Multigated acquisition (MUGA) scan
A multigated acquisition (MUGA) scan is a nuclear medicine imaging test that checks how well the heart is pumping during rest or exercise. A MugA scan uses a radioactive material (radiopharmaceutical) that targets the heart, along with a gamma camera and a computer, to create images of the blood flowing through the heart.
A MUGA scan is also called nuclear ventriculography, radionuclide angiography or cardiac blood pool scan.
Why a MUGA scan is done
A MUGA scan may be done to:
- check how well the heart is pumping
- evaluate the size of the heart chambers
- check the pumping action of the lower ventricles
- find any abnormalities in the muscle walls of the ventricles
- see any abnormal movement of blood between chambers
- track the effect of certain kinds of chemotherapy drugs on the heart to make sure it is safe to continue with chemotherapy
- follow up and monitor the late side effects of cancer treatment
How a MUGA scan is done
A MUGA scan is usually done as an outpatient procedure in the nuclear medicine department of a hospital. This means that you don’t stay overnight. The test takes about 1 hour, but it may take longer if the test includes exercise.
Before you have any nuclear medicine test, it is important to tell the nuclear medicine staff if you are breastfeeding or pregnant or think you may be pregnant.
Tell the staff if you have recently had other nuclear medicine tests, such as a bone or thyroid scan.
You may be told to:
- not eat or drink for 4 to 6 hours before the test, especially if the test includes exercise
- avoid caffeine and tobacco for 24 hours before the scan
- bring a list of medicines you are taking and the date of your most recent chemotherapy treatment
You may be told to not wear clothes with metal zippers, belts or buttons on the day of the scan. Or you may change into a gown for the test. If you are wearing glasses, jewellery or objects that could interfere with the test, you will be asked to take them off.
The doctor will ask you about your history of heart disease and which tests or procedures you have had done on the heart.
The technician will take a blood sample to mix with the radioactive material. Then the mixture gets injected back into your vein.
You will have small pads or electrodes stuck to the skin of your chest. These monitor your heart rhythm and match up the images with your heartbeat.
A gamma camera detects radiation given off by the radioactive material in the heart’s cells and tissues. It takes pictures of the radiation and sends them to a computer. It is important to stay still while the camera is taking pictures. You may need to change position so the camera can take pictures from different angles. In between pictures, you may be asked to walk on a treadmill or use a stationary bike to see how your heart responds to the stress of exercise (stress MUGA).
After a MUGA scan
The radioactive material passes out of the body through urine or stool (feces). It may take a few hours or days to completely pass out of your body. Drink lots of fluids after the test to help flush it out.
The dose of x-rays or radioactive materials used in nuclear medicine imaging can be different for every test. The dose depends on the type of procedure and body part being examined. In general, the dose of radioactive material given is small and you are exposed to low levels of radiation during the test. The benefits of having a MUGA scan outweigh the risk of exposure to the small amount of radiation received during the scan.
Allergic reactions to the radioactive material may occur, but they are extremely rare.
What the results mean
A MUGA scan shows how well your heart is pumping blood to the rest of your body (your heart’s squeezing strength). You will see it as a percentage.
What happens if the results are abnormal
Your doctor may recommend more tests, procedures, follow-up care or treatment.
Special considerations for children
Preparing children before a test or procedure can help lower their anxiety, increase their cooperation and develop their coping skills. This includes explaining to children what will happen during the test, such as what they will see, feel and hear.
Preparing a child for a MUGA scan depends on the age and experience of the child. Find out more about helping your child cope with tests and treatments.
The use of radioisotopes to diagnose and treat disease.
Radioisotopes can be given through injection into a vein (IV), by mouth or through a catheter.