Cardiac MRI
Cardiac magnetic resonance imaging (MRI) is a cutting-edge, noninvasive diagnostic tool that provides high-resolution images of the heart while beating. This allows for a thorough and incomparable evaluation of myocardial structure, tissue composition, and function. Our heart specialists and MRI team use radio waves within the MRI scanner to create highly detailed still and dynamic digital renderings of your heart.
At MarinHealth, our heart specialists use cardiac MRI to gain valuable insight into blood flow, myocardial function, and tissue characterization. Cardiac MRI is unmatched in its ability to aid with the diagnosis and treatment planning of many cardiovascular pathologies. This advanced technology is instrumental in the evaluation of heart failure and cardiomyopathies, myocarditis, infiltrative disease, valvular heart disease, congenital heart disease, cardiac masses, and pericardial diseases, among others. It can also monitor patient progress and response to therapies over time.
In doing so, cardiac MRI typically involves using an MRI contrast material (different from that used for CT scanning) injected into a vein. This contrast material quickly passes through heart structures, providing vital information about myocardial tissue composition to the cardiology team. If you have severe kidney disease, though, cardiac MRI may also be performed without the use of contrast material.
Why would a cardiologist order a cardiac MRI?
Cardiac MRI is the gold standard for cardiac imaging in multiple conditions, including the evaluation of heart failure/cardiomyopathies, infiltrative diseases, cardiac masses, valvular diseases, or acute forms of cardiac injury such as myocarditis. It can also be used to evaluate arrhythmias or plan treatment prior to ablations.
It can be beneficial in patients with complex valvular diseases, providing an unmatched volumetric assessment of the heart. Cardiac MRI also provides unique detail of heart muscle function. It is singular in its ability to differentiate normal muscle from scar tissue, quantify blood flow across heart valves, identify tumors and masses, and provide prognostic information in the evaluation of each patient’s unique anatomy and physiology.
What information can a cardiac MRI reveal that other testing may not?
Cardiac MRI is considered the most cutting-edge and advanced imaging modality for evaluating heart size and function. It is also unrivaled in its ability to perform tissue characterization, providing information about scarring or inflammation in the heart muscle. Others have described cardiac MRI as the closest we are to taking the heart of the body, examining it, and putting it back in its place.
How does the test work? How long does it take?
MRI generates images using radio waves transmitted within the magnetic field. Patients lie flat and are placed in the center of the MRI scanner, which looks like a round tube. A unique piece of equipment called a coil is placed on their chest. Patients are instructed to hold their breath for portions of the scan to improve the quality of images.
The MRI machine makes many loud sounds and vibrations which is the machine producing small magnetic field changes. The coil on the chest functions like an antenna that receives the magnetic signals coming from the patient.
These signals are sent to a computer, which builds an image of the part of the body being scanned. A cardiac imaging expert then reviews the images. Most cardiac MRIs require an intravenous injection of a contrast agent. The test takes 60-90 minutes to complete.
Are there any risks?
Cardiac MRI does not involve the use of radiation. The magnetic fields and radio waves used in a cardiac MRI have no significant side effects and are not harmful to most people.
For those with a slight risk of complications, our care team works with all our patients to ensure a safe experience. In some cases, we may modify the cardiac MRI procedure or recommend a different type of imaging test.
People should speak with their doctors before having a cardiac MRI if they:
- Have a pacemaker or other implantable device. The doctor can determine if the device is safe for MRI tests.
- Are in the first three months of pregnancy. Although there are no reports of negative effects on the mother or baby, doctors recommend avoiding MRI unless the potential benefits outweigh the possible risks.
- Are breastfeeding and contrast dye will be used in the MRI. Women can pump breast milk before the exam to feed their infants and after the dye has cleared from their bodies (24 hours).
- Have advanced kidney or liver disease. The dye used during the exam can lead to nephrogenic systemic fibrosis, a rare disease that causes reduced organ function and severe skin problems.
- Although it is extremely rare, the dye may cause side effects, such as:
- Allergic reactions
- Changes in taste
- Dizziness
- Headache
- Nausea
When should I ask my doctor about cardiac MRI?
The role of cardiac MRI should be discussed with your cardiologist. It is instrumental in the diagnosis and treatment of conditions such as heart failure and cardiomyopathies, myocarditis, infiltrative disease, valvular heart disease, congenital heart disease, cardiac masses, pericardial diseases, and other pathologies. It can also be used to monitor patient progress and response to therapies over time. It is also indicated if the underlying cardiac disease or extent of disease is not clear after evaluation with other diagnostic tools, such as echocardiography.
To learn more about cardiac MRI, speak to a cardiologist at MarinHealth’s Haynes Cardiovascular Institute.