clayman, M.D.

Neuro Radiologist

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