What is magnetic resonance imaging (MRI)?

Magnetic resonance imaging (MRI) uses a powerful magnetic field, radio frequency pulses, and a computer to produce detailed pictures of organs, soft tissues, bone and virtually all other internal body structures. Detailed MR images allow physicians to better evaluate various parts of the body and certain diseases that may not be assessed adequately with other imaging methods such as x-ray, ultrasound or computed tomography (also called CT or CAT scanning).

Magnetic resonance imaging (MRI) is an imaging technique primarily used in radiology to visualize the structures and functions of the body. MRI provides greater contrast between the soft tissues of the body than CT technology, making it especially useful in neurological, musculoskeletal, cardiovascular, and oncological imaging.

Magnetic resonance imaging (MRI) is a test that uses a magnetic field and pulses of radio wave energy to make pictures of organs and structures inside the body.

In many cases, MRI gives different information about structures in the body than can be seen with an X-ray, ultrasound, or computed tomography (CT) scan. MRI also may show problems that cannot be seen with other imaging methods.

For an MRI test, the area of the body being studied is placed inside a special machine that has a strong magnet. In some cases, a dye (contrast material) may be used during the MRI to show pictures of organs or structures more clearly.

Photographs or films of certain views can also be made. Information from an MRI can be saved and stored on a computer for more study.

MRI can be used to look for problems such as bleeding, tumors, infection, blockage, or injury in the brain, organs and glands, blood vessels, and joints.

Magnetic resonance imaging (MRI) is a diagnostic procedure that uses a combination of a large magnet, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.

Magnetic resonance imaging (MRI) is used to give a picture of the internal organs and structures of a body. It can show bleeding, tumors, injuries, or infections. It is sometimes ordered to help doctors obtain more information that can't be gathered from X-rays, ultrasounds, or CT scans.

(This answer provided for NATA by the Gustavus Adolphus College Athletic Training Education Program.)

Magnetic resonance imaging (MRI) creates an image similar to that produced by a computed tomography (CT) scan, although the technique is quite different. Rather than using x-rays, the MRI machine relies on a strong magnetic field. Tissues give off minute electromagnetic waves in frequencies that differ according to the type involved. A computer tallies the vibrations and uses this information to create cross-sectional images on many different planes. These remarkably detailed pictures can show the difference between brain tissue and tumors and highlight areas of the brain that have been damaged by a stroke or other neurological conditions.

In conjunction with radio wave pulses of energy, an MRI scanner can pick out a very small point inside a patient's body to determine what type of tissue is present. The small point might be a cube measuring only half a millimeter on each side. Point by point, the MRI system goes through the patient's entire body, building up a two-dimensional or three dimensional map of tissue types. Then, the MRI can integrate all this information to create 2-D images or 3-D models.

MRI scans provide unparalleled views inside the human body. The level of detail is extraordinary compared with any other type of body imaging. MRI is the method of choice to diagnose many injuries and conditions because of the exams incredible ability to be tailored to the particular medical question that needs answering. Changing MRI exam parameters also can cause tissues in the body to change appearances. This is helpful to a radiologist (who reads the MRI) when he or she is trying to determine if something is normal. We know that when a technician does "A," normal tissue will look like "B." If the tissue doesn't look like "B," there might be an abnormality. MRI scans can also image flowing blood in virtually every part of the body. This allows us to see the arterial system but not the tissue around it. In many cases, MRIs can do this without the need for a contrast injection, which is required in vascular radiology.