When it comes to heart health in children and teens, early and accurate diagnosis can be lifesaving. Many heart conditions in children can be identified with an exam, EKG or echocardiogram, but some situations require a more detailed look at the heart’s structure and function.
That’s when a cardiac MRI is used, such as when evaluating conditions linked to fainting, arrhythmias, congenital heart disease or rare causes of sudden cardiac death in young people.
Pediatric cardiology specialists use advanced cardiac imaging, including cardiac MRI, to help ensure children and adolescents receive the most precise diagnosis and safest care possible.
What Is a Cardiac MRI?
A cardiac MRI (magnetic resonance imaging) is a noninvasive imaging test that uses powerful magnets and radio waves to create highly detailed 2-dimensional and 3-dimensional images of the heart and blood vessels.
This test, which is also called cardiovascular magnetic resonance (or CMR), allows doctors to see the heart’s anatomy, motion, blood flow and tissue characteristics in real time.
This makes it one of the most comprehensive tools in pediatric heart imaging and diagnostics. And unlike X-rays or CT scans, cardiac MRI does not use radiation.
How Cardiac MRI Differs From Other MRI Scans
A cardiac MRI is different from other types of MRI because it’s specially designed to evaluate the heart and blood vessels, which are constantly moving.
Here’s more about how it differs:
Focuses on the cardiovascular system: A cardiac MRI looks specifically at the heart muscle, chambers, valves and major blood vessels, while other MRIs focus on areas like the brain, spine, joints or abdomen.
Motion-sensitive imaging: Because the heart is always beating, cardiac MRI uses advanced timing techniques that synchronize image capture with the heartbeat (often using an EKG). This allows doctors to get clear images despite the motion.
Blood flow assessment: Cardiac MRI can measure blood flow, assess how well the heart pumps and show how blood moves through vessels.
Functional information: In addition to anatomy, cardiac MRI provides details about heart function, including muscle thickness, scarring, inflammation and oxygen delivery.
Longer and more specialized: Cardiac MRIs often take longer than routine MRIs (about one hour) and are interpreted by cardiology specialists with expertise in heart imaging.
Why Would a Child or Teen Need a Cardiac MRI?
A cardiac MRI is typically ordered after an initial evaluation with a pediatric cardiologist. Many children never need one, but in some cases, it’s recommended when more detail is needed than an echocardiogram can provide.
Common reasons a child, teen or young adult may need a cardiac MRI include:
- Congenital heart disease, especially complex or repaired defects
- Unexplained fainting (called syncope) or collapse
- Abnormal heart rhythms (called arrhythmias)
- Chest pain during exercise with an unclear cause
- Abnormal findings on an EKG or echocardiogram
- Concerns about safe participation in sports
- Family history of inherited heart conditions or sudden cardiac death
- Suspected cardiomyopathy (diseases of the heart muscle)
In adolescents and young athletes, a cardiac MRI can be especially useful for finding hidden heart conditions that might not cause symptoms but can still increase the risk of problems during intense exercise or sports.
What Can a Cardiac MRI Detect?
Cardiac MRI provides information that other tests might miss. It can help doctors evaluate:
- Heart muscle thickness and strength
- Cardiomyopathies, such as hypertrophic (when the heart muscle becomes abnormally thick) or dilated cardiomyopathy (when the heart becomes enlarged and stretched)
- Scarring or inflammation of the heart muscle (called myocarditis)
- Congenital heart defects and how well the repairs are functioning
- Blood flow through the heart and major vessels
- Abnormal heart structures, including valves and chambers
- Vascular abnormalities, such as issues with the aorta or pulmonary arteries
Because of this level of detail, cardiac MRI can be used to clarify a diagnosis, guide treatment decisions, and help determine whether a child can safely participate in sports or strenuous activity.
Are There Warning Signs That a Child May Need Cardiac Testing?
Most children with heart conditions are identified through routine care or referrals from their pediatrician. However, certain symptoms or red flags should always be evaluated by a healthcare provider, such as a pediatric cardiologist who might decide to use advanced imaging tests to gather more information.
Symptoms that warrant a visit to a pediatrician or pediatric cardiologist, potentially for an MRI, include:
- Fainting or near-fainting, especially during exercise
- Chest pain during physical activity
- Shortness of breath out of proportion to the activity
- Unexplained fatigue or poor exercise tolerance
- Palpitations or rapid heartbeats
- Heart murmurs or abnormal heart sounds
- Family history of inherited conditions or sudden cardiac death suspected to be from a heritable cardiac condition
In many cases, an EKG and echocardiogram are enough to rule out a serious disease. A cardiac MRI is typically used when questions remain or when more precise imaging is needed.
What Is the Experience Like for Children?
A pediatric cardiac MRI is safe and painless, but it does require lying still inside the scanner. The test usually takes about 45 to 90 minutes, depending on the child’s age, how detailed the images need to be and whether contrast dye is used.
Here’s more about what happens during the test:
Before the scan:
Your child will change into a gown and remove any metal objects. Some children, especially younger ones, may receive mild sedation to help them feel more comfortable and stay still, which also helps with the image quality. Older children and teens are usually awake the entire time.
During the MRI:
Your child lies on a padded table that slides into the MRI scanner, which is a large, tube-shaped machine. The test is painless, but the machine makes loud tapping or knocking sounds, so headphones or earplugs are provided. They may be asked to hold their breath for short periods (just a few seconds at a time) while images are taken.
Contrast dye (if needed):
In some cases, a contrast agent is given through an IV to help doctors see blood flow and heart structures more clearly. This is generally very safe and well-tolerated.
After the test:
Once the scan is complete, your child can usually go home right away. If sedation was used, there may be a short recovery period before discharge.
Cardiac MRI is noninvasive, radiation-free and highly detailed, making it a valuable and safe tool for evaluating heart structure and function in children and adolescents. At Stony Brook Children’s Hospital, the test is performed in a family-centered environment, with pediatric-trained staff who specialize in working with children and adolescents.
Expert Pediatric Heart Care at Stony Brook Children’s
Caring for children with heart conditions is a core specialty at Stony Brook Children’s Pediatric Cardiology.
Our services include:
- Advanced cardiac imaging, including cardiac MRI and CT
- Evaluation of congenital, acquired, and inherited heart conditions
- Sports participation assessments
- Long-term management of childhood heart disease
- A dedicated Fetal Heart Program for prenatal diagnosis and care planning
If your child has any of the symptoms described above, a family history of heart disease, or you have questions about heart health and activity, our pediatric cardiology team is here to help provide answers, reassurance, and expert care. Learn more here or call (631) 444-KIDS (5437) to make an appointment.
