How does a heart MRI work?
Unlike some other forms of imaging, a cardiac MRI doesn’t use any radiation. It uses a massive magnet and radio waves to create high-quality images of your heart on a computer.
How do I prepare for a heart MRI?
A heart MRI won’t harm you, but your healthcare provider may ask if you’re pregnant or if you have any metal inside your body. In some cases, an MRI may not be right for you. Some medical devices don’t work right or can interfere while you’re inside an MRI. Be prepared to tell your provider what kind of device you have, since certain types (like an intrauterine device or some pacemakers) aren’t safe in the MRI machine. Your healthcare provider can check their database to see which devices are safe and compatible with having an MRI.
Your provider will also ask about any allergies you have, as well as health problems and surgeries in your history.
If you get nervous or uncomfortable in tight spaces, ask your provider a few days in advance for a pill that will relax you before your cardiac MRI. You can usually pick it up at the pharmacy and take it a half hour before your MRI. Just remember that you’ll need someone to drive you to and from your cardiac MRI if you take a sedative to relax.
What to expect on the date of the heart MRI
- Take your normal medicines and eat regular meals unless your provider tells you not to.
- Don’t wear any jewelry because it will cause problems with the machine’s magnets and images. An MRI can damage jewelry, as well.
- Don’t forget to remove any piercings, glasses, hearing aids or hair barrettes that contain metal.
- Wear clothes that are comfortable and don’t have metal on them. You’ll need to change into a hospital gown if you have metal in your clothes, like the zipper on your jeans or the metal in your bra. You can keep your underwear and socks on.
You can place your clothing, jewelry and other items in a patient locker. Since you can’t take the locker key inside the MRI, your provider can put it in a safe place for you.
Sometimes, your provider may want to give you a contrast substance such as gadolinium, which can make it easier to see some details in your scans. This is different from the contrast used for other imaging like CTs. You’ll get this through an IV in your arm.
You’ll need to lie down on a long platform that will slide into the empty space in the middle of the MRI machine, which is shaped like a large doughnut standing on its side. Some MRI machines (open MRI) don’t make a complete circle around you, which can be easier for people who need or want more space around them.
Your provider may put stickers with electrocardiogram leads on your chest and a belt below your chest to collect information about your heartbeats and breathing during your cardiac MRI scan.
What to expect during the MRI heart scan
Your scans should take a half hour to an hour and a half. The machine may do several scans, with each one lasting a few minutes. Sometimes, your provider will ask you to hold your breath for part of the scan.
You’ll need to lie on your back without moving during scans. The machine is loud and may sound like an electronic video game or something pounding around you, but you’ll be able to communicate (through a microphone and headphones or intercom) with the person operating the machine. They may put a call button in your hand that you can squeeze if you need to contact the person doing the scan. You may be able to listen to music through the headphones they put on you.
What to expect after your heart MRI
Your provider will slide the table you’re on out of the MRI machine. If you had an IV, they’ll remove it. Then you can get your belongings, get back into your clothes and go home.
What are the side effects of a heart MRI?
If you took a sedative to relax, you may feel tired until the effects of the pill wear off. If not, you can return to your normal activities.
If you received contrast through an IV, you might have a metal-type taste for a little while or some bruising or irritation where the IV was put in. Rarely, people may have nausea or a headache from the contrast they got in their IV.
FAQs
For the MRI itself, you will lie on your back in the magnet for approximately 90 minutes – 2 hours. You will be given earplugs as the magnet creates a knocking sound during the exam. You will be asked to hold your breath for about 15-20 seconds at a time; this will be repeated during your scan.
Is there any prep for a cardiac MRI? ›
How do I prepare for a cardiac MRI? There's not a lot of preparation you need to do to prepare for your MRI. You can eat and drink normally in the days leading up to the test. Just before your MRI begins, you'll need to remove all jewellery and any metal objects.
What is the difference between a heart MRI and a cardiac MRI? ›
What is a heart MRI? A heart MRI is a scan of your heart in which radio waves and magnets create images without anything you can see or feel going into your body. A cardiac MRI can show the parts of your heart (including chambers, valves and muscles) and how well they are working ― including how your blood moves.
What should I wear for cardiac MRI? ›
Leave all jewelry at home and wear loose, comfortable clothing. You may need to change into a gown for the procedure. If you have claustrophobia or anxiety, ask your doctor for a mild sedative prior to the exam. What is Cardiac MRI?
How long are you in the machine for a cardiac MRI? ›
For the MRI itself, you will lie on your back in the magnet for approximately 90 minutes – 2 hours. You will be given earplugs as the magnet creates a knocking sound during the exam. You will be asked to hold your breath for about 15-20 seconds at a time; this will be repeated during your scan.
Can you drive home after a cardiac MRI? ›
You should be able to go back to your normal activities straight away. Some exceptions to this are: If you've been given a sedative, you will need to be taken home by a friend or relative. You will be told not to drink alcohol, drive or operate machinery for 24 hours.
What are the pitfalls of cardiac MRI? ›
Being placed in the MRI scanner can induce significant claustrophobia in about 5% of the people who have these tests. It is difficult to monitor patients while they are in the MRI scanner—for instance, the ECG is significantly distorted—so this technique is not suitable for patients who are critically ill.
Is a cardiac MRI better than an echocardiogram? ›
MRI Heart Scans
And cardiac MRI "shows us more than echocardiography or an exercise stress test," Steiner adds. "Those tests have benefits, but MRI shows more in terms of the heart's shape, size, volume, function.
Can a heart MRI show blocked arteries? ›
Vivien Williams: In addition to damage from heart attack or infection, MRI can also show Dr. Shapiro how well the heart pumps, where irregular heart beats originate, the location of blood clots, artery blockages, scar tissue, or even tumors.
Why no caffeine before cardiac MRI? ›
No other preparation is required, except for the cardiac stress perfusion MRI where you will be asked to avoid caffeine for 24–48 hours before the test. Caffeine interferes with the action of adenosine (see Stress Perfusion MRI above), which is used to simulate the stress part of this MRI scan.
It is very important to remain still during your MRI scan as any movement can cause blurring on the images. If you cough during the scan and the images are not clear, we may need to repeat the scan. We will give you a call bell so if you are going to cough a lot then you can press that and we will pause the scan.
What medications interfere with MRI? ›
Please hold the following cardiac medications the morning of the test: Cardizem, Verapamil, Norvasc, Imdur, Isosorbide, Nitroglycerin patches, or Clonidine. If you are claustrophobic, please inform your physician.
What is the position of the patient in a cardiac MRI? ›
Cardiovascular Imaging
The coil must be placed squarely at the center of the MR table. The coil must be placed with the arms raised above the head with the patient in the supine position.
Do you need an IV for a cardiac MRI? ›
If you are asked to remove clothing, you will be given a gown to wear. If you are to have a MRI done with contrast, a nurse will start an intravenous (IV) line in the hand or arm to inject the contrast dye. You will lie on a scan table that slides into a large circular opening of the scanning machine.
Why would a cardiologist order a cardiac MRI? ›
Cardiac MRI is considered the gold standard for evaluation of heart size and function. Cardiologists can use it to evaluate an arrythmia (heart rhythm disorder) evaluation. They can also use it to help plan treatment for arrythmias, such as ablation, which is a nonsurgical treatment.
Can you eat or drink before a cardiac MRI? ›
Do not drink or eat anything with caffeine for 24 hours before the MRI, as caffeine may affect the results. This includes coffee, tea, soda, and chocolate. Do not eat for four hours before the MRI.
