Your practitioner has ordered a PET scan. In this type of imaging a radioactive tracer called FDG is used. FDG mimics glucose, the body’s main sugar. Since people with diabetes have trouble processing glucose, the FDG may not work as well unless the blood sugar is well controlled. Please follow these instructions so your PET scan will be of good quality.
What to expect
This procedure is being done to produce detailed images of your body. Before the procedure you will receive a small injection of radioactive sugar (called FDG) into a vein. You will be asked to relax in a recliner for up to one hour while the FDG travels through your body. It is important that you do not move during the exam. The actual scan will be completed in 45 – 60 minutes. Please plan for your appointment to take 2-3 hours.
You will be asked to eat a carbohydrate free diet the day before and not eat anything after midnight the morning of the PET scan. You may drink water.
If you take medications for diabetes, adjustments may be needed the day before and day of the procedure.
If you have symptoms of low blood sugar while fasting you should treat it with your usual method, typically with juice, food, or glucose tablets.
2-3 weeks before your PET scan
It is important to know ahead of time if your blood sugar will be 200 or less prior to the PET scan. To ensure that your blood sugar is within the limits to perform the scan, you will be asked to do a “practice run” 2 – 3 weeks before your scan.
- Before you do the “practice run”, consult your diabetes provider, if needed, for medication dose adjustments.
- Follow “The Day Before Your PET Scan” directions below.
- During this time, test your blood sugar before meals, bedtime, 3 a.m., and first thing the next morning. Log the results.
- One of our radiology techs will call you to discuss your blood sugar results. If your blood sugar is over 200 on the day before the test the test will be canceled.
The day before your PET scan
- Avoid strenuous exercise within 24 hours of your appointment.
- Eat a high protein/low carbohydrate diet. Some examples of foods you may eat include
- Eggs (any style) • Meat (beef, pork, chicken, fish, bacon, sausage) • Non starchy vegetables such as broccoli, cauliflower, green beans, lettuce • Cheese • Black coffee, sugar free teas • Diet soda • Water
- Avoid eating carbohydrates such as fruit, milk, pasta, cereal, bread, rice, and starchy vegetables (examples: peas, potatoes, corn, chili beans).
- Test blood sugars before each meal, bedtime, 3 a.m. and first thing the next morning. Log the results.
- If you use a sliding scale or correction factor and your 3 a.m. blood sugar is above 200, correct blood sugar as instructed. No additional insulin can be given after 3 a.m.
- Do not eat anything after midnight. You may drink water.
On the day of your PET scan
Check your blood sugar after the overnight fast to make sure it is under 200.
Do not eat or drink fluids, except water for 6 hours prior to the test.
You may take your regularly scheduled non-diabetes medications if tolerated on an empty stomach.
Check in 15 minutes prior to your appointment at the main registration desk.
- Bring your insurance card.
- Wear warm, loose, comfortable clothing with no metal.
- Do not chew gum.
- Do not wear any jewelry.
- No exercise prior.
Okay to take on the day of
- Continue usual Lantus or Levemir insulin dose.
- Continue usual basal insulin if you wear an insulin pump. DO NOT give any boluses.
DO NOT take on the day of until After your scan
- Sulfonylureas: Amaryl chlorpropamide, Diabeta, glimepiride, glipizide, glipizide ER, glipizide XL, Glucotrol, Glucotrol XL, glyburide, Glynase, tolazamide, tolbutamide
- SGLT-2 Inhibitors: canagliglozin, dapagliflozin, empagliflozin, Farxiga, Invokana, Jardiance
- Meglitinides: nateglinide, Prandin, repaglinide, Starlix
- Amylin Analog: SymlinPen, pramlintide
- Biguanides (metformin): Fortamet, Glucophage, Glucophage XR, Glumetza, metformin, metformin ER, Riomet
- Thiazolidinediones: Actos, Avandia, pioglitazone, rosiglitazone
- DPP-4 Inhibitors: alogliptin, Januvia, linagliptin, Nesina, Onglyza, saxagliptin, sitagliptin, Trajenta
- GLP-1 Agonists: albiglutide, Bydureon, Byetta, dulaglutide, exenatide, exenatide ER, liraglutide, Tanzeum, Trulicity, Victoza
- Combinations: Actoplus Met (pioglitazone/metformin), Actoplus Met XR (pioglitazone/metformin ER), Duetact (pioglitazone/glimepiride), Glucovance (glyburide/metformin), Glyxambi (empagliflozin/linagliptin), Invokamet (canagliflozin/metformin), Janumet (sitagliptin/metformin), Jentadueto (linagliptin/metformin), Juvisync (sitagliptin/simvastatin), Kazano (alogliptin/metformin), Kombiglyze XR (saxagliptin/metformin ER), Metaglip (glipizide/metformin), Oseni (alogliptin/pioglitazone), PrandiMet (repaglinide/metformin), Synjardy (empagliflozin/metformin), Xigduo XR (dapagliflozin/metformin)
- Miscellaneous: acarbose, colesevelam, Glyset, miglitol, Precose, Welchol
- Meal-time Insulins: Apidra, Humalog, Humulin R, Novolin R, NovoLog
- Insulin NPH, U500, and Combinations: NPH (N), 70/30, 75/25, 50/50, U500
- Call your diabetes provider if you have questions.
After the PET scan
You may resume all diabetes medications and normal activity. Drink plenty of water to expedite the FDG leaving your body.
Our radiologist will study your examination and a report will be forwarded to your practitioner, from whom you may obtain the results. If you have any questions regarding this procedure, please contact our department at at 608-342-4740.
Date of appointment _______________________________________ Time_____________________
Your procedure will be performed at Southwest Health at 1400 Eastside Road – Platteville, WI 53818. Please use the Main Hospital Entrance and check in at the Registration Desk prior to your scheduled procedure.
If you cannot keep your appointment please contact the radiology department at 608-342-4740 so that me may accommodate another patient.
NOTE: It may take 2-3 days to obtain verification from your insurance company for exams that require prior authorization, such as CT, MRI, Nuclear Stress, Injections, etc.