What is a rest-stress myocardial perfusion scan?
A rest-stress myocardial perfusion scan is obtained to evaluate blood flow to cardiac muscle during rest and stress conditions. The examination is done in two parts: a rest study and a stress study.
During the rest study, a radiopharmaceutical called Technetium-99m MIBI is injected into your child’s veins. Technetium-99m MIBI has a tiny amount of radioactive molecules in it. A special camera, called a gamma camera, is used to take pictures of the heart after the radiopharmaceutical has been injected.
During the stress study, electrodes will be placed on your child’s chest so that his or her heart rate can be monitored by an electrocardiogram (EKG). While your child is exercising, he or she will receive another injection of the radiopharmaceutical. Shortly after the injection, your child will stop exercising and additional images of the heart will be taken.
When might a rest-stress myocardial perfusion scan be needed?
A rest-stress myocardial perfusion scan can help assess:
- cardiac transplants
- Kawasaki's disease
- chest trauma
- tetralogy of Fallot repair
- anomalous left coronary artery
- autcome of an arterial switch operation
- Mustard or Senning operation
How should I prepare my child for a rest-stress myocardial perfusion scan?
- Your child should not have anything to eat or drink two hours prior to exam.
- Please check with your doctor about your child’s medications, as some medications may interfere with the accuracy of the test results.
- Your child should wear comfortable clothing for the exercise portion of the exam. This includes sneakers or running shoes because your child will be running on a treadmill/bike.
- It is helpful to give your child a simple explanation as to why the scan is needed and assure him or her that you will be there for the entire time.
- We have various DVDs to choose from for your child to watch during the scan or you can bring one from home.
What should I expect when I bring my child to the hospital for a rest-stress myocardial perfusion scan?
When you arrive, please go to the Nuclear Medicine check-in desk on the second floor of the main hospital. A clinical intake coordinator will check in your child and verify his or her registration information.
What happens during a rest-stress myocardial perfusion scan?
You will be greeted by one of our nuclear medicine technologists who will explain to you and your child what will happen during the examination. The technologist will place an IV catheter in one of your child’s veins that will remain in place throughout the entire procedure.
The examination is done in two parts:
- a rest study
- a stress study
- A tiny amount of the radiopharmaceutical will be injected through the IV.
- Thirty minutes later, imaging of the heart will begin. Imaging will take approximately 30 minutes.
- It is extremely important for your child to hold still to obtain the best quality images.
- When imaging is complete, the technologist will direct you to the stress laboratory in the Cardiology Department where the stress study is performed.
- A cardiology staff member will place small pads called electrodes on your child's chest. This will allow the exercise physiologist to perform an electrocardiogram (EKG) to monitor your child's heart rhythm during exercise.
- At peak heart rate, a nuclear medicine technologist will again inject the radiopharmaceutical through the IV.
- It is important that your child continue to exercise for an additional minute after the injection.
- Shortly afterwards, you and your child will return to the nuclear medicine department for the stress test imaging. The imaging takes 30 minutes.
- Again, it is extremely important for your child to hold still to obtain the best quality images.
The total time of the study is approximately three to five hours.
Will my child feel anything during a rest-stress myocardial perfusion scan?
Your child may experience some discomfort associated with the insertion of the intravenous needle. The needle used for the procedure is small. Once the radiopharmaceutical is injected and imaging is complete, the needle will be withdrawn and a gauze bandage with adhesive tape will be placed over the site of the injection. The area where the injection was given may be a little sore.
In addition, your child may feel the physical discomfort of the exercise. Although the gamma camera may appear large and intimidating, it does not touch your child.
Is a rest-stress myocardial perfusion scan safe?
We are committed to ensuring that your child receives the smallest radiation dose needed to obtain the desired result.
- Nuclear medicine has been used on babies and children for more than 40 years with no known adverse effects from the low doses employed.
- The radiopharmaceutical contains a very tiny amount of radioactive molecules. We believe that the benefit to your child’s health outweighs potential radiation risk.
- The camera used to obtain the images does not produce any radiation.
- It is safe to be in the room with your child if you are pregnant or nursing.
What happens after the rest-stress myocardial perfusion scan?
Once the scan is complete, the images will be evaluated for quality. If the scan is adequate, your child will be free to leave and resume normal activity.
One of the Boston Children's Hospital nuclear medicine physicians will review your child’s images and create a report of the findings and diagnosis.
How do I learn the results of the rest-stress myocardial perfusion scan?
The nuclear medicine physician will provide a report to the doctor who ordered your child’s rest-stress myocardial perfusion scan. Your child’s doctor will then discuss the results with you.