PET/CT Scan
What is a PET/CT Scan?
In one continuous full-body scan (usually about 30 minutes), PET captures images of miniscule changes in the body's metabolism caused by the growth of abnormal cells, while CT images simultaneously allow physicians to pinpoint the exact location, size and shape of the diseased tissue or tumor.
Essentially, small lesions or tumors are detected with PET and then precisely located with CT.
Positron Emission Tomography (PET) and Computerized Tomography (CT) are both standard imaging tools that allow physicians to pinpoint the location of cancer within the body before making treatment recommendations.
The highly sensitive PET scan detects the metabolic signal of actively growing cancer cells in the body and the CT scan provides a detailed picture of the internal anatomy that reveals the location, size and shape of abnormal cancerous growths.
Benefits of PET/CT?
There are tremendous benefits of having a combined PET/CT scan:- Earlier diagnosis
- Accurate staging and localization
- Precise treatment and monitoring
With the high-tech images that the PET/CT scanner provides, patients may be able to avoid other unnecessary procedures. A PET/CT image also provides early detection of the recurrence of cancer, revealing tumors that might otherwise be obscured by scar tissue that results from surgery and radiation therapy, particularly in the head and neck.
In the past, difficulties arose from trying to interpret the results of a CT scan done at a different time and location than a PET scan, due to the fact that the patient's body position had changed. The combination PET/CT provides physicians a more complete picture of what is occurring in the body - both anatomically and metabolically - at the same time.
What Should I Expect?
Difficult questions deserve answers, and taking a "wait and see" approach is sometimes unacceptable. A PET scan helps answer those tough questions.
Your PET scan will produce a "picture" of how your body's cells are functioning, whereas an x-ray, CT scan, or MRI produce a picture of bones, organs and tissues.
Your PET scan will help you and your physician make a more informed decision about your diagnosis and treatment path.
Some hints to prepare you for your scan:
- Dress comfortably and warmly. Scanner rooms can sometimes be cool.
- Avoid eating anything for at least six hours before your scan (this includes sugar-free gum, mints, candy and beverages other than water).
- No strenuous exercise the day of your exam (example: working out, jogging, etc.).
- Please bring a copy of your most recent CT, X-Ray, or MRI films with you on the day of your PET scan if available.
- Be prepared to sit quietly for at least one hour after being injected with the radioactive dose.
- Drink lots of water the day before and after your exam.
Procedure
A PET scan is completely painless and has no side effects. After fasting for 6 hours, you will receive an injection of a trace amount of radioactive glucose, which is distributed throughout the body.
About 60-90 minutes after the injection, you will be asked to empty your bladder. Images will then be taken of your body as you lie still on the scanner bed.
How Long Will the Scan Take?
Please allow 21/2 to 3 hours for your appointment. This time includes pre-injection prep time, post injection resting period to allow proper uptake of the injection into the cells of your body, and actual scan time on the PET scanner. The results are then interpreted by a trained nuclear medicine physician or radiologist and sent to your referring physician.
Diabetics
If you are diabetic, please call the facility for special instructions
After My PET Scan
When the PET scan is done, make sure to drink plenty of water or other fluids throughout the day.
Results of My PET Scan
Your PET scan results will be reported to your referring physician within 1-2 business days. Please contact your physician to discuss your PET scan results.
Patient Preparation
Diet
Non-diabetic patients NO sweets (desserts/candy/sodas). Limit carbohydrates (bread, pasta, potatoes, and tortillas) the day before your exam. Drink water. High protein meals are encouraged.
Fasting
For morning appointments scheduled between 8:00 - 11:00am do not eat anything after midnight, but drink water. For afternoon appointments scheduled between 1:00 and 3:00pm., you may not eat after 7:00am. Make sure it is high protein (No carbs, sugar, coffee, gum, bread, mints, cough drops, cough syrup, cereal, etc.) DRINK WATER ONLY.
Medications
You may take your prescription medications with water only. NO antacids (Rolaids/Tums), multi-vitamins, cough drops or elixirs (cough syrup), gum, mints, or candy the day of your exam.
Diabetics
If you are diabetic, please call the facility for special instructions
Exercise
You should not perform any strenuous exercise the day before or the day of the study. (example: cutting down trees/mopping floor, etc)
Prior Imaging Studies
We will arrange to have your prior imaging studies sent to us (e.g. CT scans, bone scans, x-rays, MRI scans, etc.) so that we can compare these to your PET/CT scan. Contact us if you have had any recent studies your doctor is not aware of so that we may obtain these studies prior to your exam.
Appointment
Please be on time for your appointment. The injection that we give you has a very short shelf life and is very expensive. If you need to reschedule please call us 24 hours in advanced so that we may cancel your dose.
Sedation
Claustrophobic patients should consult with their primary care physician in order to obtain a mild anti-anxiety to bring with them to take prior to the scan. Transportation should be arranged according to medication instructions.
Clothing
Wear loose warm clothing and no jewelry. We recommend that women wear a two-piece outfit.
Children
Children are not allowed to accompany you on the day of your exam.
What to Expect
An IV will be placed in your vein so that we can administer an injection of F-18 FDG (fluorodeoxyglucose) which is a sugar-based solution with a short-lived radioactive isotope. Following this injection, you will wait 60 to 90 minutes to allow the isotope to be distributed throughout your body. FDG is taken up by all the cells in the body. However, more abnormally active cells (e.g. tumors) take up a greater percentage of the FDG than normally active cells. These cells present as "hot spots" on the images. After the 60 to 90 minutes wait period you will be escorted to the PET/CT scanner for imaging. You will be lying still on the scanner table for 30-45 minutes. Melanoma patients will be lying still on the scanner table for approximately 1 hour.
Post Procedure Instructions
Following the study you may eat and resume your normal activities/diet. Fluid is encouraged to promote excretion of the FDG. Because there is a minimal amount of radiation remaining in your body for 6-8 hours following the exam it is recommended that you avoid close contact with children and pregnant women.