PET Scan

PET SCAN PATIENT INFORMATION AND PREPARATION GUIDELINES

There are 2 types of PET scans. You will be having either a Whole Body or a Brain PET. The preparation is the same for both procedures. The difference between the 2 exams is the amount of time involved. The Whole Body PET scan, including injection and rest period is between 2 1⁄2 to 3 1⁄2 hours. The total time for a Brain PET is approximately 2 hours.

Please inform the staff member scheduling your appointment if you have any special needs such as assistance walking, use of a wheelchair, oxygen, etc.

For both types of PET scans, you must have absolutely nothing to eat or drink except water for 7 hours prior to your appointment time. This means no cough drops, chewing gum, hard candy, breath mints, etc. Please stop drinking water 2 hours before your appointment.

You should take your prescription medication as required with the smallest possible amount of water only if it must be taken during the few hours prior to your PET scan. Avoid strenuous exercise or vigorous physical activity for 24 hours prior to your PET scan.

Bring with you a list of medications that you are currently taking (prescription and others such as vitamins, herbs, etc.) It is also important to have a written list of prior surgeries and their dates, and the last date of radiation therapy or chemotherapy if you have ever had any. This information is necessary for the accurate interpretation of your scan.

It is extremely important that you bring with you copies of reports and films of any prior PET scans not done at our facility as well as any CT scans or MRI's done in the last 6 months. If you have had more than one, you should bring the most recent, as well as all the reports. If you cannot personally bring the outside films and reports, please arrange to have them sent by your doctor’s office. Without these comparison studies, your PET scan results will be delayed and possibly incomplete.

PREMEDICATION
In specific instances, Valium will be ordered for you to take prior to your PET scan injection. This is not given for sedation, but rather as a muscle relaxer to minimize uptake of the radioactive tracer in the neck, shoulder and other muscles. We do not stock or administer Valium or other pre-medication for PET scans at our facility. If it is indicated for your exam, your physician will have given you a prescription for a single dose of Valium, which may be filled at your local pharmacy. You should bring it with you at the time of your appointment. Do not take the medication until instructed to do so by the technologist. There is a specific interval between the dose of Valium and the injection time for your scan. If taken too early or too late, the desired effect will not be achieved.

FOR DIABETIC PATIENTS ONLY
It is extremely important that your blood sugar be as close to normal as possible when having a PET scan. Optimally, it should be below 135. If it is above 200, your PET scan may need to be rescheduled.
Check the following instructions with your doctor prior to your PET scan appointment date:
For patients on ORAL blood sugar medicine, take your medication as usual. Do not eat, but bring a snack with you in case your blood sugar drops rapidly.
For patients on INSULIN, do not take any within 4 hours of your PET scan appointment time. Do not eat, but bring your insulin and a snack with you.
If your blood sugar is controlled solely by DIET, follow your usual eating plan until 7 hours before your PET scan appointment. Do, however, try to avoid foods high in carbohydrates the night before your scan.
In all cases, please check your blood sugar the morning of your PET scan appointment and let the technologist know the results. We may also measure your blood sugar with a "finger stick" prior to beginning your PET scan. If you have any questions about your medication, please check with your physician.

WHEN YOU ARRIVE
If you bring outside films and reports, give them to the receptionist at this time. We will need to copy the reports and hold on to the films until the PET scan is read. Your outside study will be returned to your physician with the PET scan films and report. If other arrangements must be made regarding outside studies, please inform the technologist at the time of your scan.

After you have been checked in, the technologist will bring you to the PET scan suite. You will be asked to fill out and sign a screening form that covers your medical history, symptoms, weight, scan history, etc. The PET scan procedure will be explained in detail at this time. Once this is completed, you will be asked to sit in the “Rest Area” so that our IV nurse may start the injection process. A catheter (small flexible needle) is inserted in a vein. You will then be given the radioactive tracer through this I.V. immediately after injection, you must rest completely, with no physical activity. You may not read, walk around or speak unnecessarily during this period, which lasts from 60 to 80 minutes.

The reason for this is as follows: The radioactive material you will be injected with contains a minute amount of “glucose” or sugar (18Flurodeoxyglucose). It is taken up by all the tissues in the body including muscle. Any physical activity will cause an increase in uptake of this material where it is undesirable. This may cause a decrease in scan quality and make it difficult to interpret the images. For example, speaking after the dose is injected may result in marked vocal cord uptake. Holding a book may cause increased arm and neck muscle uptake. All of these things will detract from your scan. Following the rest time, the catheter will be removed from your vein. The technologist will encourage you to use the bathroom at this point. It is very important that your bladder be empty for your WHOLE BODY PET scan. Even a partially full bladder can detract from you images. You will leave your clothing on for the scan, but will be asked to remove large metal objects from pockets (coins, keys, etc.). You will need to remove your jewelry as well, so it is best left at home if possible. At this point, your scan will begin. The technologist will explain positioning and demonstrate what will be required of you during the scan. Basically, you will be lying very still for approximately one hour. The exact scan time will be determined once you are on the imaging table. The most important factor in getting a good PET scan is moving as little as possible throughout the exam. The technologist will remain in the room with you during imaging. Once your scan is completed, you may leave or go on to have any other scheduled exams.