Nuclear Medicine

You should avoid caffeine (caffeinated as well as decaffeinated coffee, hot and cold tea, caffeinated soft drinks and energy drinks, etc.) and smoking for up to 48 hours before your examination. Your physician may give you more specific instructions.

You should not eat or drink anything after midnight on the day of your procedure, but you may continue taking medications with small amounts of water unless your physician says otherwise. If you take beta-blocker medication (Inderal, metoprolol, etc.) you should specifically ask your physician about temporary discontinuation.

In order to evaluate the coronary arteries, heart scans are often performed immediately after patients have engaged in physical exercise (called a stress test) so that blood flow throughout the heart is maximized, making any blockages of the coronary arteries easier to detect. These images of the heart are compared with heart images taken while the patient is at rest. Patients who are unable to exercise are given a drug that increases blood flow to the heart.

You will be asked to exercise until you are either too tired to continue or short of breath, or if you experience chest pain, leg pain, or other discomfort that causes you to want to stop.

If you are given a medication to increase blood flow because you are unable to exercise, the medication may induce a brief period of feeling anxious, dizzy, nauseous, shaky or short of breath. Mild chest discomfort may also occur. Any symptoms that do develop typically resolve as soon as the infusion is complete. In rare instances, if the side effects of the medication are severe or make you too uncomfortable, other drugs can be given to stop the effects.

The exam will usually begin with an injection of tracer while you are resting. Approximately 60 minutes after the tracer is injected, you will lie on a moveable imaging table with your arms (or in some cases your left arm only) over your head for about 15 to 20 minutes while images are recorded. Following imaging, you will undergo a stress test, which requires you to exercise by walking on a treadmill for a few minutes.

While you exercise, the electrical activity of your heart will be monitored by electrocardiography (ECG) and your blood pressure will be frequently measured. When blood flow to the heart has reached its peak, you will be given the radiotracer through your IV. Approximately 60 minutes later you will be placed on the imaging table a second time so a second series of images can be recorded. At this time, an ECG will also be placed to image the motion of your heart.

Actual scanning time for each heart scan varies from 15 to 30 minutes. Total time in the nuclear medicine department will be approximately two to four hours.

A CT scan of your heart may be obtained before or after each of the nuclear medicine imaging procedures. You will not have to get up or change positions on the table for this part of the exam as the CT is part of the nuclear medicine equipment, but you will be asked to stay very still for this portion of the exam.

Through the natural process of radioactive decay, the small amount of radiotracer in your body will lose its radioactivity over time. It may also pass out of your body through your urine or stool during the first few hours or days following the test. You should also drink plenty of water to help flush the radioactive material out of your body as instructed by the nuclear medicine technologist.

A radiologist will interpret the images and forward a report to your referring physician.  

You may be asked to wear a gown during the exam or you may be allowed to wear your own clothing depending on the test.

Jewelry and other metallic accessories should be left at home if possible, or removed prior to the exam because they may interfere with the procedure.

You should receive specific instructions from the ordering physician based on the type of scan you are undergoing.

You will be positioned on an examination table. If necessary, a nurse or technologist will insert an intravenous (IV) catheter into a vein in your hand or arm. The radiotracer is then injected intravenously, swallowed or inhaled as a gas. It can take anywhere from several seconds to several days for the radiotracer to travel through your body and accumulate in the organ or area being studied.

When it is time for the imaging to begin, the camera or scanner will take a series of images. The camera may rotate around you or it may stay in one position and you will be asked to change positions in between images. While the camera is taking pictures, you will need to remain still for brief periods of time. In some cases, the camera may move very close to your body. This is necessary to obtain the best quality images. If you are claustrophobic, you should inform the technologist before your exam begins.

If a probe is used, this small hand-held device will be passed over the area of the body being studied to measure levels of radioactivity. The length of time for nuclear medicine procedures varies greatly, depending on the type of exam. Actual scanning time can take from 20 minutes to several hours and may be conducted over several days.

When the examination is completed, you may be asked to wait until the technologist checks the images in case additional images are needed. Occasionally, more images are obtained for clarification or better visualization of certain areas or structures. The need for additional images does not necessarily mean there was a problem with the exam or that something abnormal was found, and should not be a cause of concern for you.

Except for intravenous injections, most nuclear medicine procedures are painless. When the radioactive material is injected into your arm, you may feel a cold sensation moving up your arm, but there are generally no other side effects.

When swallowed, the radiotracer has little or no taste. When inhaled, you should feel no differently than when breathing room air or holding your breath.  

Unless your physician tells you otherwise, you may resume your normal activities after your nuclear medicine scan. If any special instructions are necessary, you will be informed by a technologist, nurse or physician before you leave the nuclear medicine department.

Through the natural process of radioactive decay, the small amount of radiotracer in your body will lose its radioactivity over time. It may also pass out of your body through your urine or stool during the first few hours or days following the test. You should also drink plenty of water to help flush the radioactive material out of your body as instructed by the nuclear medicine technologist.

You will be informed as to how often and when you will need to return to the nuclear medicine department for further procedures.