PET/CT Metabolic Evaluation/ Sarcoidosis Scan

Reviewed by Will Cook, ARRT, MA and Vicki LaRue, MIS, NMAA, Vicki LaRue, MIS, NMAA

What is a PET/CT Scan?

Your doctor has suggested you have a PET/CT scan of your heart as part of the evaluation at National Jewish Health. A PET scan is a shortened name for positron emission tomography. A PET scan views functioning tissues in the body. A CT or CAT scan is a shortened name for computerized tomography. A CT scan takes pictures of the inside of the body. The pictures are more detailed than a typical x-ray. The type of PET/CT scan your doctor recommended will show detailed images and functioning tissues of your heart.

The PET/CT scan can help determine if sarcoidosis has affected your heart. Your doctor will use this information to determine the best treatment for you.


How do you get ready for the test?

The accuracy of this test is dependent upon you following a very strict diet 24 hours prior to the scan. You must speak with the Nuclear Medicine Advanced Practitioner to go over the dietary restrictions. The only foods allowed the entire day before your scan include:

  • Plain meats: Grill or cook your own beef, chicken, or fish. Do not use any type of butter, oil or spray to cook meat in. Do not eat at a restaurant or go to a deli to get these meats. They must contain NO added spices, no sugar, no breading, etc. No processed meats such as bacon, hot dogs, deli meats such as bologna, flavored turkey/chicken, roast beef, or anything that has to be sliced from a meat case. These can have added sugar or ingredients that can cause your test to be nondiagnostic.

  • Eggs: Once again, cook eggs in nothing. Salt and pepper are permissible on eggs.

  • Raw or Salted Nuts: No flavored nuts such as smoked almonds, honey roasted peanuts, etc. Buy raw nuts from the bulk bins at a natural food store or eat Planters Roasted Peanuts. If it has a flavor, don’t eat it.

  • Beverages: Drink plain water or black coffee only. Add nothing to coffee. Do not buy water that has any type of flavoring. No added sweeteners. No sugar free sweeteners.

No over the counter medications. Items such as Tums, cough syrups, etc. contain sugar and must be avoided.

You must be fasting 12 hours prior to the scan. Only plain water is permissible after 7 pm the night before the test. Prescription medications may be taken. If you take medication for diabetes, you must speak with the Advanced Practitioner prior to taking these medications.


What is done during the test?

This test consists of two separate images of your heart. You will begin the day in the Cardiology Department located in the basement of the Smith building. Go to Cardiology as soon as you have checked in at the main admissions desk.

In Cardiology, a technologist will start an IV in a vein in your arm and inject a small amount of a radiotracer. This tracer evaluates the blood flow to your heart. The tracer needs to circulate for about 40 minutes. Afterward the technologist will position you on a camera that will take images of your heart. This scan is approximately 10 minutes long.

When this scan is complete you will be escorted to the PET/CT department. Here, a technologist will test your blood glucose level and give you a second injection of a radiotracer. This tracer will evaluate for inflammatory cells in your heart. This tracer needs to circulate in your system for about 60 minutes. During this time you will be in a private waiting room. You are to relax during this period. No reading, phone, or stimuli is allowed during this time. After about 60 minutes you will be moved to the PET/CT scanner. We will perform 1 or 2 scans depending on individual circumstances. These scans take about 10 minutes each.

The Nuclear Cardiology and PET/CT scans are easy to complete and do not cause pain. The test is lengthy, but simple.


What should you do after the test?

You can resume normal activities after the PET/CT scan.


How long will the test take?

The procedure takes about 3 hours.


How do you get to your test?

The first part of your test will be in the cardiology department. Go here right after checking in to the main desk inside the front door of the hospital. The second part of your test will be in the PET/CT area of the Medical Imaging department located on the 3rd floor of the Smith building.


This information has been approved by Will Cook, ARRT, MA and Vicki LaRue, MIS, NMAA (December 2016).