Nuclear Imaging

Treating Cardiovascular Diseases in Wisconsin and Northern Illinois

Nuclear imagingis a diagnostic procedure that uses small amounts of radioactive material to produce images of various body parts. When nuclear imagingis used to diagnose heart disease, it is called cardiac imagingor nuclear heart scanning. Except for the IV used for injecting the radioactive material, cardiac nuclear imagingis noninvasive, meaning it doesn’t require surgery or the insertion of a catheter.

Unlike MRI and CT scans, which provide only structural information, cardiac nuclear imagingprovides information on how well your heart is functioning. Without cardiac imaging, your doctor may need to perform invasive tests or surgery to obtain this information.

Doctors use cardiac nuclear imaging for three main purposes:

  • To check for damage to your heart muscle
  • To see how well blood flows to your heart muscle
  • To see how well your heart pumps blood to your body 

How Does Cardiac Nuclear Imaging Work?

During cardiac imaging, a safe, radioactive substance called a tracer is injected into your bloodstream through a vein. The tracer travels to your heart where it releases energy known as gamma rays (similar to X-rays). Special gamma cameras outside your body detect this energy and use it to create pictures of your heart.

Nuclear imagingis sometimes described as inside-out X-rays. While traditional X-rays send radiation through your body, nuclear imagingrecords radiation that’s emitted from tracers inside your body.

Cardiac imaging is considered very safe. The amount of radiation exposure received during nuclear imaging is similar to the amount received during a routine chest X-ray or CT scan. (However, cardiac imaging is not recommended for women who are pregnant or breastfeeding.)

During cardiac imaging, your doctor is likely to monitor your heart rate and blood pressure. An electrocardiograph (EKG) will monitor your heart’s electrical activity. Your doctor may also take blood tests periodically to monitor hormone levels, electrolyte levels and/or red blood cell levels. 

Cardiac Imaging Provides Valuable information

The information provided fromcardiac nuclear imaginghelps your doctor:

  • Assess a patient’s condition after bypass surgery or angioplasty
  • Assess blood flow to the heart and detect atherosclerosis or coronary artery disease
  • Evaluate pumping function of the heart, which may indicate cardiomyopathy, heart injury or infection
  • Identify people at risk for a heart attack and assess their candidacy for angioplasty or bypass surgery
  • Monitor the effects of chemotherapy or medications on the heart
  • Visualize the size and location of a heart attack

Types of Cardiac Nuclear Imaging

There are several types of cardiac imagingand doctors have specific reasons for using each:

  • A hemodynamic test helps doctors determine the cause of certain circulation disorders, including syncope (fainting), which is caused by a temporary decrease in blood flow to the brain. This test often follows a tilt test.

    Your doctor will advise you on special preparations for this test. Most likely you will need 2 – 3 hours for your appointment. You may need to avoid caffeine 24 hours before the test and not eat or drink anything except water 4 hours before the test.
  • A multigated acquisition scan (also known as a MUGA scan) helps doctors evaluate the pumping function of the ventricles (the lower chambers of the heart). This test is also known as an equilibrium radionuclide angiogram or blood pool scan.

    Learn how to prepare for your MUGA scan (PDF, 54 KB). 
  • A nuclear adenosine stress test (also known as pharmacological nuclear stress test) is very similar to the nuclear exercise stress test (above). However, instead of exercising, your doctor will give you adenosine or a similar medication to dilate the blood vessels leading into your heart. This increases blood flow to simulate exercise. It does not increase your heart rate.

    Your doctor will advise you on special preparations for this test. Most likely, you will need 3 – 4 hours for this appointment. You may need to avoid caffeine for 24 hours before the test. On the day of the test, you may be asked to not smoke or eat or drink anything except for small sips of water to help swallow medications. Your doctor may also ask you to stop taking some heart medications on the day of the test.

    Learn how to prepare for drug-induced stress testing (PDF, 113 KB). 
  • A nuclear exercise stress test (also known as a myocardial perfusion stress test) helps doctors determine whether your heart receives adequate blood flow while you exercise. During this test, blood flow to your heart is first monitored while you rest and again as you exercise on a treadmill or stationary bike. The results of the two tests are then compared.

    Your doctor will advise you on special preparations for this test. Most likely you will need 3 ­­– 4 hours for this appointment. You may need to avoid caffeine for 24 hours before the test. On the day of the test, you may be asked to not smoke or eat or drink anything for 4 hours before the test except for small sips of water to help swallow medications. Your doctor may also ask you to stop taking some heart medications on the day of the test.
  • Positron emission tomography (also known as a PET scan) provides information about the blood supply to the heart muscle and the metabolic activity of the heart. It can also show blockages in coronary arteries, scarring from past heart attacks and help identify areas that have potential to recover with bypass surgery or angioplasty.

    Learn how to prepare for your PET scan (PDF, 99 KB).

Leading Midwest Cardiovascular Program

Aurora is known for providing one of the best cardiovascular programs in the United States. Our coordinated care includes access to outstanding doctors and services for preventing, diagnosing and treating heart conditions and disorders. We also offer a full-service rehab program to ensure your optimal recovery.

We also have the largest cardiac teaching program in Wisconsin, which puts us in a unique position to access the most recent technologies for diagnosing and treating heart disease.

Our doctors are conveniently located throughout eastern Wisconsin and northeastern Illinois. Find a doctor or heart specialist near you. To get a second opinion or if you need assistance finding a provider, please call 888-649-6892.