Nuclear medicine tests take pictures of the body after small amounts of radioactive material are ingested.
What are nuclear medicine tests?
For nuclear medicine tests, small amounts of radioactive material are injected, swallowed, or breathed in. Then, special cameras take pictures of the body from different angles. The cameras detect the radiation and take very detailed pictures of where the radioactive material goes in the body.
The amount of radioactive material used in the tests is very small and will not harm your child.
Several different nuclear medicine tests are used to help diagnose heart conditions:
- The stress MIBI test shows how the blood flows through your child's heart while your child relaxes and while your child is exercising.
- The MUGA scan checks how well your child's heart is pumping.
- The ventilation perfusion scan evaluates air flow and blood flow in the lungs.
Stress MIBI test
During the test, a small amount of radioactive material called MIBI is injected into your child’s blood. Then, special cameras take pictures of your child’s heart from different angles. The radioactive material lets the camera take very detailed pictures of how the blood flows through the heart.
The test has two parts:
- First your child’s heart is tested while your child relaxes.
- Then your child does an exercise test while we check blood flow.
Imaging for the test usually takes about 15 to 20 minutes for each part. However, it is likely that you and your child will be at the hospital all day.
Your child should sleep well and get a good breakfast before the test
These are the things your child should do to get ready for the test:
- Your child should get a good night’s sleep before the test.
- Your child should eat a good breakfast on the day of the test.
- Your child should not eat for at least 1 to 2 hours before the start of the test.
- Your child should wear or bring a T-shirt, shorts, and running shoes for the test.
- Your child should be prepared to exercise.
A nuclear medicine technologist gives the test
Nuclear medicine technologists are people who are trained to give the tests on the machines in the hospital. The exercise part of the test is given by two cardiology technologists as well as the nuclear medicine technologist.
The first part of the stress MIBI test: taking pictures of your child's heart at rest
The technologist will put a small intravenous (IV) tube into a vein in your child’s arm. Next, the technologist will put a small amount of radioactive medicine called MIBI into the IV tube.
It takes about 1 hour for the MIBI medicine to collect in your child’s heart muscle, so your child must now wait about 1 hour before the technologist can take the pictures. You can leave the department and the technologist will tell you what time to come back to have the pictures taken.
Your child will be asked to eat or drink something that has fat in it approximately half an hour after the MIBI injection. Examples of foods with fat in them are a muffin or a donut. You can also give your child 2% or whole milk. The fat contained in these foods helps to give a clear picture of your child’s chest and tummy.
When you bring your child back to the nuclear medicine lab, your child will lie down on a special bed. Then the nuclear medicine cameras will move around your child and take a set of pictures. This does not hurt, but your child will need to lie still for about 30 minutes.
After the pictures are done, your child can have a small lunch, such as soup and crackers, or a sandwich. Your child is then ready for the second part of the test.
The second part of the stress MIBI test: taking pictures of your child's heart during exercise
The second part of the stress MIBI includes an exercise test. Your child will need to walk on a treadmill, which is like a moving sidewalk, or ride a special bicycle.
Just before the test starts, a technologist will attach a long tube to your child’s IV. The tube is long so that it will reach your child while they are on the treadmill or bicycle. MIBI medicine will be put into the IV tube as your child is exercising, and the technologist will take pictures of the blood flowing to your child’s heart muscle.
When the exercise test is finished, your child will be asked to sit in a wheelchair. You and your child will go back to the nuclear medicine department to have the last set of pictures taken. This will take about 30 minutes. When the pictures are finished, the technologist will take out the IV tube. You can then take your child home.
After the test is over
Your child should drink lots of liquids, such as water, juice, or milk, during the rest of the day. This will help your child’s body get rid of the MIBI. Your child can eat as usual.
Getting the results of your child’s test
Your child’s cardiologist (heart doctor) will give you the test results within 10 to 14 days. If a problem is found during any of these tests, the technologist will tell your child’s cardiologist right away.
MUGA scan
A MUGA scan checks how well your child’s heart is pumping. MUGA is short for Multiple Gated Acquisition.
During a MUGA scan, a small amount of radioactive material is injected into your child's blood. This material can be seen very clearly with a special camera. The pictures taken by the camera show exactly how the blood is moving through your child’s heart.
MUGA scans take place in the Nuclear Medicine department of the hospital. A nuclear medicine technologist gives the test. The technologist is specially trained to give tests on the nuclear medicine machines in the hospital.
This test is done in 2 parts. It will take about 2 hours to complete.
Getting ready for a MUGA scan
To do a MUGA scan, your child needs to be able to stay still while the pictures are taken. If your child can lie quietly for about 30 minutes while we take the pictures, no preparation is needed. If your child cannot stay still that long, they may need to have sedation. When your child's scan is scheduled, ask the technologist when your child must stop eating and drinking.
First part of a MUGA scan: drawing blood
The first part of the scan will take about 30 minutes. The technologist will use a needle to take a small amount of blood from your child. Usually, the technologist will leave an intravenous (IV) tube taped to your child’s arm for the second part of the test. An IV is a narrow tube that gives liquids directly into your child's vein.
After the blood is taken, you and your child can leave the Nuclear Medicine room. The technologist will tell you what time to come back. While you are waiting, the technologist will mix a small amount of radioactive material into your child's blood for the second part of the test.
Second part of a MUGA test: putting blood and radioactive material back into the body
The second part of the MUGA test is usually 1 hour later.
The technologist will give your child’s own blood back through the IV tube or a needle. This blood has a small amount of radioactive material mixed into it. It is safe and will not make your child feel sick or dizzy.
The technologist will then attach 3 electrodes to your child’s chest. Electrodes are sticky pads that connect with wires to the electrocardiogram (ECG) machine. The ECG records your child’s heartbeat while the Nuclear Medicine camera is taking pictures of your child’s heart.
The test is safe and does not hurt. Your child will need to lie still for about 30 minutes.
After the MUGA scan
If your child was not given a sedative, they can eat and drink as usual. If your child was given a sedative for the test, they will need some time to become fully awake again. The nurse who gave the sedative will tell you what you need to do and how long that might take.
Getting the results of the MUGA scan
Your child’s cardiologist will give you the test results and tell you what they mean. It will be a few days before the doctor gets the test results.
Ventilation perfusion scan
A ventilation perfusion scan is a nuclear medicine test that uses radioactive material to evaluate air flow and blood flow in the lungs. This material is either breathed in or injected.