What to do before a PET scan

 Preparation for a PET scan begins several days before the scan. You will receive a complete set of instructions from your doctor telling you what to do. Typically, your doctor will recommend limiting strenuous physical activity for 24 to 48 hours before the test.

 Prepare for the PET Scan the day before

You will need to follow a specific PET scan preparation regimen for 24 hours before the scan. You should avoid sugar altogether and limit carbohydrates as much as possible. “Doctors use a sugar-based tracer to create your PET image. Therefore, other sugars present in your system will be detected by the analysis, creating a misleading picture. Foods to avoid when preparing for a PET scan include:

• Cereal
• pasta
• Beans
• Fruits and fruit juices
• Honey, desserts, and sweets
• Starchy vegetables such as corn, peas, and potatoes
• Nutritional smoothies and shakes
• bread
• rice
• sauce
• Jams and jellies
• Drinks containing caffeine
• yogurt
• Dairy, including non-dairy milks such as oat, almond, or soy milk
• Wine

This list is not exhaustive, so it’s helpful to focus on what you can eat rather than what you can’t eat. Stock up on these foods for 24 hours before your exam:

• Meat and poultry
• Hard cheese
• Non-starchy vegetables like spinach, green beans, and broccoli
• nuts
• Eggs
• Tofu
• Margarine, butter, and oil

If you have diabetes, it is essential to talk to your doctor about adjusting your diet and medications. Controlling blood sugar levels for 48 hours before the test is necessary to get accurate results. You should also tell your doctor about any supplements or over-the-counter medications you are taking.

Six hours before your PET scan

Six hours before your PET scan, you will need to stop eating and drink only water to prepare for the scan. Drinking water is encouraged and may improve the precision of your results, so consider carrying a water bottle to maximize your fluid intake. If you have diabetes, you may take your medicine up to four hours before your exam. You will be asked to wear a medical gown or hospital gown and to remove all jewelry, as metal can interfere with the test equipment. Medical devices, such as an artificial hip or pacemaker, will not affect your results.

What to do during a PET scan

On the day of your PET scan, follow the instructions and relax. One to two hours before the analysis, “The medical staff will inject you with a dose of radioactive tracer that the study will detect.” The tracer is a radioactive isotope of glucose, called fluorodeoxyglucose (FDG). It accumulates in malignant cells, helping doctors pinpoint the problem in your body. The injection will feel just like a regular vaccine: gently pinch where the needle goes in, and you may feel a cold feeling in the arm. The marker will not make you feel any different or cause pain during the procedure. You will need to wait 1 to 2 hours at the facility for your body to absorb the tracer, and you will need to rest quietly during this time. Before your analysis, you can ask your technician any questions you have about the procedure. It is rare but possible to have an allergic reaction to the tracer. You are more likely to have an allergic reaction if you have:

• Allergy
• Asthma
• Blood cell disorders
• dehydration
• Heart or kidney disease
• Medication regimen includes beta blockers or nonsteroidal anti-inflammatory drugs (NSAIDs)

To self-scan, wait about 30 to 45 minutes. You will be asked to lie flat on a narrow table that slides out from the circular PET machine. You will need to stay as still as possible and raise your arms above your head to get a clear image. The technician may ask you to hold your breath for a few seconds at a time. There will be no pain during the procedure, but some people who are afraid of enclosed spaces may feel nervous being inside the camera. The PET machine will make a lot of clicking and buzzing sounds as it rotates around your body, which can sometimes confuse some people. Try to relax and breathe slowly throughout the procedure. “Once the system saves the image completely, the technologist will slowly remove you from the machine, and the scan will be complete.”

What to do after a PET scan

Once the scan is complete, you can resume your activities as usual unless your doctor gives you specific instructions. Even though the dose of radioactive tracer is very low, you should still avoid contact with pregnant women and newborns for 12 hours after the test as a precaution. To help remove the tracer from your system, drink plenty of water and other hydrating liquids.

Most people remove all traces after two days. In the days after the PET scan, a specialist will evaluate the images and share their interpretation with your doctor. The images produced by a PET scan show bright spots that indicate where chemical activity is highest, providing radiologists with information about the function of your body’s organs and tissues. You usually won’t have to wait more than two business days for your doctor to receive the information, and you’ll discuss your results at your next appointment.

Select an image for your PET Scan.

By following your doctor’s instructions for preparing for a PET scan, you can improve the clarity of the results, and your doctor can obtain important information about your condition. Choosing the right imaging center can significantly improve your experience and minimize stress during this essential procedure. Envision Imaging is committed to creating a safe and hospitable environment for all patients undergoing imaging tests, including PET scans.

Our compassionate approach includes a commitment to accurate image quality and improving physician workflow by quickly delivering results to you through the electronic medical record (EMR). Browse our websites to request your next diagnostic imaging appointment. Our world-class facilities, attentive care, and accurate results ensure an enjoyable and trustworthy experience.

Safety tips for patients before the exam

• Please let us know if you have any allergies or adverse reactions to the medication. If you are pregnant or may become pregnant, tell your doctor or technician.
• Please leave your valuables at home or in your hospital room.
• Please let us know now if you require an interpretation service; we can arrange it.  
• Bring a list of your current medications (outpatient).

Prepare for procedures

• You have to ask to follow a carbohydrate-restricted diet for 24 hours before your appointment.  
• Do not eat or drink anything except water for 6 hours before the test. Drink as much water as possible until you reach your destination.
• Routine medications are used unless otherwise indicated. If you have diabetes, you may take your diabetes medication at least 4 hours before your exam.
• Arrive 15 to 30 minutes before the PET scan.  
• The technician will verify your identity and the test requested.  
• You will receive a contrast screening form to complete.
• In some cases, your doctor may order tests before using contrast material.
• Typically, contrast material is injected into a vein to improve image quality throughout the body. “If the radiologist finds it helpful, the radiologist will place a small intravenous (IV) line into a vein in your arm. Through this IV line, medical staff will introduce contrast agents and isotopes. Your kidneys will excrete the contrast agent.”

During the exam

• Exam times vary, but the average is about 2 hours.
• The technician will place you on the exam table and instruct you to stay still or hold your breath.
• You will have the opportunity to ask the technologists questions.

After the procedure

• You should drink about 5 glasses of water.
• Breastfeeding mothers should wait 24 hours before resuming breastfeeding.
• If you experience symptoms such as a stuffy nose, itchy eyes, hives, rash, sneezing, restlessness, tremors, pain, nausea, vomiting, or dizziness, please notify staff immediately. Staff have to prepare to handle these situations.

Final thoughts

Proper preparation for a PET scan is an essential step in obtaining accurate and meaningful results. By following dietary restrictions, fasting instructions, medication instructions, and activity restrictions, you will help ensure the test’s success and enable your doctor to develop the best possible diagnosis and treatment plan.

If you have any doubts or special medical conditions, always consult your doctor or imaging center before your appointment. Good preparation will bring more clarity, better care, and better outcomes.