Magnetic Resonance Imaging (MRI)
What is it for?
MRI (Magnetic Resonance Imaging) is a scan that produces high resolution images of the heart and blood vessels. Loyola University Health System is one of only a few medical centers in the state that provides advanced cardiac MRI testing. The procedure can be used for several reasons, for example, to determine the cause of a patient's heart failure, to help plan an ablation procedure to treat an irregular heartbeat or to quantify the amount of muscle damaged in a heart attack. Other conditions that can be diagnosed include: congenital heart disease, pericardial disease, coronary artery disease and arrhythmia.
How is it done?
The patient lies on a table that slides into a large round scanner that is open on both ends. The machine uses magnetic force to align the hydrogen atoms in your body. A radiofrequency pulse is sent through you, affecting the alignment of your atoms. The signal that is generated is picked up by a scanner and interpreted by a computer to form still or moving images. Sometimes patients also get a contrast dye to help assess damaged areas of the heart. An MRI usually takes 30 to 60 minutes, but some can take longer.
What are the risks?
The MRI itself is noninvasive. Because of the powerful magnet, you must be careful with metal objects in the room that has the MRI scanner.
You will receive a comprehensive screening and all metallic implants are individually evaluated to see if you can have an MRI safely. You may not receive an MRI if you:
- Have an implanted metallic device like a pacemaker, defibrillator or other implanted electronic devices
- Have a ferromagnetic metal inside the body, e.g., metal shavings in the eyes from machining
- Have a bullet or metal shrapnel
- Are pregnant (Patients who are uncertain will be required to undergo a screening urine or blood pregnancy test)
An MRI is safe with joint replacements, coronary stents, sternal wires, heart closure devices and most artificial heart valves.