Magnetic resonance imaging, also referred to as MRI, is a diagnostic test that uses radio waves, magnetic fields, and computer software to create highly detailed cross-sectional images of the body's structures.
A special type of MRI called magnetic resonance angiography, or MRA, is used to visualize the structure of and blood flow through blood vessels.
MRI does not require catheters or radiation and is commonly used to assess the function of the heart and to diagnose numerous cardiac conditions.
Magnetic resonance imaging (MRI) is a painless, safe, and radiation-free test that provides physicians with detailed, cross-sectional images of internal organs and the spine.
An MRI works by using a large magnetic field, pulses of radio waves, and a computer to produce clear images of the heart's chambers and its arteries and veins.
There are usually no tests, diets, or medications required before undergoing an MRI. The patient should:
Remove any jewelry;
Inform the physician or technician if he or she has a pacemaker or other implanted devices, such as joints, pins, clips, or valves, which can distort the reading;
Inform the physician if he or she is claustrophobic; and
Inform the physician if she is pregnant.
WHAT TO EXPECT
An MRI is usually administered in a hospital or an outpatient healthcare facility.
Because MRI images can become blurred with motion, the patient must lie still, for which the technologist may offer the patient a sedative.
The patient is asked to lie on his or her back on a narrow table that slides into a tunnel-like tube within the MRI scanner. The scanner creates a magnetic field and directs radio waves at the area being scanned. Throughout the procedure, the scanner produces humming and thumping sounds.
An MRI usually lasts between 30 and 90 minutes. The only discomfort associated with the test is stiffness in the back caused by having to lie still on a hard surface for an extended period.
Unless a sedative is given, patients can generally resume usual activities and diet immediately after the test.
There are usually no complications associated with this test.