PET/CT scan is a type of procedure that makes use of images from two technologies in determining the exact location of an abnormality in the body and consequently, detecting diseases such as cancer and other abnormalities.

Positron emission tomography (PET) uses controlled amounts of a radioactive substance, called a radiotracer, in measuring cell activity in an organ or tissue.

Computed tomography (CT) imaging uses special x-ray equipment to produce multiple images or pictures of the inside of the body. CT imaging provides excellent anatomic information.

By combining information about the body’s anatomy and metabolic function, a PET/CT scan provides a more detailed picture of cancerous tissues than either test does alone. The images are captured in a single scan, which provides a high level of accuracy.

Aside from detection, a PET/CT scan can also determine whether the disease has spread to other parts of the body. It can also evaluate the effectiveness of a cancer treatment plan or determine if the disease has returned after treatment.

What To Expect: PET CT

More information and instructions for this procedure.

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How It Works

PET/CT scanning works by first using radiotracers. These are molecules that are linked to small amounts of radioactive material detectable on the PET scan.  Radiotracer accumulates in cancerous tumors as well in the areas of inflammation. F-18 fluorodeoxyglucose or FDG is the most commonly-used radiotracer; a molecule similar to glucose.  Cancer cells absorb glucose at a higher rate which can be detected on PET/CT scans.

The radiotracer is injected into the body through intravenous access or port. It will accumulate in the area of the body that is subject to examination. The radiotracer’s emissions are detected by a PET/CT scanner which produces images and provides molecular information.  Those images are then reconstructed using a PET algorithms to produce detailed slices offering insights of the structure and function of organs and tissues in the body.

During The Test

PET/CAT scanning is a non-invasive procedure that can take up to two hours.  It is typically undertaken on an outpatient basis.

The test begins by obtaining blood sugar level to ensure it is within PET scan parameters. Nursing staff will place a small needle into a vein, usually in your arm or the back of your hand, to fit an intravenous line (a thin plastic tube) through which the liquid radioactive material is injected. If needed Port-A-Cath can be accessed. You will be asked to rest quietly on a recliner, avoiding movement or talking for approximately one hour.  During this time you will be alone.

The patient will be instructed to empty their bladder to improve image quality. You will then be moved to the scanning room and positioned on the PET scanning bed. The CT scan is done first and takes less than 2 minutes. The PET scan takes approximately 25 minutes, but the time will vary depending on the areas of your body being scanned.

The intravenous line will be removed before you leave. You should drink plenty of fluids after the test is finished. This will flush the radioactive substance out of the body through the kidneys and into the bladder.


If you have had a prior PET/CT and or CT scan at another facility, you must bring a copy of that disc or discs. Please notify your physician if you are claustrophobic or pregnant. Plan to be in the PET/CT department for approximately 2 to 3hrs and please note that we advise patients to stay away from children and pregnant women for 6 to 24 hours following the time of injection. We are extremely cautious in this regard; there are NO definite risks from this level of radiation.

Please wear comfortable and warm clothing to the exam and do not wear jewelry or clothes with any metal buttons, underwire bra, or metal zippers.

Diabetic Patients:

  • Insulin Controlled Diabetes: Have a meal with your insulin 4 hours prior to your appointment
  • Non-Insulin Controlled Diabetes:
    • If you have a morning PET/CT appointment, please do not take your diabetic tablets on the morning of your scan but bring them with you so that you can take them immediately after your scan has been completed.
    • If you have an afternoon PET/CT appointment, please take your diabetic tablets on the morning of your scan, not less than 6 hours before the time of your appointment.

PET/CT Diet Plan:

24 Hours before your exam –

  • No caffeine
  • No exercise or participate in strenuous physical activity

6 Hours before your exam –

  • Do NOT eat(including tube feeding)
  • Do NOT chew gum or cough drops, etc
  • Drink ONLY water without additives
  • No smoking
  • Take all prescribed non-diabetic medications.

Suggested Foods:

  • Protein: non-breaded beef, chicken, turkey, fish, pork, lamb, ham (without honey), hot dogs, lunch meats, shellfish, crab, peanut butter (1 or 2 servings total), most nuts, sunflower seeds (2 ounces total) and eggs.
  • Dairy: Low-fat cottage cheese, cheese, x serving light yogurt with artificial sweetener (Dannon light or Yoplait light), sour cream, butter, half and half.
  • Vegetables: Green beans, asparagus, broccoli, cabbage, cauliflower, celery, cucumber, lettuce, mushrooms, radishes, spinach and zucchini.
  • Condiments: Mayonnaise, salad dressing and barbecue sauce (those with 3g carbohydrates or less per serving), oil, vinegar, mustard, hot sauce, tartar sauce, olives, dill pickles.
  • Beverages: Diet soda, water, sugar free Crystal Light, milk.

*For a snack, try celery with peanut butter, light yogurt or cottage cheese

Foods To Avoid:

All foods containing sugar & most processed foods, even “low carb” items.

  • Fruits & Vegetables: All fruits, potatoes, corn, carrots, legumes (beans), tomatoes, peas, squash, “veggie burgers”.
  • Breads & Grains: All types of grains, rice, breaded foods, pasta/noodles, rice cakes, crackers.
  • Beverages: Beer, wine, liquor, juices.
  • Snack Foods: Chips, pretzels, candy, gum, cough drops, breath mints.
  • Other: Syrups, jams, ketchup, sauces and gravies.

Menu Suggestions:

  • Breakfast: *Bacon/Sausage and eggs *Ham and cheese omelet *Veggie and cheese omelet *Light yogurt
  • Lunch: *Egg salad *Chef salad (no tomato) *Ham & Cheese wrapped in lettuce *Cottage cheese
  • Dinner: *Veggie/Meat soup made with canned broth *Cheeseburger (no bun) *Chicken with Barbeque sauce

Type Of Scans:


This procedure uses fluorodeoxyglucose (FDG) molecules in detecting active malignant lesions like colorectal cancer, breast cancer, lung cancer, lymphoma, melanoma, and multiple myeloma. It can also be relied upon in monitoring response to therapy of a malignant disease.


Our mission at NY Imaging Specialists is to provide the highest-quality advanced imaging in a patient-centered and compassionate environment, with the comfort and convenience of being close to home.

To schedule an appointment by phone call 833-269-4624.