Nuclear cardiac imaging uses radioactive substances called tracers to diagnose and treat cardiac conditions with greater precision and accuracy. At the University of Miami Health System in South Florida, this advanced imaging method is an important part of our comprehensive cardiac services.

Nuclear cardiac imaging includes two key tests — positron emission tomography (PET) and single-photon emission computerized tomography (SPECT).

How do cardiac PET and SPECT scans work?

Cardiac PET and SPECT scans are noninvasive and require no surgery.

We perform these tests by injecting a substance called a tracer into your bloodstream. The tracer contains a small amount of radioactive material that we then trace using special equipment. This provides three-dimensional images of the heart from all different angles.

PET and SPECT scans can:

• Provide highly detailed information about how blood flows through your heart and body.
• Help us find and diagnose cardiac problems earlier – sometimes even before symptoms develop.
• Support treatments to regenerate damaged heart muscle and improve heart attack outcomes.

Why might I need a PET or SPECT scan?

The 3D images from PET and SPECT scans can help diagnose conditions like:

• Heart damage from a heart attack or other causes.
• Coronary artery disease, including plaque buildup in the arteries.
• Heart infections.
• Heart disease such as cardiomyopathy.

We may also perform these scans to:

• Decide on a heart treatment plan, such as stenting or coronary artery bypass surgery.
• Assess how healthy your heart is before you have a medical procedure.
• Find out how certain heart treatments are working.

What’s the difference between a PET scan and a SPECT scan?

Both PET scans and SPECT scans provide powerful, detailed images. However, PET scans provide the highest level of detail and quality.

Also, radioactive tracers are different for each test. SPECT tracers emit gamma rays. PET tracers emit small particles called positrons.

How do I prepare for a PET or SPECT scan?

We’ll explain what to expect and how to prepare. For example, generally you’ll need to:

• Fast (not eat or drink) for several hours before your test, except you can have water.
• Possibly make other dietary adjustments, depending on what we’re testing for.
• Tell us about any medications you’re taking, including heart disease or diabetes medications.
• Stop using tobacco products on the day of your test.
• Avoid vigorous exercise for 24 hours before your test. Light, routine exercise is okay.
• Tell us if you have a fear of enclosed spaces. If so, we can talk with you about prescribing a mild sedative to help you feel more at ease during the scan.

What happens during a PET and SPECT scan?

Your appointment may take several hours in all. However, the actual scanning portion of the appointment usually only takes about 30 minutes. During your appointment:

• We’ll attach small patches to your body with wires that connect to an electrocardiogram machine (EKG). This will monitor your heart’s electrical activity during the test.
• We’ll place an IV line into your arm to administer the tracer for the test. You may feel a cold sensation when the tracer goes into your bloodstream.
• You’ll lie on a padded table that slides into the scanner, which looks like a large donut.
• You’ll need to stay very still during the scan. This helps us to obtain clearer images. You’ll hear buzzing and clicking, which is normal. This is the machine doing its job.
• We’ll remove the IV and disconnect the EKG machine when the scan is done. You can expect to go home shortly after that.

What is a nuclear cardiac stress test?

A nuclear cardiac stress test shows how your heart functions under stress (or exercise). Your doctor may include this with your PET or SPECT scan.

We do this by either:

• Asking you to exercise on a stationary bike or treadmill to increase your heart rate or
• Giving you medication that makes your body feel like it is exercising

How is a PET or SPECT stress test different from a regular stress test?

All of these tests show your heart’s electrical activity during exercise. However, PET and SPECT stress tests also provide more detailed information, including images of the blood flow in and around your heart.

What are the risks and side effects of a PET or SPECT scan?

PET and SPECT scans are safe for most people, and the radioactive material quickly passes out of the body. However, if you are pregnant or nursing, these tests could harm your baby. Be sure to tell us if you are nursing, pregnant, or think you may be pregnant.

Also, in rare cases, people may have a reaction or side effect to the tracer. If this happens, it’s usually mild and we can treat it. When a medication is used to simulate exercise for the test, there is a very slight chance of an adverse reaction to the medication.

We’ll talk with you in advance about any potential risks or side effects and the best way to address them. Our team is committed to ensuring the safest experience possible.

Why Choose UHealth?

Better, more precise diagnostic heart care and treatment. The better we understand your condition, the better we can treat it. Our advanced imaging services like PET and SPECT scans can help us identify problems with your heart and the best way to treat them. We’re experts at knowing which tests to offer, how to read them, and how to provide care and treatment tailored for you.

Advanced heart attack care and treatment. Having access to advanced imaging like PET and SPECT scans can support heart attack treatment and may even help restore damaged heart muscle. By showing blood flow to the heart, nuclear images can help determine if damaged heart tissue can benefit from advanced cardiac treatments.

Skilled multidisciplinary cardiovascular team. Our skilled providers are backed by a highly trained team of cardiac specialists to support you every step of the way in your diagnosis and treatment. We collaborate to create a personalized care plan and ensure the best possible treatment strategy.

Artificial-intelligence-powered imaging. As an academic medical center, we’re pioneering new ways to use artificial intelligence (AI) to help us achieve faster, better diagnoses. We’re also using AI to plan for complex procedures and train care providers on the latest techniques in cardiac care. This promises to support better outcomes and peace of mind for patients in the treatment of heart disease.

New cardiac technology center in South Florida. To further research and development into new innovations, we recently opened the Center for Digital Cardiovascular Innovations at our Miller School of Medicine. This unites researchers and others to discover the next technologies in heart medicine and bring them here for you.