Magnetic resonance imaging (MRI)
is a test that provides pictures of organs and structures inside the body.
It produces these images by using a magnetic field and pulses of radio wave
energy. In many cases, MRI provides information that cannot be obtained from
X-ray tests.
For an MRI test, the area of the
body being studied is positioned inside a strong magnetic field. MRI can detect
tumors, infection, and other types of tissue disease or damage. It can also
help diagnose conditions that affect blood flow. Tissues and organs that contain
water provide the most detailed MRI pictures, while bones and other hard materials
in the body do not show up well on MRI pictures. For these reasons, MRI is
most useful for detecting conditions that increase the amount of fluid in
a tissue, such as an infection, tumors, and internal bleeding. Information
from an MRI scan can be saved and stored on a computer for further study.
Photographs of selected views can also be made.
In some cases, a contrast material may
be used during the MRI scan to enhance the images of certain structures. The
contrast material may help evaluate blood flow, detect some types of tumors,
and locate areas of inflammation.
While MRI is a safe and valuable
test for looking at structures and organs inside the body, it is very expensive
and not always available outside of large cities and major medical centers.
